APPARATUS FOR POSITIONING, HOLDING AND DIE-CUTTING RESILIENT AND SEMI-RESILIENT STRIP MATERIAL

• US 3,861,261 A
• Filed: 11/09/1973
• Issued: 01/21/1975
• Est. Priority Date: 11/09/1973
• Status: Expired due to Term

• Current Assignee: Rbx-Rubatex Incorporated AEA Investors Incorporated
• Original Assignee: Maxey W. Clarence
• Inventors: Maxey, W. Clarence
• Primary Examiner(s): Meister, J. M.
• Application Number:
  US05/414,338
• Time in Patent Office: 438 Days
• Field of Search: 83/387,386,385,389,420,373,206,416,212,419
• US Class Current: 83/387
• CPC Class Codes: B26D 3/10 Making cuts of other than simple rectilinear form cutting-out B26F
• CPC Class Codes: B26D 7/015 for sheet material or piles of sheets B26D7/018 and B26D7/02 take precedence
• CPC Class Codes: B26F 1/40 using a press, e.g. of the ram type presses in general B30B
• CPC Class Codes: Y10T 83/5778 With resilient drive element
• CPC Class Codes: Y10T 83/6569 With means to stop work conveyor
• CPC Class Codes: Y10T 83/6574 By work-stopping abutment
• CPC Class Codes: Y10T 83/6576 By opposed lateral guide means

Abstract

A novel positioning and die-cutting mechanism together with an automatic material feed mechanism used in association with cutting presses, to facilitate both manual and automatic feeding of, and the accurate positioning and cutting of soft cellular rubber and/or plastic material, in continuous strip form, which mechanisms provide significantly improved safety factors and production output of articles made therefrom. Apart from the power-operated rollers of the feed mechanism, the improved diecutting mechanism includes a sensitive cam-operated lever and linkage system in conjunction with spring-biased positioning and retaining member sub-assembly embodying soft-rubber-faced positioning bars which in correlation with the downward and upward movements of the press cycle, said bars precisely close to position, hold and then automatically release the strip material after the material is die-cut. After the die-cut material is removed from the die, part of the circuitry is again automatically activated to cyclically feed the resilient cellular stock material in timed relationship beneath the elevated press head, whereupon the process is repeated.

Claims

1. A positioning and holding mechanism for accurately positioning and holding lengths of rubber, plastic and other resilient material of strip form during die-cutting in conjunction with a press having a reciprocable die-carrying press head movable toward and away from a press- or die-bed upon which said strip material is supported during the cutting thereof, said mechanism comprising in combination:

a. a pair of rotary cam-operated, laterally reciprocable positioning-and-holding bar assemblies mountable on said press bed at opposite sides of a central feed path for said strip material each of said bar assemblies including;

1. an elongated rigid bar structure having a gripping edge disposable parallel to the strip material to be fed in a foreand-aft direction through the press. 2. rod means on said bar structure and extending transversely away from the gripping edge, and having cam follower means at an end oppositely remote from said gripping edge. 3. press-supportable bracket means for slidably supporting said rigid bar structure via its rod means to facilitate lateral reciprocation of said bar structure between gripping and nongripping positions; and

4. resilient means operatively interposed between said bracket means and rigid bar structure to normally bias said bar structure to a neutral non-gripping position away from the strip of material to be gripped and die-cut, and to constantly urge said cam follower means of said bar structure'"'"''"'"'s rod means into engagement with said rotary cams; and

b. a pair of motivation linkage assemblies mountable at lateral opposite sides of a cutting die and so as to depend from beneath said press head, and operatively connected via said rotary cams with said positioning-and-holding bar assemblies, said linkage assemblies being operative responsive to down and up cycling of said press head to effect said reciprocable movement of said bar assemblies to properly position and hold said strip from opposite longitudinal sides thereof during cutting.

