TURNING KEY FOR ROLLING-UP THE EMPTY END OF A TUBE, POSSIBLY IN COMBINATION WITH A SQUEEZING DEVICE
United States Patent 3759421
A turning key for rolling up the empty end of a tube includes a handle and an integrally formed shaft. The shaft has a slit defined by its thin radially elastic walls. There is an opening at the end of the slit nearest the handle to accommodate the edge of the tube. The slit readily grasps an empty tube because it is normally closed.
US Patent References:
Adapter for collapsible tube winding key for varying taper of key
Krueger - November 1950 - 2531060
Adapter for collapsible tube winding key for varying taper of key
Krueger - November 1950 - 2531060
Application Number:
05/187026
Publication Date:
09/18/1973
Filing Date:
10/06/1971
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Export Citation:
Primary Class:
International Classes:
B65D35/32; B65D35/24; B67D3/00
Field of Search:
222/97-103,96 242/85,96
Primary Examiner:
Coleman, Samuel F.
Assistant Examiner:
Martin L.
Claims:
I claim
1. A turning key for rolling up the empty end of a tube comprising a handle, a thin-walled radially elastic shaft intergrally formed with and extending from the handle, the walls of the shaft at the end nearest the handle increasing in thickness in the direction of the handle, a slit extending axially along the shaft and normally closed along the greater part of its length, and an opening formed at the end of the slit nearest the handle.
2. The turning key of claim 1, wherein the slit defines a V-shaped entrance at the end farthest from the handle.
3. The turning key of claim 1, wherein the exterior surface of the shaft is cylindrical.
4. The turning key of claim 1, further comprising a cylindrical bore defined by the shaft which is concentric with the exterior surface of the shaft, and a recess formed in the wall of the shaft opposite the opening.
1. A turning key for rolling up the empty end of a tube comprising a handle, a thin-walled radially elastic shaft intergrally formed with and extending from the handle, the walls of the shaft at the end nearest the handle increasing in thickness in the direction of the handle, a slit extending axially along the shaft and normally closed along the greater part of its length, and an opening formed at the end of the slit nearest the handle.
2. The turning key of claim 1, wherein the slit defines a V-shaped entrance at the end farthest from the handle.
3. The turning key of claim 1, wherein the exterior surface of the shaft is cylindrical.
4. The turning key of claim 1, further comprising a cylindrical bore defined by the shaft which is concentric with the exterior surface of the shaft, and a recess formed in the wall of the shaft opposite the opening.
Description:
This invention concerns a turning key for squeezing or for rolling up the emptied end of a spreader tube.
Turning keys such as known, often show a longitudinal slit all along the shaft. If this slit is open at the end opposite to the handle of the key it is easy to insert the end of the tubeinto the shaft, but the shaft, split by the slit, becomes too weak to transmit the turning motion from the handle to the tube. This type of key has been stiffened by using a head piece to hold the free ends of the shaft together. There are also turning keys known with a hollow cylindrical shaft axially slit on one side. This kind of shaft, while being torsion-proof, has the disadvantage that it is not able to catch the end of the tube. This makes it impossible to insert the end of the full tube into the squeezing device. The key gets a hold on the tube when at least so much of the tube only is empty that a half turn of the key can be rolled up on the key shaft. Of course, it is possible to use the tube in the beginning without the squeezing device and to thread it later on into the slit of the key shaft and into the squeezing device, but this is considered a disadvantage.
SUMMARY OF THE INVENTION
The invention's aim is to create a turning key which does not have these disadvantages. According to the invention the turning key has a hollow-cylindrical shaft, axially slit at one side and a handle rigidly connected with the shaft. It is, in particular, constructed in a way that the shaft is radially elastic so that the axial slit in the shaft is able to clamp on the tube's end which is inserted into it.
It may be thought that such a shaft, which naturally is relatively thin-walled, in order to be elastic, would twist when rolling up the tube. It is the merit of the inventor to have (according to expert opinion) conquered this fault. It has been found that, if the right material (preferably plastic) is chosen, a key with a thin-walled shaft, due to its inherent elasticity, is less liable to break than a similar key the shaft of which is thick-walled and non-elastic. The shaft, however, must be formed in a way appropriate for the material involved. For this reason, it is of advantage to taper the end of the hollow shaft which is nearest to the handle.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawing are shown the details of the object of the invention:
FIG.1 shows a turning key in side view, in greater than actual size.
FIG.2 shows an axial section of the key, as per FIG.1 taken, along the line II--II.
FIG.3 shows a section of the key, as per FIG.1 taken along the line III--III with a plastic tube clamped into the slit.
