Title:
METHOD OF CARPET SEAMING
United States Patent 3660191
Abstract:
Adjacent sections of carpeting are joined in a seam between abutting edges of the carpet sections by a strip of heat activatable adhesive tape applied to the back sides of the carpet sections with the carpet sections lying face-up on a surface while heating the tape from its non-adhesive back side.
US Patent References:
Process for face-seaming carpeting
Burgess - December 1968 - 3415703
Method of seaming vinyl-backed materials
Studer - November 1965 - 3219508
Process for face-seaming carpeting
Burgess - December 1968 - 3415703
Method of seaming vinyl-backed materials
Studer - November 1965 - 3219508
Inventors:
Shimota, Robert E. (Fox River Grove, IL)
Dritt, Harry J. (Wheaton, IL)
Dritt, Harry J. (Wheaton, IL)
Application Number:
04/882985
Publication Date:
05/02/1972
Filing Date:
12/08/1969
View Patent Images:
Export Citation:
Assignee:
The Kendall Company (Boston, MA)
Primary Class:
Other Classes:
156/324.400, 156/304.400, 156/304.600
International Classes:
A47G27/04; A47G27/00; D06H5/00
Field of Search:
156/304,306,157,505,152 117/68.5
Primary Examiner:
Quarforth, Carl D.
Assistant Examiner:
Schafer R. E.
Claims:
We claim
1. A method of face seaming abutting carpet segments comprising the steps of:
2. A method of face seaming abutting carpet segments comprising the steps of:
3. The method of claim 2 wherein a substantially flat, planar firm supporting surface is positioned against the back side of the tape while applying pressure down upon said portions of the carpet segments along the abutting carpet edges.
4. A method of face seaming adjacent carpet segments while the carpet segments are placed face-up over a surface with edges of said carpet segments abutting, comprising the steps of:
5. The method of carpet seaming of claim 4 wherein said heating means is caused to be heated by electrical means located in said heating means.
6. A method of face seaming adjacent carpet segments positioned face-up over a surface comprising the steps of:
7. The method of claim 6 wherein the portions of said carpet segments and said strip of tape are raised to a distance above said surface so that the edges of the raised carpet portions, when positioned parallel to the top surface of the heating means, no longer overlap.
8. The method of claim 7 wherein the portions of said carpet segments are raised to a distance above said surface so that the edges of the raised carpet portions are in abutment with each other when positioned upon the overlying tape upon the top surface of the heating means.
9. The method of carpet seaming of claim 6 which includes the further step of flattening the carpeting after each carpet segment has become adhesively bonded to the adhesive tape.
10. The method of carpet seaming of claim 6 wherein said heating means is moved away from said heat activated adhesive along the back side of the strip of tape underneath the carpeting by guiding means.
11. The method of carpet seaming of claim 10 wherein said guiding means is attached to said heating means and extends around the lateral edge of said strip of tape through an opening between the edges of the carpet segments to a point above said carpet segments, said opening being created progressively between said carpet segments as said heating means is moved by said guiding means which temporarily holds up an edge portion of at least one of said carpet segments so that the carpet segments are temporarily separated and said opening being progressively closed behind said guiding means to place the edges of said carpet segments into abutment in contact with the adhesive surface of the tape on the top surface of the heating means.
12. A method of face seaming adjacent carpet segments emplaced over a surface comprising the steps of:
13. A method of face seaming carpet segments positioned face-up on a surface comprising the steps of:
14. A method of face seaming adjacent carpet segments positioned face-up comprising the steps of;
1. A method of face seaming abutting carpet segments comprising the steps of:
2. A method of face seaming abutting carpet segments comprising the steps of:
3. The method of claim 2 wherein a substantially flat, planar firm supporting surface is positioned against the back side of the tape while applying pressure down upon said portions of the carpet segments along the abutting carpet edges.
4. A method of face seaming adjacent carpet segments while the carpet segments are placed face-up over a surface with edges of said carpet segments abutting, comprising the steps of:
5. The method of carpet seaming of claim 4 wherein said heating means is caused to be heated by electrical means located in said heating means.
6. A method of face seaming adjacent carpet segments positioned face-up over a surface comprising the steps of:
7. The method of claim 6 wherein the portions of said carpet segments and said strip of tape are raised to a distance above said surface so that the edges of the raised carpet portions, when positioned parallel to the top surface of the heating means, no longer overlap.
8. The method of claim 7 wherein the portions of said carpet segments are raised to a distance above said surface so that the edges of the raised carpet portions are in abutment with each other when positioned upon the overlying tape upon the top surface of the heating means.
9. The method of carpet seaming of claim 6 which includes the further step of flattening the carpeting after each carpet segment has become adhesively bonded to the adhesive tape.
10. The method of carpet seaming of claim 6 wherein said heating means is moved away from said heat activated adhesive along the back side of the strip of tape underneath the carpeting by guiding means.