2. a corresponding pair of motivating linkage assemblies respectively operatively connected with said respective rotary cam-operated positioning-and-holding bar assemblies, said linkage assemblies each including component means dependingly attached to said press head and operative responsive to downward and upward cycling of said press head during die-cutting;

c. cutting die means including a cutting die of predetermined configuration affixed to a lower portion of said press head, for engagement with a die-bed oppositely therefrom on said press. d. material stop and length-guaging means at a rearward press portion behind said die-bed, and including adjustment means to facilitate adjustable disposition of the stop means to enable cutting said strip material into different predeterminable lengths; and

e. electrical circuitry embodying switch means for selectively activating the downward and upward cycling of said power-operated press head by a single operator.

3. press-supportable bracket means for slidably supporting said rigid bar structure via its rod means to facilitate lateral reciprocation of said bar structure between gripping and non-gripping positions;

and

4. A positioning and holding mechanism as defined in claim 3, wherein said angular links of said linkage assemblies, as disposed at said lateral opposite sides of said cutting die, are disposed relative to one another so as to have their respective ends which slidably traverse said respective pivot blocks converge only slightly toward said strip material and one another when in a normal non-operative or non-gripping position;

and said crank arms of said rotary cam shafts when in said same position extend angularly upright therefrom and also converge toward said strip material and one another;

said angular dispositions and biasing of said linkage assembly components contributing to lock-free operation of the mechanism.

5. A positioning and holding mechanism as defined in claim 4, wherein said crank arms and angular links are so proportioned and interrelated that when said rotary cams are operatively rotated and said press head is in a fully lowered cutting position attendant the downward press cycle, said crank arms are downwardly disposed at the same relative angle from a vertical reference line as when upwardly and oppositely disposed in said normal non-operative or non-gripping position.

6. A positioning and holding mechanism as defined in claim 1, wherein each of said elongated rigid bar structures of paragraph a1 has resilient cushioning means along said gripping edge, which cushioning means is deformable to accomodate frictional gripping of material strips of slightly varying width.

7. A positioning and holding mechanism as defined in claim 1, wherein each of said elongated rigid bar structures of paragraph a1 has resilient cushioning means along said gripping edge;

and said rigid bar structure and rod means having adjustable connecting means to vary the distance from said gripping edge to said cam follower means, by which said adjustable connecting means and said cushioning means collectively provide means for said mechanism to frictionally grip material strips of widely varying width.

8. A system for sequentially feeding positioning, holding and die cutting into predeterminable lengths a supply strip of rubber, plastic and other resilient and semi-resilient material in conjunction with a power-operated press having a reciprocable cutting die-carrying press head movable toward and away from a press- or die-bed upon which said strip material is supported during the operation thereof, said system comprising in combination a. means for guiding a continuous strip supply of said material into and through said press between the press head and press or die-bed;

b. a positioning and holding mechanism for accurately positioning and holding the strip material during die-cutting thereof;

said mechanism comprising

9. A system as defined in claim 8, further including means for effecting both manual and automatic electrically powered feeding of said strip material into said press.

10. A system as defined in claim 9, wherein the electrical circuitry includes a subcircuit and swItch means interrelated with said automatic feeding;

and said material stop and length-gauging means of paragraph d include resilient means for mounting a stop member thereof so as to be moved by the feeding strip material and thereby yieldable retract against and temporarily trip a relay switch of said subcircuitry to interrupt said automatic feeding of said strip material preparatory to the downward cycling of and die-cutting by said cutting die means;

said circuitry being such as to automatically restart said automatic feeding of said strip material responsive to subsequent manual removal of the cie-cut strip of material from the die-bed.

11. A system as defined in claim 10, wherein said cutting die includes a cutting edge of predetermined shape, and said material stop member includes a seat member contoured to correspond with said predetermined shape of said die-cutting edge, to thereby complementally receive a cut edge of an advancing strip of material therein and to establish predetermined uniform lengths of said strip material being cut.

12. A system as defined in claim 11, wherein said cutting die includes double cutting edges of predetermined different outline shape to correspond with and to simultaneously cut two separate end configurations for the strip material, said double cutting edges constituting means to provide respectively opposite hand terminal cuts to the strip material, one of which completes a final cut for an outgoing completed predetermined length of said strip material, and the other of which constitutes a first cut of the next-in-line segment of strip material.

