Patent GB-1321049-A (GB)
Title: Punch press for punching a cylindrical flexible metal endless band
IPC: B21D28/36
Filed: 1970-08-12
Abstract: 1321049 Punching RICH TOOL & DIE CO 12 Aug 1970 38823/70 Heading B3W In a machine for punching holes at predetermined intervals in a cylindrical flexible metal band an annular rotatable workholder comprises a plurality of similar truncated sector shaped plates 99 having band supporting fingers 115 closely spaced around one periphery of the workholder and mounted for radial adjustment relative to the plates which are simultaneously moved radially outward or inward, by coned cam rings 97, 98 mounted in the centre of the workholder to allow the band to be located by the fingers and subsequently moved in the opposite radial direction to cause the fingers to grip the band and indexing means control the angular feed of the band. The plates 99 are mounted on a base table 92 which is freely rotatable about a bearing 91 and is indexed manually or by automatic means not described, a radially adjustably mounted pawl 81 being released from one hole in an indexing table 93 fixed to the underside of table 92 by slight depression of a lever 80 and urged upwardly into the next selected hole by spring 88. A pair of slides 107 on the underside of each plate 99 engages in pairs of guides 94 on the table 92 and the plates are urged inwardly by springs (106), Fig. 8 (not shown), acting between outer and inner retainers 95 and 105 on the table 92 and the plates 99 respectively. The inner cam ring 97 urged upwardly by springs 103 is retained by a camming bolt 101. Upstanding portions 116 of the fingers 115 have recesses 117 for locating the band, and a longitudinal bore 118 for dowels such as 120, Fig. 17, and holes 127<SP>1</SP> for mounting adapters 127 for guiding the band. The fingers can be mounted with the portions 116 innermost (Fig. 14) to accommodate bands of small diameter. The base-and-index-table unit is mounted on a carriage 70 manually reciprocable relative to a base 50 by means of a rack and pinion device 67, 75, Fig. 1. A punch supporting frame 130 is vertically adjustable on the base by a pneumatically actuated ram 132. Pivoted to the frame 130 is a frame 150, Fig. 1 carrying a die bed 151, Fig. 36, and a hydraulic punching ram157. Adjustably mounted on the die bed is a bandlocating roller 166. Interchangeable punch and die pairs are connectable to the ram and the die bed by keys 158 and 165 respectively. In use, an index plate having the same, a multiple or a fraction of the number of holes to be punched in a band is mounted on the plate 92. The bolt 101 is loosened to withdraw the inner cam ring 97 and a gauge 122, Fig. 14, is placed over the outer cam ring with the lower inner edge of a gauge ring 123 abutting the outer edge of the outer cam ring 98. A rod 125 is radially adjusted to contact the inner face of a finger portion 116, the holding surface of the fingers being on a radius slightly less than the radius of the band to be punched. The fingers are clamped in adjusted position and the band roller mounting is adjusted. If the band is to be mounted in the outer recesses 117 it is placed over the fingers and the bolt 101 tightened to depress the cam ring 97 and force the plates 99 outwardly. If the band is mounted in the inner recesses the cam ring is first depressed, the band located and the ring withdrawn, the plates being urged inwards to cause the fingers to grip the band tightly by the springs (106), Fig. 8 (not shown). The height and tilt of the punch frame 150 is adjusted, the angularity of the frame being indicated by a gauge 155, Fig. 1. The band is rotated manually and indexed as described. For punching holes of smaller diameter than the thickness of the band a shroud 161 biased by springs 160 is provided for the punch.