11. The method of carpet seaming of claim 10 wherein said guiding means is attached to said heating means and extends around the lateral edge of said strip of tape through an opening between the edges of the carpet segments to a point above said carpet segments, said opening being created progressively between said carpet segments as said heating means is moved by said guiding means which temporarily holds up an edge portion of at least one of said carpet segments so that the carpet segments are temporarily separated and said opening being progressively closed behind said guiding means to place the edges of said carpet segments into abutment in contact with the adhesive surface of the tape on the top surface of the heating means.
12. A method of face seaming adjacent carpet segments emplaced over a surface comprising the steps of:
13. A method of face seaming carpet segments positioned face-up on a surface comprising the steps of:
14. A method of face seaming adjacent carpet segments positioned face-up comprising the steps of;
Description:
BACKGROUND OF THE INVENTION
This invention relates to methods of seaming together abutting sections of carpeting by means of heat activatable adhesive tape.
The splicing or seaming of adjacent carpet segments through the use of heat activatable adhesive tape has historically been accomplished by either of two methods. One method previously employed entails placing both carpet segments in a face-down position with adjacent edges in an abutting relationship. A strip of tape having heat activatable adhesive on one side is laid on the carpet backing with the adhesive coated tape side facing and covering the abutting edges of the carpeting. The tape is then bonded to the carpet backing by application of a heating element to the non-adhesive side of the tape such that the adhesive in contact with the carpet backing is rendered tacky and, upon removal of the heating element, adherent to the carpet backing. Following this operation, the seamed carpeting must be returned to a face-up position for use at its desired site. The second prior method of rug seaming with hot melt adhesive tape is performed while adjacent carpet segments lie face-up on a substrate with edges initially placed in abutment. The abutting edges are positioned directly over a strip of hot-melt adhesive tape laid along a surface so that its adhesive coated surface contacts the carpet back sides. An example of this second method is disclosed in U.S. Pat. No. 3,415,703, issued to Charles D. Burgess on Dec. 10, 1968. In the method disclosed, the adhesive material is made tacky by application of a heated sadiron directly to the hot-melt adhesive. This is accomplished by rolling back the adjacent carpet edges, holding a heated sadiron in contact with the adhesive surface of the seaming tape long enough to render the adhesive material tacky, removing the heated sadiron from the adhesive surface, and re-establishing the abutting relationship of the carpet edges in contact with the adhesive surface of the tape.
It is immediately obvious that each of these prior carpet seaming techniques has serious drawbacks and disadvantages. The first method cannot be performed with the carpeting in place at its permanent site. The carpet segments must be turned face-down before the seaming operation takes place. After the tape is affixed to the carpet backing, the connected carpeting must be turned back to a face-up position, and installed at its intended site. However, most carpeting is somewhat thick and heavy. Consequently, it is unwieldly, awkward to transport, and difficult to manipulate. Therefore, these transportation and turning requirements present a highly objectionable feature of this first method. Considerable energy must be exerted in lifting and manipulating the carpeting. Also, the bond between the tape and carpet segments may be weakened or destroyed during such moving, causing the seam between the carpet segments to be broken. Accordingly, it would be preferable in many instances to carpet seam with a method that can be performed at the site where the carpet is to remain, with the carpeting laid face-up and moving requirements minimized.
The second method mentioned above eliminates some undesirable carpet moving requirements, since the operation may be performed with the carpeting laid face-up at its intended site. However, in this method the abutting carpet edges are rolled back from each other, and the adhesive is brought to a tacky state by directly contacting it with a heated sadiron. The carpet edges must be placed back into an abutting relationship and pressed into the adhesive material while it is still in a thermally softened, tacky condition. A firm bond may not be created unless the carpet backing is pressed into the adhesive soon after removal of the heating iron. Furthermore, in the second method, the hot sadiron must be placed directly on the adhesive, transforming the adhesive to a tacky material which sticks to the heating iron and whatever else it contacts. The adhesive transferred to the heating surface of the sadiron obviously is undesirable and may reduce the efficiency of the sadiron. Since the tacky adhesive may be exposed and unprotected on the heated sadiron for at least a short period after removal of the hot sadiron from the adhesive surface, it is vulnerable to accidental spreading onto other objects in the surrounding area, resulting in an extremely undesirable and messy situation.
SUMMARY OF THE INVENTION
The method of the present invention avoids the problems encountered in prior methods of connecting carpet segments by hot-melt adhesive tape. Carpet seaming may be accomplished according to this invention while the carpet sections are laid face-up in place at their desired permanent site. The adhesive is heated to a tacky state without direct contact between it and the heating means, eliminating the possibility of adhesive material being transferred to the heating means. Thus, any potentially messy situation resulting from exposure of tacky adhesive on the heating means to foreign objects is avoided. The possibility of forming an imperfect seam by reason of the adhesive solidifying before being firmly anchored to the back of each of the carpet segments may be substantially eliminated through at least one variation of this method by placing the carpet edges into abutment with each other and pressing them onto the surface of the adhesive while the seaming tape is on the heating means. This method also eliminates the necessity for turning the carpeting before and after the seaming operation, thus simplifying the operation and reducing the possibility of the bond between the tape and carpeting being weakened or broken.
