JPH0728963B2 - Timing adjustment device between needle bar, balance and feed dog of sewing machine - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a timing device for a needle bar and a balance motion with respect to a sewing motion of a sewing machine.

2. Description of the Prior Art Sewing machines are designed to be able to make timing adjustments in the factory and in fields that have the purpose of properly correlating the movements of various stitch forming devices.

(Problems to be Solved by the Invention) However, it is known that adjustment of timing in a factory consumes a lot of time and is uneconomical. Further, the timing device incorporated in the sewing machine increases the manufacturing cost, and it is difficult to expect that the timing of the sewing machine is properly maintained when the adjusted period is long.

It is a primary object of the present invention to allow the needle bar and balance to be automatically timed with the feed dog during assembly of the sewing machine without making adjustments such as changing model.

Another object of the present invention is to simplify the mechanism for timing the needle bar and balance of the sewing machine with the feed dog.

Yet another object of the present invention is to eliminate the need for timing adjustment of the feed dog, needle bar and balance after assembly.

(Means for Solving the Problems) In the timing adjusting device between the needle bar, the balance and the feed dog of the sewing machine according to the present invention, the crank for the needle bar and the balance is fixed, and the timing adjusting device is provided at a predetermined angular position with respect to the crank. A horizontal upper shaft provided with a V-shaped groove extending in the longitudinal direction and a mechanism for imparting forward and backward movements to the feed dog are provided.
A mechanism that gives a forward and backward movement to the feed dog that has a cam fixed to the horizontal upper shaft by a set screw that extends in the groove, and a mechanism that gives a vertical movement to the feed dog. A first gear that is fixed to the cam or fixed to the horizontal upper shaft by another set screw that extends into the V-shaped groove, and that has a first timing mark at a predetermined position with respect to the crank; A vertical axis with two flats and a second gear with a second timing mark,
Fixed to the vertical shaft by a set screw that meshes with the first gear according to the timing mark and the second timing mark and that penetrates the second gear and engages with one of the flat portions. And a lifting cam fixed to the vertical shaft by a set screw that is a lifting cam and that penetrates the lifting cam and engages with another one of the flat portions. The two flat portions define a predetermined angular positional relationship between the second gear and the lifting cam.

(Operation) The needle bar and the crank for the balance are fixed to the horizontal upper shaft, and the cam is fixed to the horizontal upper shaft by the set screw extending in the V-shaped groove. By this, the timing between the movement of the needle bar and the balance and the movement of the feed dog in the front-back direction is automatically adjusted,
Moreover, since the set screw extends into the V-shaped groove,
This timing does not change after assembly.

If the first gear is not integrally fixed to the cam, the first gear is fixed to the horizontal upper shaft by a set screw extending into the V-shaped groove. As a result, the timing between the crank and the first gear is automatically adjusted. Moreover,
This timing does not change after assembly.

The second gear is fixed to one flat part of the vertical shaft with a set screw. Secure the lifting cam to the other flat of the vertical shaft with a set screw. Since the two flat portions have a predetermined angular positional relationship, the timing between the second gear and the lifting cam is automatically adjusted. Further, according to the timing mark of the second gear and the timing mark of the first gear,
By engaging the first and second gears, the timing between the crank and the lifting cam is automatically adjusted. As a result, the timing between the movement of the needle bar and the balance and the movement of the feed dog in the vertical direction is automatically adjusted, and further, the second gear and the lifting cam are vertically aligned by the set screws engaging with the flat portion. Since it is fixed to the shaft, the timing between them does not change after assembly.

(Embodiment) As shown by a dotted line in FIG. 1, the sewing machine 10 has a projecting arm 12, a machine pole 14 and a foundation 16. A horizontal upper shaft 18, which may be driven in a manner well known in the sewing machine art, is located in the overhang arm. The upper shaft 18 has a crank 20 fixed to one end thereof, and has a crank 20 for the needle bar 22 and the balance 24, and a bevel gear 26 and a cam 28 assembly fixed to the other end of the shaft. There is.

