US2985270A - Sewing machine drive - Google Patents

Description

May 23, 1961 J. D. LANDEROS SEWING MACHINE DRIVE 2 Sheets-Sheet 1 Filed March 21, 1958 Jose 0. Landeros 1N VEN TOR.

Mae/4 3a. BY MM 22% y 23, 1961 J. D. LANDEROS 2,985,270

SEWING MACHINE DRIVE Filed March 21, 1958 2 Sheets-Sheet 2 Jose 0. Landeros 1N VEN TOR.

nite States Patent SEWING MACHINE DRIVE Jose D. Landeros, 541 1 S. Main St., Los Angeles, Calif.

Filed Mar. 21, 1958, Ser. No. 722,926

14 Claims. (Cl. 19211) This invention relates in general to new and useful improvements in sewing machine construction, and more specifically to an improved drive for sewing machines.

At the present time substantially all sewing machines are powered by electric motors. These motors are controlled either by means of a rheostat or by means of a clutch. However, the present controls are such that not only is the starting and stopping of the sewing machine slow, which prevents accurate control of the sewing operation, but also it is difiicult for the operator of the sewing machine to obtain the desired speed.

It is therefore the primary object of this invention to provide an improved drive for sewing machines, the drive being of such a nature that the driving of the sewing machine is instantaneous upon the actuation of a control and at the same time the stopping of the drive of the sewing machine is instantaneous upon the releasing of the control.

Another object of this invention is to provide an improved sewing machine drive, the sewing machine drive being of such a nature that the speed of the sewing machine may be varied as desired by controlling the pressure exerted upon a foot pedal, the foot pedal controlling the engagement of the drive belt With a drive pulley and permitting continuous slippage between the drive spulley and drive belt, as desired.

Another object of this invention is to provide an improved drive for sewing machines, the drive being of a relatively simple construction whereby the manufacture thereof is economically feasible, and at the same time the drive being of such a nature that it may be readily mounted on existing and new machines with a minimum of modification.

A further object of this invention is to provide an improved drive for sewing machines, the drive including an idler pulley disposed remote from a driven pulley of the sewing machine, there being disposed intermediate the idler pulley and the driven pulley a drive pulley, the sizes of the driven pulley and the idler pulley relative to the drive pulley being such that the drive belt engaged over the driven pulley and the idler pulley normally is disposed closely adjacent to, but out of engagement with,

the drive pulley, there being provided suitable control means for moving the drive belt into frictional engagement with the drive pulley whereby a relative driving and slipping action occurs so that the pressure exerted upon the drive belt may be used to vary the speed with which the driven pulley is driven from the drive pulley.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout and in which:

Figure 1 is a fragmentary elevational view of a conventional type of sewing machine employing the drive which is the subject of this invention;

Patented May 23, 1961 Figure 2 is a fragmentary end view of the sewing machine of Figure l and shows further the relationship-of the various components of the invention with respect to the sewing machine; c

Figure 3 is an enlarged fragmentary vertical sectional view taken substantially upon the plane indicated by the section line 3-3 of Figure 2 and shows the specific mounting of the drive and a majority of the components thereof; a

Figure 4 is an enlarged fragmentary vertical sectional view taken substantially upon the plane indicated by the section line 44 of Figure 3 and shows further the details of a brake of the drive;

Figure 5 is a fragmentary vertical sectional view taken substantially upon the plane indicated by'the section line 55 of Figure 1 and shows the relationship between the idler pulley, the drive pulley, the drive belt and a belt tightening roller;

Figure 6 is a fragmentary exploded perspective View showing the details of a support'for' the drive and a spacing shim; and

Figure 7 is an enlarged exploded perspective view showing the cam members for effecting the release of the brake.

Referring now to the drawings in detail, it will be seen that there is illustrated in Figures 1 and 2 a conventional sewing machine assembly which is referred to in general by the reference numeral 10. The sewing machine assembly 10 includes a'bench ortable 12 which is supported by suitable legs' 14. Mounted on the top surface of the bench 12 is a conventional sewing machine unit which is referred to in general by the reference numeral 16. Among other conventional components, the sewing machine unit 16 includes a balance wheel 18 to which there is attached a driven pulley 20.