In accordance with the present invention, the seaming of two adjacent pieces of carpeting along abutting edges is achieved by heating and applying a heat activatable adhesive tape to the back sides of the carpet segments along their abutting edges while the carpeting rests face-up on a substrate, possibly at its desired permanent site. In preparation for this seaming operation, two carpet segments are laid on a floor, or other substrate, face-up in contact along the area where they are to be joined. A strip of tape coated on one side with heat activatable adhesive is placed on the floor beneath the edges of the segments of carpeting which are to be joined in abutment, with the adhesive surface of the tape directed toward the carpet backing, and with each of the carpet segments overlying a portion of the adhesive surface of the tape. The tape including the adhesive is heated conductively from its back side by a heating means positioned underneath the tape, the heating means having a top surface in contact with the backing of the tape. The top surface of the heating means supports the portions of the tape and carpet segments overlying the heating means and separates these portions from the surface over which the carpet is to be installed. In at least one variation of this method the top surface may provide a surface against which the tape and carpet segments may be pressed as the heating means is moved along the tape for the length of the seam. The heating means may be guided along the length of the seam while it is underneath the tape and carpet segments by a guide means offset from the side thereof to project upwardly therefrom above the face of the carpet between the carpet edges. At least one of the carpet edges is raised to provide an opening between the carpet edges through which the guide means extends. One type of heating means that can be utilized to perform the method of this invention is a thermal activator described in detail in another patent application, Ser. No. 882,944, filed by Mr. Robert E. Shimota, one of the joint applicants in the present case. That thermal activator has a substantially flat planar supporting and heating surface and a handle attachment which may extend above the surface and the carpet for guiding the activator heater body along the edge underneath the tape in making the seam. To perform the present method, the heater body of such a thermal activator is positioned under the seaming tape so that the non-adhesive side of the tape rests on the activator's top surface beneath the carpet segments to be joined. The seaming tape is placed in a threading relationship with the handle attachment section of the activator, which helps guide succeeding portions of tape into proper alignment for seaming the carpet edges as the activator is moved forward under the edges of the carpet segments to be seamed. Before such movement is initiated, the activator is sufficiently heated so that contact of the non-adhesive side of the seaming tape by the activator's top surface for a reasonably short period brings to a tacky condition the adhesive on the other side of the tape. The minimum temperature a heating means must attain to perform this method is determined by the melting point of the adhesive utilized. It has been found that to make tacky most heat-activatable adhesives, the heating means must be brought to a temperature of at least 200° F. However, this invention is not limited to a method requiring the heating means to necessarily be heated to at least 200° F., as the essence of this invention does not reside in the tackifying temperature of the adhesive used on the seaming tape. The maximum temperature is determined largely by the type of carpet backing on which the tape is to be applied. After the heating means is sufficiently heated, it is moved forward under the seaming tape. As the heating means proceeds, the forward portion of the seaming tape, i.e. that part of the seaming tape which extends in front of the heater, is progressively brought into position between the top surface of the heater body and the carpet backing so that it may be heated to a tacky condition. Concurrently, as the heating means proceeds, portions of the tape trail off the rear end of the heater body with its adhesive in a tacky condition. The carpet segments are placed into abutment either on the heating means or behind the heating means as it passes and are pressed into the tacky adhesive. Then the adhesive at points on the tape passed by the heater body cools and solidifies, bonding the tape to the carpet backs and seaming the adjacent segments of carpeting along their abutting edges. A protective element may cover the base of the heating means to help avoid damage to floors or other surfaces which might otherwise contact the heated instrument. By the method of this invention carpet seaming is accomplished simply, cleanly, and with assuredness that strong bonding has been achieved between the tape and carpeting.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features will appear from the following description of this invention, detailed in reference to the accompanying drawings, in which:
FIG. 1 illustrates the relationship between the carpet segments, seaming tape, and one type of heating means in position for performance of one variation of the method of carpet seaming of this invention.
FIG. 2 shows a cross sectional view as taken on line 2--2 of FIG. 1.
FIG. 3 illustrates the relationship between the carpet segments, seaming tape and heating means in position for performance of another variation of the method of this invention.
