Cam control mechanism of carriage in a flat knitting machine

Abstract: A cam control mechanism of a carriage in a flat knitting machine capable of controlling vats with different heights from the carriage depending on the requirement, without having to mount plural solenoids on the carriage for controlling vats with different heights on the jacks for composing the knitting needles in a flat knitting machine. The cam control mechanism includes a bottom plate (1) of a carriage, an opening (2) in said bottom plate of said carriage, and a cam (3) composed of an actuating part (4) and a shaft part (5) disposed with the actuating part (4) of the cam (3) projecting out from this opening (2) below said bottom plate (1). A support bracket (11) is disposed for supporting the shaft part (5) freely movable in a vertical direction in the carriage. One end of a spring (17) freely fitted to the shaft part (5) abuts against the support bracket (11). The other end of the spring (11) abuts against a flange (18) disposed on the shaft part (5). The cam (3) is thrust upward by an elastic force of the spring (11). A step motor (19) is mounted on the front end of the shaft part by means of the support bracket so that the front end (21) of the main shaft (20) of the step motor (19) may abut against the front end (22) of the shaft part (5). The cam (3) is controlled in the vertical direction by a vertical motion of the main shaft due to actuation of the step motor (19).

Description: The present invention relates to a cam control mechanism of carriage in a flat knitting machine. When knitting a fabric by a flat knitting machine, a cam is caused to act (inact) on the butt of one jack composing knitting needles from a carriage running right and left above the needle bed, and the motion of the needles is manipulated by controlling the convex butts of different heights formed on each jack. That is, hitherto, jacks with large (tall) butts and jacks with small (short) butts were combined, or jacks with large butts, jacks with medium (of medium height of large and small butts) butts, and jacks with small butts were combined, and the cam was caused to act on butts of jacks different combinations by disposing two or three solenoids on the carriage to actuate the solenoids, thereby causing the cam to act on large and small butts, or large, medium and small butts. Accordingly, in order to control the jacks forming large and small, or large, medium and small convex butts as required, two or three solenoids were needed, and mounting of these solenoids on the carriage complicanted the internal structure of the carriage, and the weight of the carriage which runs becomes heavy, and in the carriage repeating running, inverting and stopping, adverse effects due to inertia when stopping could not be disregarded. GB-A-2198753 discloses a device for controlling a movable cam in a flat knitting machine by means of a step motor controlled by an electronic programming device of the machine. The step motor is fixedly arranged on a movable cam holder and is kinematically coupled with a stationary part of the machine. The coupling may be by means of a screw thread on the motor shaft. The device may be used to move a cam in the direction of needle movement or at right angles to the direction of needle movement. OBJECT AND SUMMARY OF THE INVENTION The invention is developed in the light of such problems, and it is a primary object thereof to present a cam control mechanism of a carriage in a flat knitting machine capable of controlling butts of various heights with cam from the carriage, without mounting plural solenoids on the carriage. According to the present invention, there is provided a cam control mechanism of a carriage in a flat knitting machine, which includes a bottom plate of a carriage, an opening in said bottom plate of said carriage, a cam having an actuating part and a shaft part disposed with the actuating part of the cam projecting out from the opening below said bottom plate, a support bracket disposed for supporting the shaft part to be freely movable in a vertical direction in the opening in the bottom plate, one end of a spring freely fitted to the shaft part abutting against the support bracket, the other end of said spring abutting against a flange disposed on the shaft part, the cam being thrust upward by an elastic force of the spring, and a step motor mounted on the front end of the shaft part by means of the support bracket so that the front end of the main shaft of the step motor may abut against the front end of the shaft part, the main shaft of the step motor being coupled by a thread to the rest of the step motor so that actuation of the step motor causes rotational and vertical movement of the main shaft whereby, the cam is controlled in the vertical direction by a vertical motion of the main shaft due to actuation of the step motor. BRIEF DESCRIPTION OF THE DRAWING The drawing is an explanatory diagram of a section of an embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, an embodiment of the invention is described below. Numeral 1 is a bottom plate of a carriage in a flat knitting machine, and an opening 2 is made in this bottom plate 1 of the carriage. This opening 2 is intended for moving an actuating part 4 of a cam 3 in and out. The cam 3 abuts against a butt of a jack (not shown), for example, disposed parallel on the needle bed to control this jack. The cam 3 is formed in one body by the actuating part 4 and shaft part 5. The actuating part 4 of the cam 3 is composed of a flange 6 positioned inside of the carriage of the bottom plate 1, and a protrusion 7 projecting from the opening 2. While the flange 6 is abutting against the inside surface 8 of the bottom plate 1, the protrusion 7 of the actuating part 4 is projecting more than half from the outside surface 10 of the bottom plate 1. The cam 3 is disposed in a state in which the shaft part 5 is erect on the flange 6 of the actuating part 4. In order to support this shaft part 5 freely movable in the vertical direction, a support bracket 11 is set up on the bottom plate inside surface 8 in the carriage. The support bracket 11 is disposed in the bottom plate 1 in an inverted L-section, and a penetration hole 13 is drilled in a convex part 12 so as to insert the shaft part 5 of the cam 3. The shaft part 5 of the cam 3 is inserted in this penetration hole 13, and its upper end part 14 projects upward from the top 15 of the convex part 12 of the support bracket 11. A spring 17 is fitted freely onto the projection 16 of the shaft part 5, and is arranged so that one end may abut against the top 15 of the convex part 12. Furthermore, near the upper end of the projection 16 of the shaft part 5, a flange 18 made of C- or E-clips is provided, and the other end of the spring 17 is abutting against this flange 18. By the elastic thrusting of the spring 17, the cam 3 is always thrust upward. A bracket 11a for supporting the step motor 19 mentioned below is disposed on the support bracket 11. The step motor 19 is mounted on the upper part of the bracket 11a, so that a main shaft 20 of the step motor 19 may extend downwardly. A front end 21 of the main shaft 20 is designed to abut against the front end 22 of the shaft part 5 of the cam 3. The main shaft 20 of the step motor 19 is designed to move up and down as it rotates when operating. Numeral 23 is a sensor, which detects the preset zero point position of the cam 3. By thus composed cam control mechanism of carriage in a flat knitting machine, by actuating the main shaft 20 by sending a pulse signal to the step motor 19, the main shaft 20 rotates, and ascends or descends. As the main shaft 20 is lowered, the cam 3 which has been thrust upward by the elastic force of the spring 17 is pushed downward by resisting the elastic thrusting force of the spring 17, and the protuberance 7 of the cam 3 is projected by a specified length from the opening 2 of the bottom plate 1. When the protuberance 7 of the cam 3 is projected the most from the bottom plate 1, it acts on the butt which is a large or small convex part of the jack, thereby controlling the needle. Besides, sending a pulse signal to the step motor 19, the main shaft 20 is actuated to raise the main shaft 20 slightly, so that the cam 3 is thrust upward by the elastic force of the spring, and the entire cam 3 goes up slightly. In consequence, the protuberance 7 is slightly set back into the carriage. In this state, the cam 3 does not act on the butt having a small convex part of the jack, but acts on the butt having the large convex part, thereby controlling this jack. Furthermore, a pulse signal is sent to the step motor 19 to actuate the main shaft 20, and the main shaft 20 is raised, and when the cam 3 is raised most to the carriage side, the projection of the protuberance 7 of the cam 3 from the opening 2 is small, and in this state the protuberance 7 of the cam 3 does not act on the jack of the butt having large and small convex parts. By operating the step motor 19 in this manner to move the main shaft 20 up and down, the cam 3 is moved up and down, and by controlling the projecting length of the cam from the carriage bottom plate 1, the jack of the butt having large and small convex parts can be controlled. In the foregoing explanation, the jack of the butt having large and small convex parts is controlled, but the cam control mechanism of the invention may be applied to easily control not only the jack with large and small butts as mentioned herein, but also the jack with large, medium and small convex butts, or jacks with butts of various different height aside from large, medium and small sizes. Control of the different sized jacks depends upon the length of the protuberance 7 below the bottom surface of the bottom plate 1.

