APPARATUS FOR POSITIONING SLIT CHAIN BUSHES
United States Patent 3583153
A strip of material is punched at intervals, slit into lengths through the apertures, and formed into cylindrical apertured bushes. The bushes are mounted on a conveyor having pins with spring-loaded catches, are mechanically rotated until the catches engage the apertures to locate the seams in face-to-face relationship, and are press fitted to backing plates. This enables manufacture of a chain wherein all the link bushes have optimum bearing characteristics.
US Patent References:
Composite article
Lauenstein - January 1938 - 2105048
LINK CHAIN AND METHOD OF MAKING SAME
Onulak - February 1969 - 3426522
Composite article
Lauenstein - January 1938 - 2105048
LINK CHAIN AND METHOD OF MAKING SAME
Onulak - February 1969 - 3426522
Application Number:
04/800175
Publication Date:
06/08/1971
Filing Date:
02/18/1969
View Patent Images:
Export Citation:
Assignee:
Massey-ferguson G. M. B. H. (Kassel, DT)
Primary Class:
Other Classes:
59/8, 59/35.100, 474/231
International Classes:
B21L9/00; B21L9/02
Field of Search:
59/1,468,12,13,15,35 74/250
Primary Examiner:
Lanham, Charles W.
Assistant Examiner:
Crosby, Gene P.
Claims:
I claim
1. Apparatus for assembling a roller chain link having a backing plate and first and second seamed cylindrical bushes with circular apertures diametrically disposed through the seams thereof, said apparatus including a base, a table rotatably mounted on the base, pairs of first and second spaced-apart locating pins upstanding from said table and on which the bushes are sliding fits, the pins of each pair having face-to-face aligned spring-loaded catches for engagement with the apertures in the bushes, and a brake mounted on the base for bearing against the outer surfaces of the bushes to rotate the bushes relative to the backing plate until the catches engage with the apertures.
2. Apparatus as claimed in claim 1, wherein the pins are resiliently mounted on the table.
3. Apparatus as claimed in claim 1, wherein the brake is resiliently mounted on the base.
4. A method of manufacturing roller chain links each of which includes a backing plate and first and second cylindrical seamed bushes, said method including the steps of providing a circular aperture in each bush diametrically through the seam thereof, mounting the backing plate on a template, positioning the bushes in spaced-apart relationship on the template for press fitting to the backing plate, mechanically rotating each bush until the apertures therein are substantially in face-to-face alignment with each other, and thereafter press fitting each bush to the braking plate.
1. Apparatus for assembling a roller chain link having a backing plate and first and second seamed cylindrical bushes with circular apertures diametrically disposed through the seams thereof, said apparatus including a base, a table rotatably mounted on the base, pairs of first and second spaced-apart locating pins upstanding from said table and on which the bushes are sliding fits, the pins of each pair having face-to-face aligned spring-loaded catches for engagement with the apertures in the bushes, and a brake mounted on the base for bearing against the outer surfaces of the bushes to rotate the bushes relative to the backing plate until the catches engage with the apertures.
2. Apparatus as claimed in claim 1, wherein the pins are resiliently mounted on the table.
3. Apparatus as claimed in claim 1, wherein the brake is resiliently mounted on the base.
4. A method of manufacturing roller chain links each of which includes a backing plate and first and second cylindrical seamed bushes, said method including the steps of providing a circular aperture in each bush diametrically through the seam thereof, mounting the backing plate on a template, positioning the bushes in spaced-apart relationship on the template for press fitting to the backing plate, mechanically rotating each bush until the apertures therein are substantially in face-to-face alignment with each other, and thereafter press fitting each bush to the braking plate.
Description:
This invention relates to roller chains.
Hitherto in the manufacture of roller chain links comprising two identical bushes press fitted to a backing or mounting plate in spaced-apart relationship, the bushes have been manufactured from a continuous strip of metal without waste of the material. The metal strip has been guided into the bush-forming machine by a reel and gripping tongs, and straightened and cut into short lengths as required. These short lengths have thereafter been pressed into the basic bush shape around a former and then pulled through a die so as to calibrate both the inside and the outside measurements of the bush. In this manner cylindrical bushes have been formed having a narrow slit or seam where the two edges of the flat metal have been abutted.