FIG. 4 illustrates another type of heating means in position under the carpet segments and seaming tape for performance of the method of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The heating means utilized in the method of this invention may be any one of a number of devices which are capable of heating the adhesive by contacting the non-adhesive back side of the seaming tape under the carpet segments and of being guided along under the tape and carpeting by a person above the carpeting. One type heating means suitable for this method of carpet seaming is shown in FIGS. 1-3. That heating means is a thermal activator 1 having a heater body 2 with a flat top surface 3 and a downwardly sloping trailing top surface 4. The activator 1 includes a heat protective means 5 on the bottom surface 6 of the heater body 2. The activator 1 also includes a guiding handle 7 which is held above the heater body 2 by an attachment section 8 fastened to the side of the heater body 2. The heater body 2 is generally constructed of a heat conductive, preferably metallic, material. It may be heated electrically, with electric current being carried to a heating element within the heater body by insulated conducting wires 9, or non-electrically. Another type heating means suitable for the method of this invention is a relatively flat heater strip 10 such as shown in FIG. 4. The heater strip 10 may be flexible, being comprised of a heating element, such as an electric coil, enclosed within a heat resistant, heat conducting material, such as silicon rubber. If desired, a thermally insulating protective layer of material may cover one side of the heater strip to prevent heat damage to a surface on which the heater strip is laid.
A preferred variation of the method of carpet seaming in accordance with this invention is illustrated in FIGS. 1 and 2. This variation permits abutting carpet segments to be pressed onto the tacky adhesive of the seaming tape on the top surface of the heating means. To accomplish this, the carpet segments 11,12 to be joined are laid face-up in an adjacent arrangement on a floor or other surface on which a carpet might rest. In order that the edges of the carpet segments can be raised and placed into abutment, as shown at 13, on the top surface of the heater body, the carpet segments should first be positioned so that their edges may overlap, as shown at 14, when not raised to the height of the top surface of the heater body 2. The amount of overlapping of the carpet segments is determined by the height of the heater body, it being necessary that the edges of the carpet segments are capable of being placed into abutment along at least a portion of the top surface of the heater body. The heating means 1 is inserted between the carpet segments so that the heater body 2 is under the carpet segments to be joined and under a portion of a strip of heat activatable adhesive tape 15. The adjacent edges of the carpet segments to be joined are raised above the top surface of the heater body 2 and placed in abutment contacting at least a portion of the tape strip on the top surface of the heater body. The above-mentioned portion of the strip of heat activatable adhesive tape is positioned between the heater body and the abutting carpeting, with the carpeting on each side of the abutting edges covering and contacting approximately half the tape's adhesive coated surface. The forward portion of tape extending to the front of the heater body (to the right as shown in FIG. 1) may be laid out under the carpet sections or may extend up between the carpet sections, possibly into a tape dispensing means.
The heating means should include some type of guide means by which the heater body may be moved along under the carpeting where the sections are to be joined. When a thermal activator 1 is utilized as the heating means, a handle 7 is provided which is held above the carpeting by a handle attachment 8 extending between the carpet segments through an opening created by the raising of at least one of the carpet segments to connect to one side of the heater body.
After the above-described relationship between the floor, heating means, tape, and carpet segments has been established, the heater body 2 is heated to a temperature sufficient to bring the heat activatable adhesive 16 to a tacky condition by contacting the non-adhesive surface 17 of the tape with the heating means' trailing top surface 4 or top surface 3 for a reasonably short time. Heating of the heater body may be accomplished by closing an electric circuit directed to a heating element through insulated conducting wires 9 entering the heating means through the handle section. When the heater body has been sufficiently heated, it is gradually moved forward (to the right as viewed in FIG. 1). As the heating means proceeds, successive forward portions of tape strip are threaded into proper alignment between the heater body and the carpet segments. Each succeeding tape segment is retained between the carpet and heater body long enough to insure that that segment's adhesive coating becomes tacky. Since the carpet segments are brought into abutment above a portion of the top surface of the heater body, the carpeting can be pressed into the tacky adhesive of the tape against the surface of the heater body. Thus, the adhesive definitely exists in a tacky condition for a time while directly contacting the backing of the abutting carpet segments. When the heated activator moves past an activated segment of tape, the adhesive on that segment cools and solidifies, adhering to the backing of each of the carpet segments and seaming them together along the abutting edges. As indicated, downward pressure may be exerted on portions of the carpeting while the adhesive is in its tacky condition and the portions of the abutting carpet segments are overlying portions of the top surface in order to insure a firm connection between the tape and carpet backing. By continuing this procedure as the activator is moved along the length of the desired seam, the carpet segments become securely held together or seamed along their abutting edges. The slope of the heater body's trailing top surface 4 may permit a smooth transition of the seamed carpeting from a position above the heater body to the floor, so that the seam will not be weakened by a sudden drop.
The top surfaces of the heater body of the thermal activator provide solid support for the seaming tape, when pressure, such as hand pressure, is applied to press the carpet backing down onto the tape during performance of this variation of the seaming method. This support is especially important when the seaming operation is being performed on carpeting over a resilient or spongy pad, such as when seaming over a carpet underlay pad. In prior art methods of carpet seaming, such as the Burgess method discussed above, if pressure were applied to press the carpeting down onto the tape while lying on a resilient pad, there would be no solid backing to support the tape. The resilient pad would give way under the pressure, reducing the effectiveness of such pressure to increase the bonding between the tape and the carpet backing. With the support provided by the heater body of the activator in the present invention, however, the effectiveness of such pressure in improving the bonding between the tape and the carpet backing is substantially increased. Of course, after a firm seam has been created by this variation of the method, it may be necessary to spread the carpeting slightly to flatten it and avoid any possible bulges produced by placing in abutment and seaming along the edges which once had overlapped each other.
