Title:
DOOR KNOB RETAINING APPARATUS
United States Patent 3695664


Abstract:
Door knob retaining apparatus comprised of a spring loaded member adapted for movement within a rosette assembly of a door latch unit. The spring loaded member is urged to a first axial position so as to prevent the release of a door knob engaging finger and is adapted to be moved to and retained at a second axial position to allow the release of the door knob engaging finger. Using this door knob retaining apparatus, an outside door knob may not be released and removed from the outside, but may be readily released and removed from the inside by using a special tool for this purpose.



Inventors:
NOLIN ROGER J
Application Number:
05/104685
Publication Date:
10/03/1972
Filing Date:
01/07/1971
Assignee:
TOOL RESEARCH & ENG.
Primary Class:
International Classes:
E05B3/00; (IPC1-7): E05B3/00
Field of Search:
292/352,353,354,348,169
View Patent Images:
US Patent References:
3337254Handhold retainer block1967-08-22Russell
3232653Plastic door lock assembly1966-02-01Wilson
3228218Lock set assembly1966-01-11Wilson
3212306Combination hand-hold retainer and key-operated mechanism retainer1965-10-19Russell



Primary Examiner:
Wolfe, Robert L.
Claims:
I claim

1. Door knob retention apparatus comprised of a spring loaded member and a rosette assembly;

2. The door knob retention apparatus of claim 1 wherein said spring loaded member has an inclined surface disposed to engage a surface of said knob retaining member and to progressively urge said knob retaining member from said second retaining member position to said first retaining member position as said spring loaded member moves from said second axial position to said first axial position.

3. The door knob retention apparatus of claim 2 wherein said spring loaded member has an axially disposed hole therethrough;

4. The door knob retention apparatus of claim 3 wherein said spring loaded member is urged toward said knob by a coil spring acting in compression;

5. Door knob retention apparatus comprised of a door knob, and a mating member extending from a rosette assembly;

6. The door knob retention apparatus of claim 5 wherein said spring loaded member has an inclined surface disposed to engage a surface of said knob retaining member and to progressively urge said knob retaining member from said second retaining member position to said first retaining member position as said spring loaded member moves from said second axial position to said first axial position.

7. The door knob retention apparatus of claim 5 wherein said spring loaded member is urged in said first axial direction by a coil spring acting in compression;

8. The door knob retention apparatus of claim 7 wherein said spring loaded member has an axially disposed hole therethrough;

9. Door knob retention apparatus comprised of a door knob and a substantially cylindrical mating member attached to a door latch mechanism and defining an axis;

10. The door knob apparatus of claim 9 wherein said spring loaded member has an inclined surface disposed to engage a surface of said knob retaining member and to progressively urge said knob retaining member from said second retaining member position to said first retaining member position as said spring loaded member moves from said second axial position to said first axial position.

11. The door knob retention apparatus of claim 10 wherein said spring loaded member is urged in said first axial direction by a coil spring acting in compression;

12. The door knob retention apparatus of claim 11 wherein said spring loaded member has an axially disposed hole therethrough;

13. A member for use in a door latch mechanism, as part of a means for locking a door knob thereto;

14. The member of claim 13 wherein said member has an axially disposed hole therethrough.

Description:
BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of door latches.

2. Prior Art

External door knobs that may be removed from the latch mechanism are a popular subject for theft and vandalism. This is particularly true during the construction phase of a building having multiple installations, such as apartment houses and motels. Consequently, it has long been the practice in the prior art to permanently attach the outer door knob to the door latch mechanism, so as to eliminate, or at least substantially reduce, the theft and vandalism encountered. This is generally achieved by machine staking the neck of the handle to the main part of the latch mechanism, which makes removal of the knob impossible without damaging the knob or other parts of the mechanism.

The permanent staking of one knob to the door latch mechanism achieves the desired end result. However, though the staking operation is a relatively simple operation, it does involve significant tooling and the use of special equipment for this purpose. Normally a manufacturer of such door latch apparatus has sufficient staking equipment to stake the knobs in place at a rate equal to the production rate of door latches by that manufacturer. However, the general nature of the business is such that large orders for latches having a specific combination of knobs and rosettes must be delivered very shortly after the order is received, if the manufacturer is to provide the delivery service that builders and other customers expect. Consequently, a manufacturer must have staking equipment for staking the door knob to the rest of the door latch apparatus at a rate which is many times greater than the average production rate for that manufacturer so that sub-assemblies may be quickly completed upon receipt of an order, or a large inventory of completed door latches with all combinations of knobs and rosettes must be maintained at all times. Such inventories allow the delivery of finished door latches directly from stock immediately upon receipt of an order and, therefore, from the customers point of view, is the more desirable approach to the problem. However, because of the number of different types and finishes of knobs and rosettes, and the possible combinations of inner and outer knobs that a manufacturer must offer in order to be considered as having a complete line of such products, an inventory of sufficient numbers of each of these combinations represents a large and basically unproductive investment of capital in the way of finished goods. Furthermore, the finished assemblies are bulky and easily damaged, and therefore, must be carefully and independently placed in storage trays specially designed for this purpose.