Links for use in roller chains, when utilizing such a bush, are known to have a short working life which, to a large extent, is due to the fact that the seams are not located in a preferred position before the bushes are press fitted to the backing plate. Thus several successive links of the chain may include bushes which have seams located in a zone of high stress and uneven wear of the chain occurs, especially in highly stressed chains such as drum chains.
An object of the present invention is to provide a method of and apparatus for manufacturing roller chain bushes as a result of which the bushes have apertures through which the seams pass.
A further object of the present invention is to provide apparatus for assembling a roller chain link, which enables precise alignment of the seams of bushes which have apertures through which the seams pass.
According to the present invention, there is provided apparatus for manufacturing bushes for a roller chain link from a strip of material, said apparatus including a strip-shearing mechanism and a bush-forming device in which cut lengths of the strip are formed into cylindrical bushes, including a punching device for punching apertures in the strip at such intervals that the shearing of the strip is effected through the apertures.
Further, according to the present invention there is provided apparatus for assembling a roller chain link having a backing plate and first and second seamed cylindrical bushes with circular apertures diametrically disposed through the seams thereof, said apparatus including a base, a table rotatably mounted on the base, and pairs of first and second spaced-apart locating pins upstanding from said table and on which the bushes are sliding fits, and the pins of each pair have face-to-face aligned spring-loaded catches for engagement with the apertures in the bushes, and a brake is mounted on the base and is adapted, when in use, to bear against the outer surfaces of the bushes to rotate same relative to the backing plate until the catches engage with the apertures.
Still further, according to the present invention there is provided a method of manufacturing roller chain links each of which includes a backing plate and first and second cylindrical seamed bushes, said method including the steps of provided a circular aperture in each bush diametrically through the seam thereof, mounting the backing plate on a template, positioning the bushes in spaced-apart relationship on the template for press fitting to the backing plate, mechanically rotating each bush until the apertures therein are substantially in face-to-face alignment with each other, and thereafter press fitting each bush to the backing plate.
Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a schematic diagram of apparatus for manufacturing roller chain bushes according to the present invention;
FIG. 1a is a plan view of the workpiece strip shown in FIG. 1;
FIG. 2 is a view, to an enlarged scale, of the hole-punching apparatus shown in FIG. 1;
FIG. 3 is a disc for aligning the seams of the bushes;
FIG. 4 is a detail of FIG. 3 shown to an enlarged scale;
FIG. 5 is a sectional view taken on the line A-B in FIG. 3, shown to an enlarged scale, of the bush alignment pin arrangement;
FIG. 6 is a modified arrangement of bush alignment pins; and
FIG. 7 is a part of a roller chain including a bush manufactured according to the present invention.
As is shown in FIG. 1, in apparatus for manufacturing bushes for roller chains, the material from which the bushes are formed is wound in a coil 10 from which a strip of material is fed through a series of spaced-apart rollers 11 so as to straighten the strip of material which thereafter successively undergoes the processes of aperture punching, shearing, and bush forming or winding.
In the aperture-punching process, the strip of material is formed over an anvil 12 and a punching tool 13, which is reciprocally slideable in a guideway 14, is automatically moved so that the tool 13 punches an aperture in the strip of material and discharges the punched material through a passage 15 in the anvil 12. A clamp 12A prevents movement of the strip of material during the punching operation.
The punching tool 13, as is shown in FIG. 2, is pivotally mounted adjacent one end of a lever 16, which is pivotally mounted intermediate its ends on a pin 19 on the body of the bush-forming apparatus. The end of the lever 16 remote from that connected to the tool 13 carries a roller 17 which engages a sliding carriage 18, movement of which is confined to reciprocation in the direction of the arrows B in FIG. 2. When the carriage 18 moves to the left, a shoulder 18A on the carriage 18 engages the roller 17 and causes the lever 16 to pivot about the pin 19 thereby moving the tool 13 so as to punch an aperture in the strip of material.
After the aperture-punching process is completed, the sliding carriage 18 is moved to the right in FIG. 2 and the punching tool 13 is retracted to the inoperative position shown in FIG. 2, by a return spring 20A.
On completion of the aperture-punching process a pair of gripping tongs 20 clasps the strip of material and moves it a predetermined distance towards a shearing mechanism 21. Thereafter the tongs 20 are returned to their initial position. The predetermined distance moved by the tongs 20 is equal to the length of the strip of material required to form one chain bush and to the spacing between the apertures punched in the strip.