In instances where, due to carpet bulk or size or other reasons, it is impossible or impractical to provide for overlap of the carpet segments along the edges to be seamed before they are raised above the heater body, a variation of the method of this invention may be employed which differs slightly from the above-described procedure. This variation may be understood by reference to FIG. 3. In this variation, the heating means, seaming tape, and carpet segment are arranged in basically the same relationship with respect to each other as for the above-described procedure, that is the heater body 2 is positioned under the carpet segments 11,12 at the edges to be seamed, with the tape strip 15 resting on the top surface of the heater body with its adhesive surface directed toward the carpet backing. However, in this variation the carpet segments are placed in abutment instead of being overlapped along the edges to be joined before being placed above the top surface of the heater body. Therefore, they cannot be brought into close abutment when raised and placed above the heater body top surface. Instead, a gap 18 exists between the edges of the carpet segments when positioned above the top surface of the heater body. Occasionally the carpet segments may be stretched to close the gap, in which cases the previously described procedure may be employed to seam the carpet segments along the edges brought into abutment by stretching the carpeting. Frequently, however, such stretching of the carpeting cannot be easily accomplished. Then it is necessary to heat the adhesive 16 on the seaming tape to a tacky condition by contacting the non-adhesive surface 17 of the tape with the surface of the heater body 2 but to not allow the carpet backing to be pressed into the tacky adhesive until after the heater body has been moved out from under that tackified portion of the adhesive tape strip. When the heater body has been moved forward out from under that tackified portion of the tape strip, the carpet edges can be lowered down into abutment and pressed into the still tacky adhesive behind the trailing edge of the heater body. Then as the adhesive cools and bonds to the carpet backing the carpet segments become firmly seamed along the abutting edges.
The heater strip 10 shown in FIG. 4 may be employed as an alternative to the thermal activator as the heating means in the performance of either of the above-described variations of the method of this invention. The same basic steps as explained above are followed when performing this method with a heater strip 10, except that a person may direct the movement of the heater strip by pulling a cord, strap, wire, or other similar guide means, such as 19, attached to the heater strip and extending under the carpeting. Of course, a similar guiding means could be used with other types of heating means as well.
It is particularly noteworthy that this method may be carried out after the carpeting is positioned at its desired permanent site. Also, by this method, the danger of a messy situation resulting from exposed tacky adhesive on the heating means is eliminated. This method may be employed to perform the described operations in small areas within a home, in large areas such as assembly halls, or at other locations where carpet seaming is desired.
A person skilled in the art of this invention will recognize that there are many variations within the scope of this invention which may be used to achieve the desired objectives. This invention is intended to include all such variations, limited only to the scope defined in the following claims.
This invention relates to methods of seaming together abutting sections of carpeting by means of heat activatable adhesive tape.
The splicing or seaming of adjacent carpet segments through the use of heat activatable adhesive tape has historically been accomplished by either of two methods. One method previously employed entails placing both carpet segments in a face-down position with adjacent edges in an abutting relationship. A strip of tape having heat activatable adhesive on one side is laid on the carpet backing with the adhesive coated tape side facing and covering the abutting edges of the carpeting. The tape is then bonded to the carpet backing by application of a heating element to the non-adhesive side of the tape such that the adhesive in contact with the carpet backing is rendered tacky and, upon removal of the heating element, adherent to the carpet backing. Following this operation, the seamed carpeting must be returned to a face-up position for use at its desired site. The second prior method of rug seaming with hot melt adhesive tape is performed while adjacent carpet segments lie face-up on a substrate with edges initially placed in abutment. The abutting edges are positioned directly over a strip of hot-melt adhesive tape laid along a surface so that its adhesive coated surface contacts the carpet back sides. An example of this second method is disclosed in U.S. Pat. No. 3,415,703, issued to Charles D. Burgess on Dec. 10, 1968. In the method disclosed, the adhesive material is made tacky by application of a heated sadiron directly to the hot-melt adhesive. This is accomplished by rolling back the adjacent carpet edges, holding a heated sadiron in contact with the adhesive surface of the seaming tape long enough to render the adhesive material tacky, removing the heated sadiron from the adhesive surface, and re-establishing the abutting relationship of the carpet edges in contact with the adhesive surface of the tape.
It is immediately obvious that each of these prior carpet seaming techniques has serious drawbacks and disadvantages. The first method cannot be performed with the carpeting in place at its permanent site. The carpet segments must be turned face-down before the seaming operation takes place. After the tape is affixed to the carpet backing, the connected carpeting must be turned back to a face-up position, and installed at its intended site. However, most carpeting is somewhat thick and heavy. Consequently, it is unwieldly, awkward to transport, and difficult to manipulate. Therefore, these transportation and turning requirements present a highly objectionable feature of this first method. Considerable energy must be exerted in lifting and manipulating the carpeting. Also, the bond between the tape and carpet segments may be weakened or destroyed during such moving, causing the seam between the carpet segments to be broken. Accordingly, it would be preferable in many instances to carpet seam with a method that can be performed at the site where the carpet is to remain, with the carpeting laid face-up and moving requirements minimized.
