Patent GB-711856-A (GB)
Title: Apparatus for severing the separate tetrahedra from a coherent string of tetrahedra
IPC: B65B61/06
Filed: 1951-05-24
Abstract: 711,856. Making pa,per &c. bags. HERMORIAN, Ltd. May 24, 1951 [May 21, 1951], No. 12191/51. Class 94 (2) [Also in Groups VIII and XXX] Mechanism for severing the separate tetrahedra t from a string of these elements formed by pressing and sealing together the opposite sides of a tubular element at equallyspaced intervals in alternately - perpendicular directions comprises an endless conveyer 18, Fig, 2 which is provided with transverse stays 24 spaced apart a distance equal to the length of two tetrahedra and at its delivery end passes over a guide wheel 28 having its teeth spaced apart a distance equal to the spacing of the stays 24, and two sets of cutters each arranged to act upon alternate joints in the string. The tetrahedra may be made from a tube which is shaped as described in Specification 691,649, [Group XXVIII] and formed into packages as described in Specification 711,855, and are led as a continuous string to the upwardly-moving conveyer 18 which is in the form of two parallel chains connected by the stays 24; the ends of the stays are shaped to provide guides for the tetrahedra. At the delivery end the chains pass over two sprocket wheels 28 carried on a lever 36 which can be swung vertically about on axle 38 by a cam 44 coacting with a roller 40 on the lever. In order to avoid the alternate tensioning and slackening of the conveyer 18 caused by the vertical movements of the sprocket wheels, the conveyer is tensioned by passing over a sprocket wheel 46 on a pivoted lever 48 controlled by a cam 54. Beneath the sprocket wheel 28 are two superposed sets of cutters 64, 64', Fig. 7, each set consisting of two knives pivoted about a vertical axis and geared together for simultaneous operation; the upper set acts on those joints in the string which extend longitudinally of the machine and the lower set cuts the alternate and transverselyextending joints. Each set is controlled by lever mechanism from a cam 68. Sleeves 84, 86 are positioned above both sets of cutters for guiding the tetrahedra to cutting position. In operation, the leading tetrahedra are deflected downwardly by the sprocket wheels 28, and the cam 44 arranged so that it first lowers the sprocket wheels to position the lower-most joint in the swing opposite the lower cutters 64 and then raises them at a speed equal to the downward feed by the conveyer whereby the joint is maintained stationary for the cutting operation which is then effected by the timed operation of the cam 68; the cut tetrahedron t' is then deposited upon a conveyer 94 en the form of two parallel endless bands. Continued rotation of the cam 44 then lowers the sprocket wheels and therefore feeds the tetrahedra downward at rapid speed to position the next joint opposite the cutters 64' which are operated by the cam 68 while the sprocket wheels are again being lifted. In order that all the tetrahedra may be similarly positioned on the conveyer 94, a cam 112, Fig. 7, is operated to move a hooked member 104 into position to support each tetrahedron t" which is being cut by the upper cutters 64<SP>1</SP> and then lower and swing the tetrahedron in inverted position on to the conveyer. One or more of the upwardly-flared surfaces of the upper guide sleeve 84 may be resilient or hinged so that, should the feed of tetrahedra be blocked in the cutters, it is pushed outwardly to open a switch in the main motor circuit.