GB634797A - Improvements in and relating to knitting machines - Google Patents

Abstract

634,797. Knitting-machines. COTTON, Ltd., W., LYNAM, J. E., and McCARTHY, P. G. April 28, 1947, No. 11246. [Class 74 (ii)] A stop motion is provided in a straight-bar machine to render the machine inoperative if instruments, which co-operate with the needles during a phase of the knitting operations when the normal action of the needles is varied, fail to return to an initial position upon resumption of normal knitting, or if the needles fail to vary their movements for co-operation with the instruments. The invention is described in connection with a machine described in Specification 602,324, wherein auxiliary pressers are operated to engage the needles during the transfer of the initial course from the welt hooks to the needles on completion of the welt and thereby facilitate the withdrawal of the welt hooks. During the transference, the needle movement is interrupted by a press rod 12 that shogs the needle bar pressing truck to modify the pressing movement of the needles, which movement opens a switch 30 in a relay in an electric circuit. A knock over rod 13 is shogged to modify the movement of the knockover bits and to open a switch 31 which is in parallel with the switch 30 of the relay. A mis-pressing rod 20 is then shogged to bring the auxiliary pressers into operation and to close a switch 29 which is in series with the other two switches of the relay. If the pressing movement of the needles has not been modified, the switch 30 will remain closed and, upon operation of the switch 29, the relay will be energized to operate switch 26 and to stop the machine. When the machine resumes normal knitting, the mis-pressing rod 20 returns under the action of a spring 121 and opens switch 29, the knock over rod 13 returns under the action of a spring 66 and closes switch 31 and the press rod 12 returns under the action of a spring 55 and closes the switch 30. Should, however, the rod 20 fail to return, the switch 29 will remain closed and the closing of switches 30 or 31 will stop the machine. In an alternative arrangement, the switches 30 and 31 may be in series and both in parallel with the switch 29 so that failure of one switch to close, de-energizes the relay and stops the machine.