The second method mentioned above eliminates some undesirable carpet moving requirements, since the operation may be performed with the carpeting laid face-up at its intended site. However, in this method the abutting carpet edges are rolled back from each other, and the adhesive is brought to a tacky state by directly contacting it with a heated sadiron. The carpet edges must be placed back into an abutting relationship and pressed into the adhesive material while it is still in a thermally softened, tacky condition. A firm bond may not be created unless the carpet backing is pressed into the adhesive soon after removal of the heating iron. Furthermore, in the second method, the hot sadiron must be placed directly on the adhesive, transforming the adhesive to a tacky material which sticks to the heating iron and whatever else it contacts. The adhesive transferred to the heating surface of the sadiron obviously is undesirable and may reduce the efficiency of the sadiron. Since the tacky adhesive may be exposed and unprotected on the heated sadiron for at least a short period after removal of the hot sadiron from the adhesive surface, it is vulnerable to accidental spreading onto other objects in the surrounding area, resulting in an extremely undesirable and messy situation.
SUMMARY OF THE INVENTION
The method of the present invention avoids the problems encountered in prior methods of connecting carpet segments by hot-melt adhesive tape. Carpet seaming may be accomplished according to this invention while the carpet sections are laid face-up in place at their desired permanent site. The adhesive is heated to a tacky state without direct contact between it and the heating means, eliminating the possibility of adhesive material being transferred to the heating means. Thus, any potentially messy situation resulting from exposure of tacky adhesive on the heating means to foreign objects is avoided. The possibility of forming an imperfect seam by reason of the adhesive solidifying before being firmly anchored to the back of each of the carpet segments may be substantially eliminated through at least one variation of this method by placing the carpet edges into abutment with each other and pressing them onto the surface of the adhesive while the seaming tape is on the heating means. This method also eliminates the necessity for turning the carpeting before and after the seaming operation, thus simplifying the operation and reducing the possibility of the bond between the tape and carpeting being weakened or broken.
In accordance with the present invention, the seaming of two adjacent pieces of carpeting along abutting edges is achieved by heating and applying a heat activatable adhesive tape to the back sides of the carpet segments along their abutting edges while the carpeting rests face-up on a substrate, possibly at its desired permanent site. In preparation for this seaming operation, two carpet segments are laid on a floor, or other substrate, face-up in contact along the area where they are to be joined. A strip of tape coated on one side with heat activatable adhesive is placed on the floor beneath the edges of the segments of carpeting which are to be joined in abutment, with the adhesive surface of the tape directed toward the carpet backing, and with each of the carpet segments overlying a portion of the adhesive surface of the tape. The tape including the adhesive is heated conductively from its back side by a heating means positioned underneath the tape, the heating means having a top surface in contact with the backing of the tape. The top surface of the heating means supports the portions of the tape and carpet segments overlying the heating means and separates these portions from the surface over which the carpet is to be installed. In at least one variation of this method the top surface may provide a surface against which the tape and carpet segments may be pressed as the heating means is moved along the tape for the length of the seam. The heating means may be guided along the length of the seam while it is underneath the tape and carpet segments by a guide means offset from the side thereof to project upwardly therefrom above the face of the carpet between the carpet edges. At least one of the carpet edges is raised to provide an opening between the carpet edges through which the guide means extends. One type of heating means that can be utilized to perform the method of this invention is a thermal activator described in detail in another patent application, Ser. No. 882,944, filed by Mr. Robert E. Shimota, one of the joint applicants in the present case. That thermal activator has a substantially flat planar supporting and heating surface and a handle attachment which may extend above the surface and the carpet for guiding the activator heater body along the edge underneath the tape in making the seam. To perform the present method, the heater body of such a thermal activator is positioned under the seaming tape so that the non-adhesive side of the tape rests on the activator's top surface beneath the carpet segments to be joined. The seaming tape is placed in a threading relationship with the handle attachment section of the activator, which helps guide succeeding portions of tape into proper alignment for seaming the carpet edges as the activator is moved forward under the edges of the carpet segments to be seamed. Before such movement is initiated, the activator is sufficiently heated so that contact of the non-adhesive side of the seaming tape by the activator's top surface for a reasonably short period brings to a tacky condition the adhesive on the other side of the tape. The minimum temperature a heating means must attain to perform this method is determined by the melting point of the adhesive utilized. It has been found that to make tacky most heat-activatable adhesives, the heating means must be brought to a temperature of at least 200° F. However, this invention is not limited to a method requiring the heating means to necessarily be heated to at least 200° F., as the essence of this invention does not reside in the tackifying temperature of the adhesive used on the seaming tape. The maximum temperature is determined largely by the type of carpet backing on which the tape is to be applied. After the heating means is sufficiently heated, it is moved forward under the seaming tape. As the heating means proceeds, the forward portion of the seaming tape, i.e. that part of the seaming tape which extends in front of the heater, is progressively brought into position between the top surface of the heater body and the carpet backing so that it may be heated to a tacky condition. Concurrently, as the heating means proceeds, portions of the tape trail off the rear end of the heater body with its adhesive in a tacky condition. The carpet segments are placed into abutment either on the heating means or behind the heating means as it passes and are pressed into the tacky adhesive. Then the adhesive at points on the tape passed by the heater body cools and solidifies, bonding the tape to the carpet backs and seaming the adjacent segments of carpeting along their abutting edges. A protective element may cover the base of the heating means to help avoid damage to floors or other surfaces which might otherwise contact the heated instrument. By the method of this invention carpet seaming is accomplished simply, cleanly, and with assuredness that strong bonding has been achieved between the tape and carpeting.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features will appear from the following description of this invention, detailed in reference to the accompanying drawings, in which:
FIG. 1 illustrates the relationship between the carpet segments, seaming tape, and one type of heating means in position for performance of one variation of the method of carpet seaming of this invention.