Furthermore, the distance between the shearing edge of the mechanism 21 and the central axis of the punching tool 13 is a multiple of the length of material required to form one chain bush. In this way shearing of the strip takes place diametrically through the punched apertures and each length of strip from which a bush is to be formed has semicircular notches in its ends.
On completion of the shearing process the piece of material is formed into a cylindrical bush by a winding device 25, which includes first and second jaws 26, 26A each of which has a cylindrical concave surface, and a cylindrical forming bar 27 round which the cylindrical bush is formed. The dimensions of the device 25 are such that the inner and outer surfaces of the bush are accurately calibrated, and the two portions of the punched apertures at the ends of the flat piece of material are abutted so as to form an aperture of approximately circular cross section diametrically positioned on the seam of the bush.
In operation of the apparatus, movement of the sliding carriage 18, the tongs 20, the punching tool 13 and the shearing mechanism 21 are synchronized so that punching and shearing occur simultaneously and after forward movement of the tongs 20 has ceased.
Bushes produced by the aforementioned apparatus may be fitted in pairs to the backing plates of chain links with the seams of each pair, in exact face-to-face alignment, by the apparatus shown in FIGS. 3, 4 and 5.
The apparatus includes a revolving table 30 around the periphery of which there is a series of upstanding spring-loaded pins 31 each of which has a spring-loaded catch or nose 31A projecting radially from the pin 31 at an initially predetermined spacing from the surface of the table 30. The pins 31 are equally spaced-apart so that a backing plate 32 may be fitted over a pair of the pins 31 so as to bear on the surface of the table 30, with the pins 32 projecting through the apertures of the plate 32.
The pairs of pins 31 are arranged so that the respective catches 31A are in precise face-to-face alignment and when the catches 31A engage the apertures of the bushes the seams of the bushes are in precise face-to-face alignment.
In this way it is possible to ensure that the bush seams are in precise alignment and are situated in the zone of lowest stress in the completed chain.
Bushes 33 having circular apertures 34 through their seams are thereafter positioned over the pins 31 and each bush 33 is rotated about its respective pin 31 so that the spring-loaded catch 31A engages the apertures 34 thus to locate the bushes 33 relative to one another. This process is achieved by a spring-loaded frictional brake 35 shown in FIGS. 3 and 4. The brake 35 has a lever 37 of which the surface 36 has a friction lining, and the lever 37 is urged by a spring 37A away from a stationary housing 38 and into contact with the bushes 33 which are moved relative to the lever 37 by rotation of the table 30.
Final location of the bushes 33 relative to the respective backing plate 32 is achieved by a press-fitting operation during which the catch 31A remains engaged in the aperture 34 and the entire pin 31 moves relative to the table 30 due to the lower edge of the bush 33 bearing on a shoulder 31B of the pin 31.
A modified arrangement of locating pin 31 is shown in FIG. 6 in which the pin is hollow and the catch is in the form of a V-shaped spring 31B the apex of which projects radially through an aperture 31C in the wall of the pin.
Part of a complete roller chain including a link having bushes manufactured as above is illustrated in FIG. 7. The bushes 33, the apertures 34 and the backing plates 32 are each shown, and it will be evident that the apertures 34 are set in line. Sleeves 40 are fitted externally to the bushes 33 for engagement with the sprockets of a sprocket wheel, the links are interconnected by pins 41 which pass through and are a bearing fit in the bushes 33. The pins 41 are rivetted or otherwise connected to plates 42.
In a modified roller chain the pins 41 are replaced by cylindrical tubes secured to the plates 42.
In a modification of the apparatus for aligning the seams of the bushes the table 30 is in the form of an endless conveyor so that the processes of mounting the backing plate, mounting the bushes thereon, rotating the bushes relative to the pin, and press fitting the bushes to the backing plate are carried out with a linear motion of the backing plate.
Hitherto in the manufacture of roller chain links comprising two identical bushes press fitted to a backing or mounting plate in spaced-apart relationship, the bushes have been manufactured from a continuous strip of metal without waste of the material. The metal strip has been guided into the bush-forming machine by a reel and gripping tongs, and straightened and cut into short lengths as required. These short lengths have thereafter been pressed into the basic bush shape around a former and then pulled through a die so as to calibrate both the inside and the outside measurements of the bush. In this manner cylindrical bushes have been formed having a narrow slit or seam where the two edges of the flat metal have been abutted.
