GB2217286A - A process for producing packs of small parts and packs produced by the process - Google Patents

Abstract

A process for producing stacks of small parts, for example, metal staples used to form the joints at the corners of rectangular wooden picture frames comprises providing an edge of each part with a recess located so that on stacking the parts the recesses are aligned to form a channel 16 extending along the stack, and then inserting a linear member 19 into the channel 16 with which it has interference fit to securely hold the parts together. Discrete packs are produced by severing the stack at predetermined intervals. Typically the recesses are rectangular with a width and depth of 0.75 of a millimetre and the linear member 19 is circular with a diameter of 0.80 of a millimeter. The staples are produced by coin-pressing the edge 10 of a metal strip to form a sharpened edge on the completed staples prior to press forming the v-shaped profiles of the staples, providing central rectangular recesses 14; separating the completed staples from the strip and stacking the staples (Fig 1). <IMAGE>

Description

A process for producing packs of small parts and packs produced by the process This invention relates to a process for producing packs of small parts and for producing stacks of parts from which such packs are produced. The invention also relates to stacks and packs of small parts produced by the process. A typical example of such small parts is the metal staples used to form the joints at the corners of rectangular wooden picture frames.

Hitherto such small parts, which are usually produced singly by suitable machine tool operations, are held together in packs by a lacquer or a suitable adhesive. A pack is inserted into the magazine of a manually operated or automatically operated apparatus which in the case of the metal staples mentioned above is used to drive the staples into the corners of a wooden picture frame to form the joints. A disadvantage of this previously used way of forming the packs is that the lacquer or adhesive collects in the magazine and in a relatively short time jams the mechanism so that the apparatus fails to operate. Apart from the inconvenience and possible damage to the apparatus the cleaning of the mechanism takes time so that production is lost.

An object of this invention is to provide a process for producing stacks and packs of small parts and stacks and packs of parts produced by such a process in which the above-mentioned disadvantage is alleviated.

According to the present invention a process for producing stacks of small parts comprises the steps of providing a recess in an edge of each part located so that when the parts are arranged in a stack the recesses are aligned to form a channel extending along the stack, and inserting a linear member into the channel so formed, the linear member forming an interference fit in the channel to cause the parts to be securely held together in the stack.

A recess may be provided in a plurality of edges of each part located so that when the parts are arranged in a stack the recesses are aligned to form a plurality of channels extending along respective sides of the stack, and a linear member may be inserted into each channel so formed, each linear member forming an interference fit in the associated channel to cause the parts to be securely held together in the stack.

Discrete packs of a predetermined size can then be produced by severing the stack at predetermined intervals.

preferably each recess comprises a rectangular or a U-shaped notch and the linear member is substantially circular in cross-section.

The linear member may be flexible and may be of a material which will shear cleanly and not crumble. Typically, the linear member may be of polystyrene or other suitable material.

\hen the parts are of metal the linear member may be of a metal which is soft relative to the metal of the parts. For example, when the parts are of low carbon steel the linear member may be of aluminium, brass or copper.

In one embodiment of the invention the parts are metal staples such as are used to form the joints at the corners of wooden picture frames and the metal staples are initially sharpened by a coin-pressing operation applied along one side of an edge of a strip from which the metal staples are formed. The coin-pressing operation may be carried out using carbide forming dies.

The linear member may be inserted into a channel by a roller urged against the linear member and the adjacent side of the stack containing the channel. An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which Figure 1 is a somewhat schematic diagram illustrating the process as applied to the production of metal staples for picture frames; Figure 2 is a perspective view of a metal strip during the stages of forming the metal staples; Figure 3 is a perspective view of a pack of the metal staples at a final stage of the process; and Figure 4 is a fragmentary perspective view of a corner of a wooden picture frame with one of the metal staples partly inserted.

Referring in the first instance to Figure 1, a strip 1 of low carbon steel hard rolled to Vickers diamond pyramid hardness of between 180 and 230 and wound in a coil 2 is passed through a trichlorethylene bath 3 to remove any grease. The degreased strip 1 which typically is twelve millimetres in width and 0.30 of a millimetre in thickness is fed into a specially adapted press 5 which is supported horizontally in a frame 6 so that staples 8 emerging from the press 5 are in a continuous stack 9 travelling in a horizontal direction. The tool in the press 5 is a six-stage tool that runs at three hundred strokes per minute.

