JPS6151168B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transmission, and an object of the present invention is to provide a transmission that has a particularly simple configuration, does not apply excessive force to each component, and is less likely to fail.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of an embodiment of the present invention will be explained below with reference to the drawings showing an embodiment of the present invention as a driving device for a sewing machine.

In the figure, reference numeral 1 denotes a sewing machine main shaft, which is rotatably supported by a frame via a bearing metal 2. 3 and 4 are a pair of clutch plates that are fixed to the main shaft 1 at a distance, and 5 is a sliding tube that is slidably fitted onto the main shaft 1 through a metal between the clutch plates 3 and 4. , at one end thereof a plurality of protrusions 7 inserted into holes 6 provided in the one clutch plate 4;
7... is provided. Therefore, the main shaft 1, clutch plates 3, 4, and sliding tube 5 rotate integrally.
Reference numerals 8 and 9 indicate pulleys rotatably supported by the sliding tube 5 through bearings, and have clutch surfaces 10 and 10 on the portions facing the clutch plates 3 and 4, respectively.
It is equipped with 11. One of the pulleys 8 is connected via a belt 12 to a low speed drive source, and the other pulley 9 is connected via a belt 13 to a high speed drive source. 14 is the one clutch plate 3 and the sliding tube 5;
This is a spring placed between the two and presses the sliding tube 5 in the direction of the arrow N.

Reference numeral 15 denotes a support member fixed to the ends of the protrusions 7, 7, . 17 is a steel ball fitted into the recess; 18 is an operating member supported on the frame so as to be rotatable around an axis parallel to the axis of the main shaft 1; the upper end thereof can be engaged with the steel ball 17; Continuous cam surfaces 18a, 18b, 18
c is provided. The operating member 18 is the connecting rod 1
9 to a foot pedal and via a link 20 to a known cam arrangement. Therefore, when the foot pedal is depressed, the operating member is first rotated in the direction of arrow M, and the cam surface 18b is moved to a position facing the steel ball 17, thereby causing the sliding tube 5 to move in the opposite direction of arrow N to the spring 14. Clutch plate 3 is pressed against the action of
and the clutch surface 10 of the pulley 8 engage, and a low speed circuit is transmitted to the main shaft 1. When the foot pedal is further depressed, the cam surface 18c is moved to a position facing the steel ball 17, and the sliding tube 5 is moved so that the clutch plate 4 and the clutch surface 11 of the pulley 9 are engaged by the action of the spring 14. is moved, and high-speed rotation is transmitted to the main shaft 1. Based on the rotation of the main shaft, the known cam device also begins to rotate, and even if the foot pedal is released, the operating member 18
is held in that position by a cam device, and when the sewing operation is finished, the cam device rotates the operating member 18 in the opposite direction to that described above, whereby the main shaft 1 changes from high speed rotation to low speed rotation. It is stopped at a fixed position by the fixed position stopping means.

Reference numeral 21 denotes a brake member whose one end is rotatably supported on the frame by a shaft 22, and a brake shoe 23 is attached which extends along one of the clutch plates 3 and is pressed against the outer peripheral surface of the clutch plate. . 24 is a pin protruding from the operating member 18;
25 is a hole provided in the brake member 21;
Cam surfaces 25a and 25b are formed, and the pin 24 is inserted into the holes. Reference numeral 26 denotes a spring provided between the brake member 21 and the frame, which normally acts to press the brake shoe 23 against the outer peripheral surface of the clutch plate 3. The pin 24 and the hole 25 are arranged so that when the operating member 18 begins to rotate in the direction of the arrow M, the pin 24 and the cam surface 25a engage with each other, causing the brake member 21 to rotate slightly. 23 is pulled away from the outer peripheral surface of the clutch plate 3, and when the operating member 18 is further rotated, the pin 24 engages with the cam surface 25b and the operating member 18
The brake member 21 is configured to generate lost motion between the brake member 21 and the brake member 21, and the brake member 21 is held at that position regardless of rotation of the operating member 18.