FIG. 2 shows a cross sectional view as taken on line 2--2 of FIG. 1.
FIG. 3 illustrates the relationship between the carpet segments, seaming tape and heating means in position for performance of another variation of the method of this invention.
FIG. 4 illustrates another type of heating means in position under the carpet segments and seaming tape for performance of the method of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The heating means utilized in the method of this invention may be any one of a number of devices which are capable of heating the adhesive by contacting the non-adhesive back side of the seaming tape under the carpet segments and of being guided along under the tape and carpeting by a person above the carpeting. One type heating means suitable for this method of carpet seaming is shown in FIGS. 1-3. That heating means is a thermal activator 1 having a heater body 2 with a flat top surface 3 and a downwardly sloping trailing top surface 4. The activator 1 includes a heat protective means 5 on the bottom surface 6 of the heater body 2. The activator 1 also includes a guiding handle 7 which is held above the heater body 2 by an attachment section 8 fastened to the side of the heater body 2. The heater body 2 is generally constructed of a heat conductive, preferably metallic, material. It may be heated electrically, with electric current being carried to a heating element within the heater body by insulated conducting wires 9, or non-electrically. Another type heating means suitable for the method of this invention is a relatively flat heater strip 10 such as shown in FIG. 4. The heater strip 10 may be flexible, being comprised of a heating element, such as an electric coil, enclosed within a heat resistant, heat conducting material, such as silicon rubber. If desired, a thermally insulating protective layer of material may cover one side of the heater strip to prevent heat damage to a surface on which the heater strip is laid.
A preferred variation of the method of carpet seaming in accordance with this invention is illustrated in FIGS. 1 and 2. This variation permits abutting carpet segments to be pressed onto the tacky adhesive of the seaming tape on the top surface of the heating means. To accomplish this, the carpet segments 11,12 to be joined are laid face-up in an adjacent arrangement on a floor or other surface on which a carpet might rest. In order that the edges of the carpet segments can be raised and placed into abutment, as shown at 13, on the top surface of the heater body, the carpet segments should first be positioned so that their edges may overlap, as shown at 14, when not raised to the height of the top surface of the heater body 2. The amount of overlapping of the carpet segments is determined by the height of the heater body, it being necessary that the edges of the carpet segments are capable of being placed into abutment along at least a portion of the top surface of the heater body. The heating means 1 is inserted between the carpet segments so that the heater body 2 is under the carpet segments to be joined and under a portion of a strip of heat activatable adhesive tape 15. The adjacent edges of the carpet segments to be joined are raised above the top surface of the heater body 2 and placed in abutment contacting at least a portion of the tape strip on the top surface of the heater body. The above-mentioned portion of the strip of heat activatable adhesive tape is positioned between the heater body and the abutting carpeting, with the carpeting on each side of the abutting edges covering and contacting approximately half the tape's adhesive coated surface. The forward portion of tape extending to the front of the heater body (to the right as shown in FIG. 1) may be laid out under the carpet sections or may extend up between the carpet sections, possibly into a tape dispensing means.
The heating means should include some type of guide means by which the heater body may be moved along under the carpeting where the sections are to be joined. When a thermal activator 1 is utilized as the heating means, a handle 7 is provided which is held above the carpeting by a handle attachment 8 extending between the carpet segments through an opening created by the raising of at least one of the carpet segments to connect to one side of the heater body.