Claims: A cam control mechanism of a carriage in a flat knitting machine, which includes a bottom plate (1) of a carriage, an opening (2) in said bottom plate (1) of said carriage, a cam (3) having an actuating part (4) and a shaft part (5) disposed with the actuating part (4) of the cam (3) projecting out from the opening (2) below said bottom plate (1), a support bracket (11) disposed for supporting the shaft part (5) to be freely movable in a vertical direction in the opening (2) in the bottom plate (1), one end of a spring (17) freely fitted to the shaft part (5) abutting against the support bracket (11), the other end of said spring (17) abutting against a flange (18) disposed on the shaft part (5), the cam (3) being thrust upward by an elastic force of the spring (17), and a step motor (19) mounted on the front end of the shaft part (5) by means of the support bracket (11) so that the front end (21) of the main shaft (20) of the step motor (19) may abut against the front end (22) of the shaft part (5), the main shaft (20) of the step motor (19) being coupled by a thread to the rest of the step motor (19) so that actuation of the step motor (19) causes rotational and vertical movement of the main shaft (20) whereby, the cam (3) is controlled in the vertical direction by a vertical motion of the main shaft (20) due to actuation of the step motor (19). A cam control mechanism according to claim 1 characterised by a sensor (23) disposed adjacent to said said cam (3) for determining a zero position of said cam (3).

Inventors: NAKAMORI TOSHINORI, NAKAMORI, TOSHINORI
Applicants: SHIMA SEIKI MFG, SHIMA SEIKI MFG., LTD.
Application year: 1990
Main classification: D04B15
IPC codes: D04B15