In the event a door knob on one of these staked assemblies is damaged, the door knob may not be easily removed and replaced, but instead the entire latch mechanism attached to the knob is at least temporarily unsuitable for shipment until the knob is forceably removed and a new knob staked in place. This accentuates the handling problem of the finished assemblies since the damage to a knob or a rosette on a finished assembly represents a much bigger loss than similar damage to unassembled parts.

In addition to the above, the permanent assembly of a knob with the rest of the door latch mechanism involves additional handling and expense. For instance, inventories of combinations of knobs and rosettes are maintained based on anticipated demands for each combination. If a demand is underestimated, immediate delivery will be impossible. On the other hand, if a demand is overestimated, considerable money and space will be tied up in an inactive inventory.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to a door knob retaining apparatus comprised of a spring loaded member adapted for axial and rotational movement within a rosette assembly of a door latch unit. The spring loaded member is urged by the spring to an axial position so as to prevent the release of a door knob engaging finger. The spring loaded member has a hole therethrough by which the member may be engaged by a special tool from the opposite side of the door. When so engaged, it may be withdrawn against the spring force and rotated to lock the member at the withdrawn axial position, so that the door knob retaining finger may be depressed and the door knob removed. The spring loaded member is provided with a concentric screwdriver engaging surface on the inner end thereof so that it may be readily rotated to an angular orientation allowing its axial movement to the locked position by a screwdriver inserted through the other side of the door knob assembly. Using this door knob retaining apparatus, an outside door knob may not be released and removed from the outside, but may be readily released and removed from the inside by using a special tool for this purpose.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a pair of rosette assemblies with door knobs attached thereto as they are normally assembled on a door.

FIG. 2 is a side view of one of the rosette assemblies and door knobs of FIG. 1 shown in partial cross-section.

FIG. 3 is a perspective view showing the details of one end of the spring loaded member in the door knob retaining apparatus.

FIG. 3a is a perspective view of the spring loaded member of FIG. 3 showing the details of the other end of the spring loaded member.

FIG. 4 is a further cross-section of the rosette assembly of FIG. 2 on a slightly expanded scale showing the location and the manner of actuation of the spring loaded member to achieve the results of the present invention.

FIG. 5 is a cross-section of the rosette assembly of FIG. 2 also on an expanded scale showing the spring loed member in the withdrawn position so that the door knob may be removed.

FIG. 6 is a partial cross-section of the rosette assembly of FIG. 4 taken along lines 6--6 of that figure.

FIG. 7 is a pal cross-section of the rosette assembly of FIG. 4 taken along lines 7--7 of that figure.

FIG. 8 is a partial cross-section of the rosette assembly of FIG. 4 taken along lines 8--8 of that figure.

FIG. 9 is a perspective view of the spring loaded member and the spring loaded finger.

FIG. 10 is a perspective view of the spring urging the spring loaded finger into engagement with the door knob.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is a door knob retention apparatus which prevents the removal of a door knob from a door latch apparatus unless access is available from the opposite side of the door (the word knob as used herein is used in general sense to refer to a hand hold for a door latch mechanism, which may include not only knobs defining a surface of revolution, but also other types of hand holds such as levers and the like). This apparatus is intended for use primarily in outer doors of such installations as apartment houses and motels where a knob removable from the outside would be a likely target of vandalism and theft. The door knob retention apparatus of the present invention prevents the removal of a door knob from the door latch mechanism from that side of the door, but allows the easy removal of that knob provided one has access to the other side of the door (typically the inside of an apartment house door or of a motel door).

The present invention door knob retention apparatus is intended for use with a door latch mechanism which is separate and apart from the door lock. Thus, in these installations, a dead bolt and pin tumbler lock is located on the door above or below the door latch mechanism within which the present invention is used.

Now referring to FIG. 1, a top view of a typical door latch mechanism which may use the present invention door knob retention apparatus may be seen. Door knob 20 has a neck portion 22 which slips over a mating cylindrical member extending from the rosette assembly 37, located generally under rosette 24, and is retained on the cylindrical member by spring loaded finger 26, which engages a mating opening in the neck 22 of knob 20 when the knob is placed in position on the rosette assembly. Similarly, the neck 28 of knob 30 slides over a mating cylindrical member extending from a portion of the latch mechanism 36 under rosette 32, and is locked in position on the cylindrical member by spring loaded finger 34.