FIG.4 shows a section, as per FIG. 3, but with a metal tube the lower end of which is clamped into the slit.
FIG.5 & 6 show the use of a key, as per FIG.1-4, where the key is inserted into a simple squeezing device which serves to squeeze out the tube and to roll it up.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The turning key shown in FIG.1-4 is made of a plastic material which has sufficient elastic qualities. In this way the key can be made in one piece and the shaft 1 consists of the same material as the handle 2. The shaft 1 is formed as a hollow cylinder with a longitudinal slit 3. On the end which is most distant from the handle the slit is open and --at 4-- widened in V-form to facilitate the insertion of the flat end of a tube. On the end nearest to the handlethe slit is --at 5-- also widened in order to prevent excessive deformation of the material where it is thicker, while retaining the radial elasticity of the shaft. The shaft 1 is radially elastic because of the choice of a suitable material and also because its walls d are relatively thin, between 0.5 and 1.5 mm. The inside diameter of the hollow shaft D is -- at 6 -- tapered on its end nearest to the handle 2 in order to effect a gradual transition from the thin-walled shaft 1, to the relatively thick handle 2. The taper has about the length of the slit-widening 5.
The width, i.e., the opening of the slit 3 when the key is not in use, is between 0 and 1 mm. The slit may be almost entirely closed.
The key, when used, is moved onto the flat end of the tube, whereby it clamps on to it. FIG. 3 shows the clamping effect on a plastic tube K the flat end of which is welded shut. FIG. 4 shows a metal tube M the end of which is closed by double welt. In this case the elastic shaft grips the thinner metal wall of the tube.
FIG. 5 and 6 show the use of the new turning key in connection with a simple squeezing device. This device consists of an Omega-shaped bent elastic strip 10 . The material of strip 10 may be plastic or metallic. This kind of device, consisting of a simple holder 10 with a key 1.2, is particularly well suitable for the squeezing of plastic tubes, because these, when squeezed by hand, tend to return to their original shape which causes them to take in air.
When a device as per FIG. 5 & 6 is used the plastic tubes cannot unroll and the complete squeezing and the neat rolling-up of the tube are assured.
An additional recess 7, placed diametrically to slit 3 in the tapered part of the shaft bore permits the use of the full width of the slit.
It is clear that the new key can also be used in a squeezing device different from the one shown here. The turning key can also be used without any such device, merely to roll up the empty end of the tube.
This way of using the turning key is only applicable to metal tubes which remain in position when rolled up and have no tendency -- like plastic tubes-- to return to their original shape.
The general tendency is toward using this article but once: the empty tube with the key, especially with key and squeezing device, are thrown away. For this reason the cost of the key must be as low as possible.
The cost of the turning key may be brought below that of the key shown in the drawings if the material of the handle is made as thin-walled as the shaft. This not only saves material, but also shortens the pressing time if the key is made of plastic. The production is still cheaper for a turning key without a distinct handle. For this the shaft only has to be formed longer than the width of the squeezed-out tubeso that one end of the shaft extends laterally from the tube and can serve as handle. For such a turning key the end of the shaft which is to serve as handle may be roughened by fluting on the outside.
It may also be possible to make the key entirely or partly of metal, e.g., with a cylindrical slitted steel shaft which may be fitted with a plastic handle.
It will be obvious to those skilled in the art that the embodiment described above is meant to be merely exemplary and that the specific structure of the apparatus is susceptible of modification and variation without departing from the spirit and scope of the invention. Therefore, the invention should not be deemed to be limited except as defined by the appended claims.
Turning keys such as known, often show a longitudinal slit all along the shaft. If this slit is open at the end opposite to the handle of the key it is easy to insert the end of the tubeinto the shaft, but the shaft, split by the slit, becomes too weak to transmit the turning motion from the handle to the tube. This type of key has been stiffened by using a head piece to hold the free ends of the shaft together. There are also turning keys known with a hollow cylindrical shaft axially slit on one side. This kind of shaft, while being torsion-proof, has the disadvantage that it is not able to catch the end of the tube. This makes it impossible to insert the end of the full tube into the squeezing device. The key gets a hold on the tube when at least so much of the tube only is empty that a half turn of the key can be rolled up on the key shaft. Of course, it is possible to use the tube in the beginning without the squeezing device and to thread it later on into the slit of the key shaft and into the squeezing device, but this is considered a disadvantage.