As can be appreciated from Figure 2 the first stage is a coin-pressing operation 10 applied along one side of the strip 1 at one edge 11 using carbide forming dies. The second stage of the press tool moves the strip 1 along and the third stage forms a V-shaped profile 12 which will constitute the body of a staple 8 (see Figure 4). The fourth and fifth stages of the press tool form rectangular recesses 14 at intervals down the centre of the strip 1 and form the retaining fins 15 respectively. The sixth and final stage crops the completed staple 8 off the strip 1 and packs the stales 8 into a continuous stack 9 which leaves the press 5 with the coin-pressed edges 11 uppermonst and the recesses 14, which are located in the edges of the cropped staples 8, aligned to form channels 16 along two opposite sides of the stack 9.A device in the last stage of the press tool acts to stop a staple 8 from coming back out of the top of the die since considerable back pressure is exerted by the stack 9.

The stack 9 leaving the press 5 is guided by a chute which has been omitted from Figure 1 to simplify the drawing and which is arranged so that the stack 9 travels between a pair of spring loaded rollers 17 which are urged against the two opposite sides of the stack 9 in which the channels 16 are formed.

Two linear members 19 each wound on a reel 20 are fed into the respective channels 16 by way of co-operating pulleys 21. Preferably each roller 17 is of- composite construction comprising a central section of steel which engages the linear member 19 and two outer sections of rubber which engage the side of the stack 9 and cause the roller 17 to rotate about a vertical axis 23 as the stack 9 moves in the direction of the arrow 24.

The rollers 17 force the linear members 19 into the channels 16 so that they form an interference fit and cause the staples 8 to be securely held together in the stack 9. With staples 8 formed from low carbon steel, a linear member 19 may be a strip or rod of a flexible plastics material such as polystyrene. Typically the recesses 14, which may be rectangular or U-shaped would have a width and depth of substantially 0.75 of a millimetre and the cross-section of the linear member 19 would be substantially circular and have a diameter of substantially 0.80 of a millimetre.

On leaving the rollers 17 the stack 9 travels towards a blade 25 located above the stack 9 and moved vertically up and down by a solenoid 27 so that the blade 25 severs the stack 9 at predetermined intervals to produce discrete packs 28 each containing a predetermined quantity of staples 8, The packs 28 then travel towards a turntable 29 on which they are deposited, the linear members 19 in the channels 16 firmly holding the staples 8 together in the packs 28. Typically, a pack 28 of staples 9 such as that depicted in Figure 3 would contain approximately one hundred and twenty-five staples 8 and would measure six centimetres in length and twelve millimetres in width and height.However, the staples from which packs 28 are formed may have various sizes and may be any size between four and sixteen millimetres in one millimetre increments in vertical height as seen in Figure 3 and may include imperial sizes.

The packs 28 of staples 8 produced by the process of the invention have a marked and important advantage over the packs held together by lacquers or adhesives as previously proposed. whereas the lacquers and adhesives tend to clog and jam the mechanisms of the magazines in which the packs are inserted, the small portions of the linear members 19 are retained within the recesses 14 when the staples are separated by the magazine and inserted in a picture frame 30 as shown in Figure 4.

Although the staples 8 described above are small parts made of metal it will be appreciated that small parts made of plastics material or other suitable materials may be held securely together in stacks 9 and packs 28 by the linear members 19 inserted in channels 16 as described above, provided that the material of the linear member is chosen to suit the material of the small parts concerned. Generally the material of the linear members must be strong enough to hold the parts together and yet will shear and not crumble where the parts need to be separated.. Although linear members 19 of a plastics material such as polystyrene heove been described above metals such as aluminium, brass and copper may be used when the parts are of steel or other relatively hard materials. Moreover, itis not essential that two linear members 19 should be used as described for the metal staples 8 and a single linear member may suffice for other small parts depending on the shape of the parts concerned.

Claims (16)

CLAITE

1. A process for producing stacks of small parts comprising the steps of providing a recess in an edge of each part located so that when the parts are arranged in a stack the recesses are aligned to form a channel extending along the stack, and inserting a linear member into the channel so formed, the linear member forming an interference fit in the channel to cause the parts to be securely held together in the stack.