The needle bar 22 carries a needle 30, and the needle bar has a khank 20 and
A short shaft 32 fixed to the crank by a set screw 34,
A link 36 capable of swinging on the short axis and a needle bar collar 38 attached to the link provide a longitudinal reciprocating motion. The link 40 is pivotally attached at one end to the minor shaft 32 and, as shown, to one end of a link 44 which at its opposite end pivots about a defined axis 46 in the sewing machine. You are free. Upper shaft 18
If the link rotates, the link 40 is driven by the crank 20 and the motion is guided by the link 44.
40 gives reciprocating vertical movement to the balance 24.

The cam 28 of the gear and cam assembly provided at the end of the upper shaft 18 opposite to the crank 20 has a constant width, that is, it smoothly transitions from one side of the axis of the horizontal upper shaft 18 to its opposite side. Is formed as an eccentric cam having a constant width.
Above the cam 28 are teeth 4 of a sheet metal feed fork 52.
8, 50 straddle and these teeth have flanges as shown to form a large cam engaging surface. The pin 54 extends from the fork 52 into a sliding block 56 which is captured in a slide of a feed adjuster 58 pivotally mounted in the sewing machine 10. As shown, the feed adjuster
A feed adjuster lever 60 is pivotally attached to 58, which is actuated by a feed adjuster control assembly 62 to alter the tilt of the feed adjuster 58 and thus the advancement of the feed as is known in the art. It has become.

The lower end of the fork 52 is pivotally attached to the arm 68 of the rocking shaft 70 by a screw 64 and a nut 66, and the rocking shaft is a set screw.
It is supported by bullet centers 72,74 which are held in place in the frame of the sewing machine 10 by 76,78. The swing shaft 70 swings in response to vertical movement provided by a fork 52 connected to a sliding block 56 provided in a feed adjuster 58. The rocker shaft 70 has a pair of upright rocker arms 80,82 which are connected by screws 84,86 to opposite ends of a U-shaped feed dog carrier 88 of the sewing machine. A horizontally extending shelf 90 is formed on the feed dog carrier 88,
The feed dog 92 is attached to this shelf by screws 94 and 96. The feed dog 92 moves back and forth in the sewing machine bed 98 in response to the swing of the swing shaft 70.

A bevel gear 26 on the horizontal upper shaft 18 meshes with a bevel gear 100 located at one end of the vertical shaft 102. A lifting cam 104 and a toothed pulley 106 are attached to the opposite end of the vertical shaft 102. As shown, the cam 104 has a cam track 108 for receiving the driven member 110. The driven member is a lifting lever 112 pivotally attached to the bed of the sewing machine 10 at point 114.
Extends from one end. This lifting lever is driven member 11
Having a slotted hole as indicated by 118 at the end opposite 0,
It is adapted to receive a stud 120 protruding from the downwardly extending portion 122 of the U-shaped feed dog carrier 88. Vertical shaft 102, cam 104 and pulley 106 are bevel gears 26,00
And is rotated by the upper shaft 18 via. Pivoting movement of the lifting lever 112 is provided by the lifting cam 104 via the follower member 110, and actuation of the stud 120 by the lever provides up and down movement of the feed dog 92. The belt 124 on the pulley 106 is a thread taker (not shown).
Operatively connected to rotate the thread spooler. The pulley is suitably mounted on the vertical shaft 102 by screws 125 or the like.

The crank 20 is fixed to the upper shaft 18 by a spring pin 126, and the spring pin is press-fitted into alignment holes 128 and 132 formed in the crank and the shaft, respectively (FIG. 3). A longitudinally extending V-shaped groove 134 is formed in the upper shaft 18 at the end opposite the crank mounting end, and the shaft is provided with a set screw 136 having a conical tip extending into said groove to form the gear 26 and The cam 28 assembly is installed (Figure 4). If gear 26 and cam 28 are separately configured, each is secured by a set screw that extends into the V-shaped groove. The relative placement of the holes 132 and grooves 134 in the circumferential direction within the upper shaft 18 is predetermined to time the cam 28 and thereby the crank 20, needle bar.
The front-back movement of the feed dog 92 with respect to 22 and the balance 24 is timed.