SUMMARY OF THE INVENTION
The invention's aim is to create a turning key which does not have these disadvantages. According to the invention the turning key has a hollow-cylindrical shaft, axially slit at one side and a handle rigidly connected with the shaft. It is, in particular, constructed in a way that the shaft is radially elastic so that the axial slit in the shaft is able to clamp on the tube's end which is inserted into it.
It may be thought that such a shaft, which naturally is relatively thin-walled, in order to be elastic, would twist when rolling up the tube. It is the merit of the inventor to have (according to expert opinion) conquered this fault. It has been found that, if the right material (preferably plastic) is chosen, a key with a thin-walled shaft, due to its inherent elasticity, is less liable to break than a similar key the shaft of which is thick-walled and non-elastic. The shaft, however, must be formed in a way appropriate for the material involved. For this reason, it is of advantage to taper the end of the hollow shaft which is nearest to the handle.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawing are shown the details of the object of the invention:
FIG.1 shows a turning key in side view, in greater than actual size.
FIG.2 shows an axial section of the key, as per FIG.1 taken, along the line II--II.
FIG.3 shows a section of the key, as per FIG.1 taken along the line III--III with a plastic tube clamped into the slit.
FIG.4 shows a section, as per FIG. 3, but with a metal tube the lower end of which is clamped into the slit.
FIG.5 & 6 show the use of a key, as per FIG.1-4, where the key is inserted into a simple squeezing device which serves to squeeze out the tube and to roll it up.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The turning key shown in FIG.1-4 is made of a plastic material which has sufficient elastic qualities. In this way the key can be made in one piece and the shaft 1 consists of the same material as the handle 2. The shaft 1 is formed as a hollow cylinder with a longitudinal slit 3. On the end which is most distant from the handle the slit is open and --at 4-- widened in V-form to facilitate the insertion of the flat end of a tube. On the end nearest to the handlethe slit is --at 5-- also widened in order to prevent excessive deformation of the material where it is thicker, while retaining the radial elasticity of the shaft. The shaft 1 is radially elastic because of the choice of a suitable material and also because its walls d are relatively thin, between 0.5 and 1.5 mm. The inside diameter of the hollow shaft D is -- at 6 -- tapered on its end nearest to the handle 2 in order to effect a gradual transition from the thin-walled shaft 1, to the relatively thick handle 2. The taper has about the length of the slit-widening 5.
The width, i.e., the opening of the slit 3 when the key is not in use, is between 0 and 1 mm. The slit may be almost entirely closed.
The key, when used, is moved onto the flat end of the tube, whereby it clamps on to it. FIG. 3 shows the clamping effect on a plastic tube K the flat end of which is welded shut. FIG. 4 shows a metal tube M the end of which is closed by double welt. In this case the elastic shaft grips the thinner metal wall of the tube.
FIG. 5 and 6 show the use of the new turning key in connection with a simple squeezing device. This device consists of an Omega-shaped bent elastic strip 10 . The material of strip 10 may be plastic or metallic. This kind of device, consisting of a simple holder 10 with a key 1.2, is particularly well suitable for the squeezing of plastic tubes, because these, when squeezed by hand, tend to return to their original shape which causes them to take in air.
When a device as per FIG. 5 & 6 is used the plastic tubes cannot unroll and the complete squeezing and the neat rolling-up of the tube are assured.
An additional recess 7, placed diametrically to slit 3 in the tapered part of the shaft bore permits the use of the full width of the slit.
It is clear that the new key can also be used in a squeezing device different from the one shown here. The turning key can also be used without any such device, merely to roll up the empty end of the tube.
This way of using the turning key is only applicable to metal tubes which remain in position when rolled up and have no tendency -- like plastic tubes-- to return to their original shape.
The general tendency is toward using this article but once: the empty tube with the key, especially with key and squeezing device, are thrown away. For this reason the cost of the key must be as low as possible.
The cost of the turning key may be brought below that of the key shown in the drawings if the material of the handle is made as thin-walled as the shaft. This not only saves material, but also shortens the pressing time if the key is made of plastic. The production is still cheaper for a turning key without a distinct handle. For this the shaft only has to be formed longer than the width of the squeezed-out tubeso that one end of the shaft extends laterally from the tube and can serve as handle. For such a turning key the end of the shaft which is to serve as handle may be roughened by fluting on the outside.
It may also be possible to make the key entirely or partly of metal, e.g., with a cylindrical slitted steel shaft which may be fitted with a plastic handle.
It will be obvious to those skilled in the art that the embodiment described above is meant to be merely exemplary and that the specific structure of the apparatus is susceptible of modification and variation without departing from the spirit and scope of the invention. Therefore, the invention should not be deemed to be limited except as defined by the appended claims.