Links for use in roller chains, when utilizing such a bush, are known to have a short working life which, to a large extent, is due to the fact that the seams are not located in a preferred position before the bushes are press fitted to the backing plate. Thus several successive links of the chain may include bushes which have seams located in a zone of high stress and uneven wear of the chain occurs, especially in highly stressed chains such as drum chains.
An object of the present invention is to provide a method of and apparatus for manufacturing roller chain bushes as a result of which the bushes have apertures through which the seams pass.
A further object of the present invention is to provide apparatus for assembling a roller chain link, which enables precise alignment of the seams of bushes which have apertures through which the seams pass.
According to the present invention, there is provided apparatus for manufacturing bushes for a roller chain link from a strip of material, said apparatus including a strip-shearing mechanism and a bush-forming device in which cut lengths of the strip are formed into cylindrical bushes, including a punching device for punching apertures in the strip at such intervals that the shearing of the strip is effected through the apertures.
Further, according to the present invention there is provided apparatus for assembling a roller chain link having a backing plate and first and second seamed cylindrical bushes with circular apertures diametrically disposed through the seams thereof, said apparatus including a base, a table rotatably mounted on the base, and pairs of first and second spaced-apart locating pins upstanding from said table and on which the bushes are sliding fits, and the pins of each pair have face-to-face aligned spring-loaded catches for engagement with the apertures in the bushes, and a brake is mounted on the base and is adapted, when in use, to bear against the outer surfaces of the bushes to rotate same relative to the backing plate until the catches engage with the apertures.
Still further, according to the present invention there is provided a method of manufacturing roller chain links each of which includes a backing plate and first and second cylindrical seamed bushes, said method including the steps of provided a circular aperture in each bush diametrically through the seam thereof, mounting the backing plate on a template, positioning the bushes in spaced-apart relationship on the template for press fitting to the backing plate, mechanically rotating each bush until the apertures therein are substantially in face-to-face alignment with each other, and thereafter press fitting each bush to the backing plate.
Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a schematic diagram of apparatus for manufacturing roller chain bushes according to the present invention;
FIG. 1a is a plan view of the workpiece strip shown in FIG. 1;
FIG. 2 is a view, to an enlarged scale, of the hole-punching apparatus shown in FIG. 1;
FIG. 3 is a disc for aligning the seams of the bushes;
FIG. 4 is a detail of FIG. 3 shown to an enlarged scale;
FIG. 5 is a sectional view taken on the line A-B in FIG. 3, shown to an enlarged scale, of the bush alignment pin arrangement;
FIG. 6 is a modified arrangement of bush alignment pins; and
FIG. 7 is a part of a roller chain including a bush manufactured according to the present invention.
As is shown in FIG. 1, in apparatus for manufacturing bushes for roller chains, the material from which the bushes are formed is wound in a coil 10 from which a strip of material is fed through a series of spaced-apart rollers 11 so as to straighten the strip of material which thereafter successively undergoes the processes of aperture punching, shearing, and bush forming or winding.
In the aperture-punching process, the strip of material is formed over an anvil 12 and a punching tool 13, which is reciprocally slideable in a guideway 14, is automatically moved so that the tool 13 punches an aperture in the strip of material and discharges the punched material through a passage 15 in the anvil 12. A clamp 12A prevents movement of the strip of material during the punching operation.
The punching tool 13, as is shown in FIG. 2, is pivotally mounted adjacent one end of a lever 16, which is pivotally mounted intermediate its ends on a pin 19 on the body of the bush-forming apparatus. The end of the lever 16 remote from that connected to the tool 13 carries a roller 17 which engages a sliding carriage 18, movement of which is confined to reciprocation in the direction of the arrows B in FIG. 2. When the carriage 18 moves to the left, a shoulder 18A on the carriage 18 engages the roller 17 and causes the lever 16 to pivot about the pin 19 thereby moving the tool 13 so as to punch an aperture in the strip of material.