Secured to the underside of the bench 12 rearwardly of the sewing machine unit 16, as is best illustrated in V Figure 2, is a drive unit in the form of an electric motor 22. The electric motor 22 includes a base 24 which is secured to the underside of the bench 12 by means of bolts 26. The electric motor 22 also includes an armature shaft 28 which carries a drive pulley 30. The drive pulley 30 is aligned with the driven pulley 20.

Also carried by the bench 12 are the primary components of the drive, which are the subject of this invention, the drive being referred to in general by the reference numeral 32. The drive 32 includes a hanger, which is referred to in general by the reference numeral 34.

'The hanger 34 includes an upper horizontal part 36 and a depending part 38. The upper horizontal part 36 is provided with an elongated slot 40 which opens through the free end of the part 36. The slot 40 receives two of the bolts 26 mounting the electric motor 22 on the underside of the bench 12. In order to compensate for the mounting of the hanger 34, there is also provided a spacer 42 which corresponds to the horizontal part 36 and which is provided with an elongated slot 44. The spacer 42 is passed over the other two bolts 26 securing the motor 22 in place.

Referring now to Figure 3 in particular, it will be seen that the vertical part 38 of the hanger 34 is provided with a vertically elongated slot 46. The slot 46 has passed therethrough a bolt 48 which in turn carries a left, as viewed in Figure 3, by a collar 58 which is retained on the shaft 52 by means of a setscrew 60. The

idler pulley 56 is limited in its movement to the right by means of a cam assembly which is referred to in general by the reference numeral 62. Thus the idler pulley 56 is maintained in alignment with the drive pulley 30 and the driven pulley 20. It is to be noted that the drive pulley 30 is'disposed intermediate the driven pulley 28 and the idler pulley 56. It is also to be noted that the proportions of the idler pulley 56 and the driven pulley as compared to the drive pulley 30 is such that a drivebelt 64 entrained over the idler pulley 56 and the driven pulley 20 is normally disposed closely adjacent to, but out of contact with the drive pulley 30.

In order to assure the proper freedom of movement of the idler pulley 56, it is provided with a bushing 66. Extending through the idler pulley 56 and the bushing 66 is a bore 68 which has disposed in the inner part thereof a lubricating wick 70. The outer end of the bore 68 is closed by means of a setscrew 72.

The cam assembly 62 is part of a brake which is referred to in general by the reference numeral 74. The cam assembly 62 includes a female cam member 76 which is retained in place on the shaft 52 by means of a setscrew 78. 'The female cam member 76 also functions as a positioning collar for the idler pulley 56.

The cam assembly also includes a male cam member 80 which is rotatably journaled on the shaft 52. As is best shown in Figure 7, the female cam member 76 is provided in that end thereof which opposes the male cam member 80 with a cam slot '82 in which there is normally seated a projecting cam member 84 of the male cam member 80.

The right end of the male member 80 is provided with a polygonal cross-sectional extension 86. Engaged on the projection 86 and coupled to the male cam member 80 thereby is an intermediate part of a bell crank 88. The bell crank 88 is retained on the male cam member 80 by means of a thrust washer 90 which bears against both the projection 86 and the bell crank 88.

Disposed remote from the thrust washer 96 is a collar 92 which is retained in place on the right end of the shaft 52 by means of a setscrew 94. Extending between the collar 92 and the thrust washer 90 is a spring 96 which retains the bell crank 88 on the projection 86.

through a bore in the arm 100 and which is retained in an adjusted position by means of nuts 108 and 110 disposed on opposite sides of the arm 100.

Carried by the opposite end of the shaft. 102 in alignment with the drive belt 64 is a belt tensioning roller 112. The belt tensioning roller 112 is provided with bearings 1'14 mounting it on the shaft 182 and to assure the freedom of rotation thereof. The roller 112 is positioned by means of a collar 116 and a nut 118 disposed at opposite ends thereof.

As is best illustrated in Figures 3 and 4, carried by the male cam member 80 is a brake mounting plate 120 which is generally rectangular in outline. Secured to the brake mounting plate 120 is a pair of projecting brake shoes 122. The brake shoes 122 are of a length whereby the ends thereof engage the idler pulley 56 and prevent rotation thereof when the cam assembly 62 is in its inoperative position, as is illustrated in Figure 3. The plate 120 is secured on the male cam member 80 by means of a setscrew 124.