The two adjacent teeth of the gear 26 extend inwardly and the timing marks 138, 140 are positioned at a predetermined angular position of the gear 26 relative to the crank 20 in the position where the gear 26 and cam 28 assembly is mounted.
Is formed. Gear 100 has a vertical axis with a set screw 142.
Fixed on a flat portion 144 provided on the upper end portion of 102 and has a raised timing mark 146 thereon, which mark on gear 26 when gears 26, 100 were first engaged during assembly of the sewing machine. Timing marks 138 and 1
It is located between 40 and. Lifting cam 104
Is a set screw 148 which allows a flat portion 150 at the lower end of the vertical shaft 102.
Is attached to. As a result, the contour of the lifting cam is angularly related to the gear 100 in a predetermined manner, and the reciprocating movement of the needle bar and the balance and the up-and-down movement of the feed dog are automatically timed with respect to the longitudinal movement of the feed tooth. To do.

(Effect of the invention) The cam of the mechanism that gives the forward and backward movement of the feed dog is fixed to the horizontal upper shaft by the set screw extending in the V-shaped groove at a predetermined angle position with the needle bar and the crank for the balance. Therefore, the timing between the movement of the needle bar and the balance and the movement of the feed dog in the longitudinal direction is automatically adjusted. Furthermore, this timing does not change after assembly.

A first gear of a mechanism that gives a vertical movement to the feed dog is integrally fixed to a cam or fixed to a horizontal upper shaft by a set screw extending in a V-shaped groove, and further, a second gear and a lifting cam. Are fixed to the two flat parts of the vertical shaft by set screws, respectively, and the first and second gears are meshed according to the timing mark of the second gear and the timing mark of the first gear, so that the needle bar And the timing between the movement of the balance and the movement of the feed dog in the vertical direction is automatically adjusted. Furthermore, the operation timing between them does not change after assembly.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a mechanism for driving a needle bar, a balance and a feed dog of a sewing machine according to the present invention, FIG. 2 is a perspective view of an upper shaft of a sewing machine, and FIG. 3 is a crank mounted on the upper shaft. FIG. 4 is an exploded perspective view showing a mode in which the gear and cam assembly is mounted on the upper shaft, and FIG. 5 is a perspective view showing the working connection between the upper shaft of the sewing machine and the feed dog. The development perspective view of the included vertical axis. 18 ... Horizontal upper shaft, 20 ... Crank, 22 ... Needle bar, 24 ... Balance, 26
... first gear, 28 ... cam, 92 ... feed tooth, 100 ... second gear, 102 ... vertical shaft, 104 ... lifting cam, 134 ... V-shaped groove, 1
38,140 ... first timing mark, 146 ... second timing mark, 144,150 ... flat part

Claims (1)

[Claims] 1. A timing adjusting device between a needle bar (22), a balance (24) and a feed dog (92) of a sewing machine, wherein the timing adjusting device is fixed to a crank (20) for the needle bar and the balance. Has been done,
A horizontal upper shaft (18) provided with a V-shaped groove (134) extending in the longitudinal direction at a predetermined angular position with respect to the crank.
And a mechanism that gives forward and backward movement to the feed dog (92),
A mechanism for imparting forward and backward movement to a feed dog having a cam (28) fixed to the horizontal upper shaft by a set screw (136) extending in the V-shaped groove (134); A mechanism for vertically moving the crank (20), which is fixed to the cam (28) or fixed to the horizontal upper shaft by another set screw extending in the V-shaped groove. A first gear (26) having a first timing mark (138,140) at a predetermined position relative to the vertical axis (102) having two flat portions (144,150), and a second timing mark (146). A second gear (100) provided, which is meshed with the first gear (26) in accordance with the first timing mark and the second timing mark, and which penetrates the second gear. Front by a set screw (142) that engages one of the flats (144) A second gear (100) fixed to the vertical shaft (102) and a set screw (148) which is used as a lifting cam and which penetrates the lifting cam and engages with another one (150) of the flat portions. Has a lifting cam (104) fixed to the vertical shaft (102) by the two flat portions (144, 150) of the second gear (100) and the lifting cam (104). A needle bar of a sewing machine, which defines a predetermined angular positional relationship between
Timing adjustment device between the balance and the feed dog.