2. A process as claimed in Claim 1, wherein a recess is provided in a plurality of edges of each part located so that when the parts are arranged in a stack the recesses are aligned to form a plurality of channels extending along respective sides of the stack, and a linear member is inserted into each channel so formed, each linear member forming an interference fit in the associated channel to cause the parts to be securely held together in the stack.

3. A process as claimed in Claim 1 or Claim 2, wherein the stack is severed at predetermined intervals to produce discrete packs of a predetermined size.

4. A process as claimed in any preceding claim, wherein each recess comprises a rectangular or a U-shaped notch and the linear member is substantially circular in cross-section.

5. A process as claimed in any preceding claim, wherein the linear member is flexible and is of a material which will shear cleanly and not crumble.

6. A process as claimed in any preceding claim, wherein the linear member is of polystyrene or other suitable plastics material.

7. A process as claimed in any one of Claims 1 to 5, wherein the parts are of metal and the linear member is of a metal which is soft relative to the metal of the parts.

8. A process as claimed in Claim 7, wherein the parts are of low carbon steel and the linear member is of aluminium, brass or copper.

9. A process as claimed in any preceding claim, wherein the parts are metal staples such as are used to form the joints at the corners of wooden picture frames.

10. A process as claimed in Claim 9, wherein the metal staples are initially sharpened by a coin-pressing operation applied along one side of a strip along one edge.

11. A process as claimed in Claim 10, wherein the coin-pressing operation is carried out using carbide forming dies.

12. A process as claimed in any preceding claim, wherein a linear member is inserted into a channel by a roller urged against the linear member and the adjacent side of the stack containing the channel.

13. A stack of small parts held together by the process claimed in any preceding claim.

14. A pack of small parts severed from a stock of small parts as claimed in Claim 13.

15. A process for producing stacks and packs of small parts substantially as herebefore described with reference to the accompanying drawings.

16. A stack or a pack of staples produced by a process substantially as hereinbefore described with reference to the accompanying drawings.

16. A stack or a pack of small parts produced by a process substantially as hereinbefore described with reference to the accompanying drawings.

Amendments to the claims have been filed as follows 1. A process for producing stacks of staples from a metal strip, comprising coin pressing one side of the strip at one edge to sharpen that edge, pressing the strip to form a succession of V-shaped profiles each of which will constitute the body of a staple1 forming recesses at predetermined intervals along the strip, cropping the V-shaped profiles off the strip and arranging them in a continuous stack with the recesses aligned to form a channel extending along the stack, and inserting a linear member into the channel so formed, the linear member forming an interference fit in the channel to cause the staples to be securely held together in the stack.

2. A process as claimed in Claim 1, wherein a recess is provided in a plurality of edges of each V-shaped profile so that when the profiles are arranged in the stack the recesses are aligned to form a plurality of channels extending along respective sides of the stack, and a linear member is inserted into each channel so formed, each linear member forming an interference fit in the associated channel to cause the staples to be securely held together in the stack.

3. A process as claimed in Claim 1 or Claim 2, wherein the recesses are formed in fins provided at the extremities of the V-shaped profiles..

4. A process as claimed in any preceding claim, wherein the stack is severed at predetermined intervals to produce discrete packs of a predetermined size.

5. A process as claimed in any preceding claim, wherein each recess comprises a rectangular or a U-shaped notch and the linear member is substantially circular in cross-section.

6. A process as claimed in any preceding claim, wherein the linear member is flexible and is of a material which will shear cleanly and not crumble.

7. A process as claimed in any preceding claim, wherein the linear member is of polystyrene or other suitable plastics material.

8. A process as claimed in any one of Claims 1 to 6, wherein the linear member is of a metal which is soft relative to the metal of the strip.

9. A process as claimed in Claim 8, wherein the strip is of low carbon steel and the linear member is of aluminium, brass or copper.

10. A process as claimed in any preceding claim, wherein the staples are those used to form the joints at the corners of wooden picture frames.

11. A process as claimed in any preceding claim, wherein the coin pressing is carried out using carbide forming dies.

12. A process as claimed in any preceding claim, wherein a linear member is inserted into a channel by a roller urged against the linear member and the adjacent side of the stack containing the channel.

13. A stack of staples held together by the process claimed in any preceding claim.

14. A pack of staples severed from a stack as claimed in claim 13.

15. A process for producing stacks and packs of staples substantially as hereinbefore described with reference to the accompanying drawings.