GB945873A - Improvements in or relating to punching devices - Google Patents

Abstract

945,873. Sub-press mechanisms. HOUDAILLE INDUSTRIES Inc. Nov. 20, 1962. No. 43886/62. Heading B3W. A sub-press mechanism 10 comprises a C-shaped frame 11 having upper and lower arms 12, 13 with axially aligned bores 16 and 19 respectively, a die 15 removably secured in the bore 19; a punch and guide assembly 14 reciprocably disposed in the upper arm, said assembly including an elongated punch guide sleeve 27, an upper collar 28 slidably surrounding the sleeve and a lower collar 29 surrounding the lower end of the sleeve, a stripping spring 30 around the sleeve and biasing the collars apart, a pair of snap rings 38, 39 retaining the collars against the stripping spring, the collars each having a surface 31, 32 in slidable contact with the upper arm 12, a punch 22 slidably received within the sleeve 27 and having a head 43 projecting above the upper collar, a manually removable snap ring 44 securing the head to the upper collar, the lower collar 29 having a downwardly directed recess 35 defining a shoulder within the axial limits of the working end 21 of the punch, the recess being adapted to receive a stripper button 36, and there being a lifting spring 45 acting between the upper arm 12 and the upper collar 28 to bias the punch and guide assembly away from the die. The punch is prevented from turning in the sleeve by a key 51, the sleeve is secured to the lower collar by a pin 42 and the lower collar is keyed for sliding movement only by a pin 18. The die is retained in the lower arm by a set-screw and is locked against angular movement by a pin 25. The pin 18 has a bifurcated end, Fig. 4, at least one of the bifurcations being resilient and the dimension across the bifurcations being about 0.005 inches larger than the diameter of the hole 17.