13. A system as defined in claim 9, wherein said means of paragraph a for guiding said strip material into said press include a pair of horizontal rollers spaced vertically apart to frictionally grip the thickness of the material, and a pair of vertical rollers spaced laterally apart corresponding to the width of said material, said vertical rollers disposed adjacent said horizontal rollers, and both pair of rollers disposed at an entry side of said press.

14. A system as defined in claim 13, wherein said horizontal pair of rollers also constitute part of said means for automatically feeding said strip material into the press, and at least one of said horizontal rollers being driven by an electrical power source connected into said circuitry, which circuitry includes a start-and-stop switch selectively manually operable to facilitate initiating infeed of said strip material.

15. A system as defined in claim 14, wherein said means for effecting said automatic power feeding of said strip material include an electrically activated clutch means and an electrically activated brake means operatively connected with one of said horizontal rollers.

16. A system as defined in claim 15, wherein said circuitry includes interrelated subcircuits for effecting substantially simultaneous activation of said clutch means with a de-activation of said brake means, and vice versa.

17. A system as defined in claim 13, further including means for selectively adjusting the spacing between said pairs of rollers to accomodate strip material of varying thickness and width.

18. A system as defined in claim 8, wherein said means of paragraph a for guiding said strip material through said press further includes anti-friction guide means including at least one pair of generally cylindrical members disposed at the rearward portion of said press bed with their axis vertically, and disposed at laterally opposite sides of said feed path.

19. A system as defined in claim 18, including a plurality of said anti-friction guide means, and having means to mount them in rows of selectively variable distances apart to accomodate strip material of different predetermined widths.

20. A system as defined in claim 8, wherein each of said positioning-and-holding bar assemblies of paragraph b1 include

21. A system as defined in claim 20, wherein each of said elongated rigid bar structures include selectively applicable resilient cushioning means to define a material gripping edge;

and said rigid bar structure and rod means having adjustable connecting means to vary the distance from said gripping edge to said cam follower means, by which said adjustable connecting means and said cushioning means collectively provide means for said mechanism to frictionally grip material strips of widely varying width.

22. A system as defined in claim 8, wherein said positioning-and-holding bar assemblies of paragraph b1 each include an elongated rigid bar structure having a resilient gripping edge parallel to the edges of the strip material to be gripped therebetween;

wherein said rotary cams have camming surfaces of generally parabolic character and are fixedly mounted eccentrically on rotatable cam shifts disposed parallel to said material-feed path and to the longitudinal gripping edge of said bar structure of paragraph a1, said rotatable cam shafts having actuating crank arms attached thereto; and

said component means of said linkage assemblies respectively including angular links having one end respectively pivotally mountable to and beneath said press head and with respective opposite ends associated with means pivotally connectable with said respective actuating crank arms of said rotary cams shaft so as to provide requisite cyclic positioning, holding and subsequent release of said strip material responsive to said down and up cycling of said press head.

23. A system as defined in claim 22 wherein said angular links of said linkage assemblies include respective longitudinally adjustable drive shaft members each having a free end slidable connected to and through an aperture in a component pivot block associated therewith, the latter of which at a point offset from said aperture provides said means for effecting pivotal connection with said crank arms of said rotary crank shaft;

said linkage assemblies further including compression springs encircling each of said drive shaft members to continually bias said pivot block against an adjustable stop on a free end of said drive shaft.

24. A system as defined in claim 23, wherein said angular links of said linkage assemblies are disposed at said lateral opposite sides of said cutting die, are disposed to provide some lost motion as they slidably traverse said respective pivot blocks, and are disposed relative to one another so as to have their respective ends converge only slightly toward said strip material and one another when in a normal non-operative or non-gripping position;

and said crank arms of said rotary cam shafts when in said position extend angularly upright therefrom and also converge toward said strip material and one another;

said angular dispositions and biasing of said linkage assembly components contributing to an effective and lock-free operation of the mechanism.

25. A system as defined in claim 24, wherein said crank arms and angular links are so proportioned and interrelated that when said rotary cams are operatively rotated and said press head is in a fully lowered cutting posiTion attendant the downward press cycle, said crank arms are downwardly disposed at the same relative angle from a vertical reference line as when upwardly and oppositely disposed in said normal non-operative or non-gripping position.