After the aperture-punching process is completed, the sliding carriage 18 is moved to the right in FIG. 2 and the punching tool 13 is retracted to the inoperative position shown in FIG. 2, by a return spring 20A.
On completion of the aperture-punching process a pair of gripping tongs 20 clasps the strip of material and moves it a predetermined distance towards a shearing mechanism 21. Thereafter the tongs 20 are returned to their initial position. The predetermined distance moved by the tongs 20 is equal to the length of the strip of material required to form one chain bush and to the spacing between the apertures punched in the strip.
Furthermore, the distance between the shearing edge of the mechanism 21 and the central axis of the punching tool 13 is a multiple of the length of material required to form one chain bush. In this way shearing of the strip takes place diametrically through the punched apertures and each length of strip from which a bush is to be formed has semicircular notches in its ends.
On completion of the shearing process the piece of material is formed into a cylindrical bush by a winding device 25, which includes first and second jaws 26, 26A each of which has a cylindrical concave surface, and a cylindrical forming bar 27 round which the cylindrical bush is formed. The dimensions of the device 25 are such that the inner and outer surfaces of the bush are accurately calibrated, and the two portions of the punched apertures at the ends of the flat piece of material are abutted so as to form an aperture of approximately circular cross section diametrically positioned on the seam of the bush.
In operation of the apparatus, movement of the sliding carriage 18, the tongs 20, the punching tool 13 and the shearing mechanism 21 are synchronized so that punching and shearing occur simultaneously and after forward movement of the tongs 20 has ceased.
Bushes produced by the aforementioned apparatus may be fitted in pairs to the backing plates of chain links with the seams of each pair, in exact face-to-face alignment, by the apparatus shown in FIGS. 3, 4 and 5.
The apparatus includes a revolving table 30 around the periphery of which there is a series of upstanding spring-loaded pins 31 each of which has a spring-loaded catch or nose 31A projecting radially from the pin 31 at an initially predetermined spacing from the surface of the table 30. The pins 31 are equally spaced-apart so that a backing plate 32 may be fitted over a pair of the pins 31 so as to bear on the surface of the table 30, with the pins 32 projecting through the apertures of the plate 32.
The pairs of pins 31 are arranged so that the respective catches 31A are in precise face-to-face alignment and when the catches 31A engage the apertures of the bushes the seams of the bushes are in precise face-to-face alignment.
In this way it is possible to ensure that the bush seams are in precise alignment and are situated in the zone of lowest stress in the completed chain.
Bushes 33 having circular apertures 34 through their seams are thereafter positioned over the pins 31 and each bush 33 is rotated about its respective pin 31 so that the spring-loaded catch 31A engages the apertures 34 thus to locate the bushes 33 relative to one another. This process is achieved by a spring-loaded frictional brake 35 shown in FIGS. 3 and 4. The brake 35 has a lever 37 of which the surface 36 has a friction lining, and the lever 37 is urged by a spring 37A away from a stationary housing 38 and into contact with the bushes 33 which are moved relative to the lever 37 by rotation of the table 30.
Final location of the bushes 33 relative to the respective backing plate 32 is achieved by a press-fitting operation during which the catch 31A remains engaged in the aperture 34 and the entire pin 31 moves relative to the table 30 due to the lower edge of the bush 33 bearing on a shoulder 31B of the pin 31.
A modified arrangement of locating pin 31 is shown in FIG. 6 in which the pin is hollow and the catch is in the form of a V-shaped spring 31B the apex of which projects radially through an aperture 31C in the wall of the pin.
Part of a complete roller chain including a link having bushes manufactured as above is illustrated in FIG. 7. The bushes 33, the apertures 34 and the backing plates 32 are each shown, and it will be evident that the apertures 34 are set in line. Sleeves 40 are fitted externally to the bushes 33 for engagement with the sprockets of a sprocket wheel, the links are interconnected by pins 41 which pass through and are a bearing fit in the bushes 33. The pins 41 are rivetted or otherwise connected to plates 42.
In a modified roller chain the pins 41 are replaced by cylindrical tubes secured to the plates 42.
In a modification of the apparatus for aligning the seams of the bushes the table 30 is in the form of an endless conveyor so that the processes of mounting the backing plate, mounting the bushes thereon, rotating the bushes relative to the pin, and press fitting the bushes to the backing plate are carried out with a linear motion of the backing plate.