After the above-described relationship between the floor, heating means, tape, and carpet segments has been established, the heater body 2 is heated to a temperature sufficient to bring the heat activatable adhesive 16 to a tacky condition by contacting the non-adhesive surface 17 of the tape with the heating means' trailing top surface 4 or top surface 3 for a reasonably short time. Heating of the heater body may be accomplished by closing an electric circuit directed to a heating element through insulated conducting wires 9 entering the heating means through the handle section. When the heater body has been sufficiently heated, it is gradually moved forward (to the right as viewed in FIG. 1). As the heating means proceeds, successive forward portions of tape strip are threaded into proper alignment between the heater body and the carpet segments. Each succeeding tape segment is retained between the carpet and heater body long enough to insure that that segment's adhesive coating becomes tacky. Since the carpet segments are brought into abutment above a portion of the top surface of the heater body, the carpeting can be pressed into the tacky adhesive of the tape against the surface of the heater body. Thus, the adhesive definitely exists in a tacky condition for a time while directly contacting the backing of the abutting carpet segments. When the heated activator moves past an activated segment of tape, the adhesive on that segment cools and solidifies, adhering to the backing of each of the carpet segments and seaming them together along the abutting edges. As indicated, downward pressure may be exerted on portions of the carpeting while the adhesive is in its tacky condition and the portions of the abutting carpet segments are overlying portions of the top surface in order to insure a firm connection between the tape and carpet backing. By continuing this procedure as the activator is moved along the length of the desired seam, the carpet segments become securely held together or seamed along their abutting edges. The slope of the heater body's trailing top surface 4 may permit a smooth transition of the seamed carpeting from a position above the heater body to the floor, so that the seam will not be weakened by a sudden drop.
The top surfaces of the heater body of the thermal activator provide solid support for the seaming tape, when pressure, such as hand pressure, is applied to press the carpet backing down onto the tape during performance of this variation of the seaming method. This support is especially important when the seaming operation is being performed on carpeting over a resilient or spongy pad, such as when seaming over a carpet underlay pad. In prior art methods of carpet seaming, such as the Burgess method discussed above, if pressure were applied to press the carpeting down onto the tape while lying on a resilient pad, there would be no solid backing to support the tape. The resilient pad would give way under the pressure, reducing the effectiveness of such pressure to increase the bonding between the tape and the carpet backing. With the support provided by the heater body of the activator in the present invention, however, the effectiveness of such pressure in improving the bonding between the tape and the carpet backing is substantially increased. Of course, after a firm seam has been created by this variation of the method, it may be necessary to spread the carpeting slightly to flatten it and avoid any possible bulges produced by placing in abutment and seaming along the edges which once had overlapped each other.
In instances where, due to carpet bulk or size or other reasons, it is impossible or impractical to provide for overlap of the carpet segments along the edges to be seamed before they are raised above the heater body, a variation of the method of this invention may be employed which differs slightly from the above-described procedure. This variation may be understood by reference to FIG. 3. In this variation, the heating means, seaming tape, and carpet segment are arranged in basically the same relationship with respect to each other as for the above-described procedure, that is the heater body 2 is positioned under the carpet segments 11,12 at the edges to be seamed, with the tape strip 15 resting on the top surface of the heater body with its adhesive surface directed toward the carpet backing. However, in this variation the carpet segments are placed in abutment instead of being overlapped along the edges to be joined before being placed above the top surface of the heater body. Therefore, they cannot be brought into close abutment when raised and placed above the heater body top surface. Instead, a gap 18 exists between the edges of the carpet segments when positioned above the top surface of the heater body. Occasionally the carpet segments may be stretched to close the gap, in which cases the previously described procedure may be employed to seam the carpet segments along the edges brought into abutment by stretching the carpeting. Frequently, however, such stretching of the carpeting cannot be easily accomplished. Then it is necessary to heat the adhesive 16 on the seaming tape to a tacky condition by contacting the non-adhesive surface 17 of the tape with the surface of the heater body 2 but to not allow the carpet backing to be pressed into the tacky adhesive until after the heater body has been moved out from under that tackified portion of the adhesive tape strip. When the heater body has been moved forward out from under that tackified portion of the tape strip, the carpet edges can be lowered down into abutment and pressed into the still tacky adhesive behind the trailing edge of the heater body. Then as the adhesive cools and bonds to the carpet backing the carpet segments become firmly seamed along the abutting edges.
The heater strip 10 shown in FIG. 4 may be employed as an alternative to the thermal activator as the heating means in the performance of either of the above-described variations of the method of this invention. The same basic steps as explained above are followed when performing this method with a heater strip 10, except that a person may direct the movement of the heater strip by pulling a cord, strap, wire, or other similar guide means, such as 19, attached to the heater strip and extending under the carpeting. Of course, a similar guiding means could be used with other types of heating means as well.
It is particularly noteworthy that this method may be carried out after the carpeting is positioned at its desired permanent site. Also, by this method, the danger of a messy situation resulting from exposed tacky adhesive on the heating means is eliminated. This method may be employed to perform the described operations in small areas within a home, in large areas such as assembly halls, or at other locations where carpet seaming is desired.
A person skilled in the art of this invention will recognize that there are many variations within the scope of this invention which may be used to achieve the desired objectives. This invention is intended to include all such variations, limited only to the scope defined in the following claims.