27 is a fixed position stopping cam fixed to the main shaft 1 and has a notch 28; 29 is a first cam of the operating member 18;
Upper protrusion 1 formed on the left arm part in the figure
A stopper member is fitted into a hole 30 drilled through the hole 8d, and has a protrusion 31 at its upper end that can engage with the notch 28 of the cam 27, and a shoulder that can engage the upper protrusion from above. 32. Reference numeral 33 denotes a continuous rod that is inserted through the stopper member 29 and the downward protrusion 18e of the left arm portion, and has a head 34 at its upper end that can engage with the stopper member 29 from above. A nut is fixed to the lower end thereof via two cushioning rubbers 36. 35 is the stopper member 2
9 and the downwardly protruding portion 18e of the left arm portion, the spring is disposed on the connecting rod 33, and normally presses the stopper member 29 upward. When the operating member is rotated in the direction of arrow M, the protrusion 31 of the stopper member 29 moves out of the rotation locus of the cam 27, allowing rotation of the main shaft. Further, when the main shaft is stopped, the operating member 18 is rotated in the direction opposite to the arrow M, and both pulleys 8 and 9 are moved toward the clutch plates 3 and 4.
In a neutral state in which the main shaft is not engaged with the main shaft and in a state where the main shaft is rotating at a low speed, the protrusion 31 engages with the cam 27, and the protrusion 31 engages with the notch 28 to be stopped at a predetermined position. In addition, 37 indicates the operation member 18 in the direction of the opposite arrow M.
It is a spring that urges in the direction.

This embodiment is configured as described above, and the operating member 1
Since the sliding tube 5 receives a pressing force in the axial direction on its center line based on the rotational operation of 8, an excessive force is not applied to each component, and a speed change operation can be performed extremely smoothly. Further, since the rotating part and the non-rotating part are connected through the steel balls 17, there is little wear between them and smooth rotational movement can be obtained. Also, operation member 1
At the beginning of the rotation of step 8, the brake member 21 is slightly rotated to separate the brake shoe 23 from the pulley circumferential surface, and the brake member does not rotate and remains at that position regardless of subsequent rotation of the operating member 18. Since it is held, the operating member can be rotated smoothly.

As described in detail above, the present invention fixes a pair of clutch plates spaced apart from each other on the main shaft, and connects one end of a sliding tube supporting a high-speed rotation pulley and a low-speed rotation pulley arranged between the clutch plates to the pulley. The clutch plate protrudes outward through one of the clutch plates facing the clutch plate, and is connected to the operating member via a steel ball supported on the protruding end side.It has an extremely simple configuration and can perform two-speed shifting. Therefore, it is possible to provide a device which is excellent in practice and can smoothly perform the speed switching operation.

[Brief explanation of the drawing]

Fig. 1 is a front view of a transmission embodying the present invention, Fig. 2 is a right side view, and Fig. 3 is the same as Fig. 2.
4 is a sectional view taken along the - line in FIG. 2. In the figure, 1 is a main shaft, 3 and 4 are clutch plates, 5 is a sliding tube, 8 and 9 are pulleys, 14 is a spring, 17 is a steel ball, 18 is an operating member, and 18a, 18b, and 18c are cam surfaces.

Claims (1)

[Scope of Claims] 1. A main shaft 1, a pair of clutch plates 3, 4 fixedly arranged on the main shaft at an interval, and a pair of clutch plates 3, 4, which are slidably attached to the main shaft between the clutch plates, and the A protrusion 7 protruding outward from a hole 6 provided in one clutch plate 4
a sliding tube 5 having a sliding tube 5, each rotatably disposed on the sliding tube and having a clutch surface at a portion facing each of the clutch plates,
Pulleys 8, 9 each rotated at different speeds
a support member 15 that is fixed to the protrusion of the sliding tube and supports the sphere 17 on the axis of the main shaft; and a support member 15 that is arranged between the sliding tube 5 and one clutch plate 3 and that is normally attached to the sliding tube. The spring 14 presses the protrusion in a direction that protrudes further outward from the clutch plate 4.
and is movable with respect to the frame and arranged to engage with the sphere 17, and moves the sliding tube 5 in cooperation with the spring 14 so that only one pulley 8 engages with the clutch plate 3 facing it. Matching cam surface 18b
, only the other pulley 9 has a cam surface 18c that engages with the clutch plate 4 facing it, and a cam surface 18a that neither pulley engages with the clutch plate; A transmission characterized by comprising an operating member 18 with which each cam surface engages in sequence.