In a typical internal installation, that is, in an installation between rooms within a building, the knobs would not be staked in place, but would be readily removable by the depression of spring loaded fingers 26 and 34 so as to allow the knob to slip axially off the mating cylindrical members. For purposes of installation, knob 30 would be removed from the portion of the latch mechanism 36 located under rosette 32 and similarly, rosette 32, which normally snaps in position on the mechanism 36, would also be removed. This allows access to the head of mounting screws 38, which engage mating threaded members 40 extending from the rosette assembly located on the other side of the door. Thus, for mounting the mechanism to the door, door knob 20 and its attached mechanism is placed on one side of the door in a hole therethrough, so that drive member 41 or members attached thereto, which are well known in the prior art, engage a latch which has been inserted through a cooperatively disposed hole in the edge of the door. The mechanism 36 is placed on the opposite side of the door and is attached to the mechanism of door knob 20 by means of attachment screws 38. Thereafter, rosette 32 is snapped in place, finger 34 is depressed and door knob 30 is positioned axially along mating cylindrical member of mechanism 36 until spring loaded finger 34 snaps radially outward through the opening in the neck 28 of the knob 30 provided for that purpose.

From the above description, it may be seen that the door latch apparatus may be mounted to or removed from a door upon the removal of only one door knob, mainly the knob 30 as shown in FIG. 1, and the other knob, knob 20, may be permanently attached to the mating rosette assembly. In outside installations wherein the knob 20 would be on the outside of a door such as the main door to an apartment in an apartment house, it is common practice to stake that knob to the mating rosette assembly at the time of manufacture, either in addition to or in lieu of the retention provided by spring loaded member 26. Thus, by doing this, the outside knob may not be removed nor the door latch mechanism disassembled and removed from the door without having access to the other side of the door. (e.g., the inside of the apartment) The present invention door knob retention apparatus is an apparatus for locking spring loaded finger 26 in its extended position, that is, in the position for locking door knob 20 onto the mating rosette assembly. This locking apparatus may be actuated by a tool passed through the center of the door latch mechanism from the opposite side of the door. Thus, with the present invention, door knob 20 may not be removed unless one has access to the other side of the door, but having such access, or having the rosette assemblies off the door, the knob may be readily removed should such removal be desired.

Now referring to FIG. 2, a partial cross-section of a knob and rosette assembly using the present invention may be seen. In this FIGURE, the door knob 20 is shown in cross-section and the cylindrical member 44 extending axially outward from the rosette assembly 37 may be seen. The cylindrical member 44 has a longitudinal slot diametrically opposite finger 34, as may be best seen in FIGS. 7 and 8. The door knob 20 contains a dimple 46 on the neck of the knob diametrically opposite the opening for spring loaded finger 26 and thus the dimple 46, in addition to the spring loaded finger 26, transmits the torque from the door knob to the cylindrical member 44 to operate the latch mechanism. The cylindrical member 44 is axially retained with respect to the mechanism 37 by raised areas 48 (FIG. 2) on one side of the mechanism 37 and by a spring clip 50 and plate 52 at the other side of mechanism 37 (FIG. 6). Plate 52 passes over the inner end of cylindrical member 44 and is retained thereon by passing end 54 of spring clip 50 through a slot in cylindrical member 44 for that purpose, and engaging the free ends 56 of spring clip 50 in notches for this purpose at the bottom of a slot in the cylindrical member 44. The cylindrical member 44 is rotationally coupled to the mechanism 37 by a finger 58 (FIG. 5) extending into the longitudinal slot in cylindrical member 44. The mechanism 37 is comprised of a spring mechanism which allows rotation in either direction, but which elastically encourages the mechanism to a center or neutral position. These elements are well known to the prior art, but have been briefly described herein so that the function and cooperation of the invented door knob retention apparatus in the prior art door latch may be better understood.

Also shown in FIG. 2 is one of the guide fingers 60 in an elongated slot 62 in the cylindrical member 44. The guide finger 60 is integral with the spring loaded finger 26 as may be seen in FIGS. 8 and 9. The depression of the spring loaded finger 26 moves the guide finger 60 downward in the elongated slot 62, thereby serving as a guide and as a stop to limit the motion of the spring loaded finger. The spring return for the spring loaded finger 26 is provided by means of spring 64 shown in FIG. 8 and in perspective in FIG. 10. The spring 64 is in the shape of a circular arc and contains an arc shaped cutout 66 which is slightly wider than the thickness of the body of spring loaded finger 26. Thus, the spring 64 may straddle the body of spring loaded finger 26, with the bridge 68 of spring 64 resting in the notch 70 (FIG. 9) in the body of spring loaded finger 26, as shown in the assembly of FIG. 8.

Also visible in FIG. 2 is a portion 76 of end plate 72, which is better illustrated in FIG. 7. There the finger 74 of the end plate 72 may be seen. This finger engages the mating slot in the cylindrical member 44 and the two fingers 76 also rest in mating slots of cylindrical member 44, as may be best seen in FIG. 2. The end plate 72 has a square hole therethrough coaxial with cylindrical member 44. The end plate 72 is also part of the prior art, and is used to reinforce cylindrical member 44 so that it may not collapse when subjected to abusive loads (cylindrical member 44 has a longitudinal slot 45, as may be seen in FIG. 8, which would tend to allow the cylindrical member 44 to deform and/or collapse under high loads if not held at its desired diameter by end plate 72.) As will be shown, end plate 72 cooperates with the apparatus of the present invention and, therefore, it is used with the door knob retention apparatus.

Having now described the various prior art members of the door latch assembly which cooperate with the apparatus of the present invention, the additional parts for the invented apparatus shall now be described. The spring loaded member 80 may be seen in FIG. 2 extending axially outward through the hole in end plate 72 (see also FIG. 7). This spring loaded member is shown in perspective in FIGS. 3 and 3a. The member 80 is characterized by a circular portion 82 adjacent one end, an intermediate portion 84 having a taped surface 86 thereon, and an elongated portion 88 extending to the other end. The elongated portion 88 has a raised area 90 defining an end surface 92 and has two additional coplanar end aces 94, which may be best seen in FIG. 7, defined by a change in cross-section of the elongated member 88. The elongated member 88 also has a central hole 96 therethrough and the end adjacent the circular portion 82 is defined by a conical protrusion 98 having slots 100 therein adapted for engagement by an ordinary screw driver or a Phillips screwdriver.

Now referring to FIG. 7, it may be seen that when spring loaded member 80 is in the angular position as shown in that FIGURE, the end surfaces 92 and 94 are aligned with the slot between fingers 76 and the corner relief areas 102 on end member 72. Thus, spring loaded member 80 will be urged by spring 104 to the axial position shown in FIG. 4. In this position, the tapered surface 86 of the spring loaded member 80 engages the body of the spring loaded finger 26, thereby retaining the spring loaded finger 26 in the extended position, and preventing the removal of knob 20 unless one has access to the opposite of the rosette assembly. However, having such access, a tool may be inserted through the center of the rosette assembly and through the central hole 96 to hook over the door knob end of the spring loaded member so that it may bewithdrawn. Such a tool is shown in FIG. 4, having a handle 106, and an elongated member 108 and a hook 110 on the end thereof, for passage through and hooking over the end of spring loaded member 80. By then withdrawing the tool, the spring loaded member 80 may be retracted so as to allow depression of the spring loaded finger 26 and removal of the knob 20 as shown in FIG. 5. When the spring loaded member 80 is withdrawn to the position shown in FIG. 5, the end surfaces 92 and 94 are withdrawn from the appropriate openings in end plate 72, so that the spring loaded member may be locked at the withdrawn position by rotating the spring loaded member 80, by rotation of the tool, so that the end surfaces 92 and 94 no longer align with the appropriate clearance opening in the end plate 72. When so withdrawn and locked, a door knob may be readily put on or taken off the rosette assembly in the conventional manner. To lock a door knob, once put on, a small screw driver may be inserted in place of the tool shown in FIGS. 4 and 5 and engaged in the slots 100 in the conical protrusion 98. By rotating the screw driver the end surfaces 92 and 94 may be made to align with the appropriate clearances in the end plate 72, thereby allowing the spring 104 to snap the spring loaded member 80 to the position shown in FIG. 4 to lock the knob in position on the cylindrical member 44.

It is thus possible to lock a door knob onto a rosette assembly, using the present invention, with a conventional screwdriver. Consequently, assemblies of knobs, rosettes and rosette assemblies may be quickly and easily put together without substantial tooling once an order specifying the specific combination required is received. This allows the convenient and easy storage of separate knobs, rosettes and rosette assemblies, and the last minute quick assembly of such parts to satisfy a customers order. It also allows a substantial reduction in inventory, since the specific combination a customer desires may be quickly made up rather than having to stock each combination separately. By way of example, 256 combinations may be made up from a stock of only four styles of rosettes and four styles of knobs each style having four different finishes.

The detailed description of the preferred embodiment of the present invention has been presented in relation to a specific prior art door latch mechanism, and it is to be understood that modifications and variations thereof may be made by one skilled in the art for adaptation to the present invention to door latch mechanisms of other designs without departing from the scope and spirit of the present invention.