The legs 14 at opposite ends of the bench 12 have lower portions thereof connected together by transverse frame members 126. Extending between the transverse frame members is the longitudinal bar 128. Secured to the right portion of the bar 128 is a hinge-130 which carries a foot pedal 132. The foot pedal 132 is connected to the arm 98 by means of the link 134.

The connection between the hanger 34 and the support 50 is such that the idler pulley 56 may be properly aligned with respect to the driven pulley and the drive pulley. 30' whereby the drive belt 64 is disposed closely adjacent the drive pulley 30, but out of engagement therewith, and at the same time the drive belt 64 is properly tensioned.

It is to be understood that during the general use of the sewing machine construction 10, the electric motor 22 will run continuously. When it is desired to actuate the sewing machine unit 16, the foot pedal 132 is depressed with the result that the bell crank 88 is pivoted. The pivoting of the bell crank 88 simultaneously results in the releasing of the brake 74 and the movement of the drive belt 64 into engagement with the drive pulley 38. The brake 74 is released by the rotation of the male cam member which results in the movement of the male cam member 80' to the right. Movement of the .male cam member 80 to theright, of course, results in movement of the brake shoes 122 to the right and out of engagement with the idler pulley 56 so that the idler pulley 56 is free to rotate.

The pivoting'of the bell crank 88 also results in'the movement of the belt tensioning roller 112 into engagement with the belt 64 closely adjacent to the drive pulley 30 and thus the movement of the belt 64 into frictional engagement with the drive belt 30. By varying the pressure contact between the drive belt 64 and the drive pulley 30, slippage may be controlled and thus the speed of rotation of the driven pulley 20 may be controlled. By increasing the downward pressure on the foot pedal 132, the speed of the sewing machine unit 16 may be increased .as is desired. Furthermore, as soon as the pedal 132 is released, the male cam member 80 will rotate back to its original position at which time the brake shoes 122 will again engage the idler pulley 56 immedi ately stopping the rotation of the idler pulley 56. This, of course, will stop the driving of the drive belt 64 causing the stopping of the sewing machine unit 16..

From the foregoing description of the present invention, it will be seen that the drive 32 is of such a nature that the response to the actuation thereof by the depressing of the foot pedal 132 is instantaneous. Further, the speed at which the driving machine unit 16 is driven may be readily varied by the operator of the sewing machine construction 10 by the pressure exerted on the foot pedal 132. Further, as stated above, when the foot pedal ,132 is released, the driving of the sewing machine unit 16 is immediately discontinued.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows: 7

1. A drive unit for sewing machines and the like having a driven pulley, said drive unit comprising a fixed power source having a drive pulley aligned with said driven pulley, an idler pulley disposed in alignment with said driven pulley and said drive pulley, said drive pulley being disposed intermediate said driven pulley and said idler pulley, a drive belt entrained over said driven pulley and said idler pulley, at least one of said driven pulley and said idler pulley being of an effective diameter larger than the effective diameter of said drive pulley whereby said drive belt is normally out of engagement with said drive pulley, means engageable with said drive belt to move said drive belt into driven engagement with said drive pulley, brake means selectively movable into and out of engagement with a side of said idler pulley for stopping overriding movement of said drive belt when said drive belt moves out of engagement with said drive pulley.

2. A drive unit for sewing machines and the like having a driven pulley, said drive unit comprising a fixed power source having a drive pulley aligned with said driven pulley, an idler pulley disposed in alignment with said driven pulley and said drive pulley, said drive pulley being disposed intermediate said driven pulley and said idler pulley, a drive belt entrained over said driven pulley and said idler pulley, at least one of said driven pulley and said idler pulley being of an eifective diameter larger than the effective diameter of said drive pulley whereby said drive belt is normally out of engagement with said drive pulley, means engageable with said drive belt to move said drive belt into driven engagement with said drive pulley, brake means selectively movable into and out of engagement with a side of said idler pulley for stopping overriding movement of said drive belt when said drive belt moves out of engagement with said drive pulley, and a common control for said first mentioned means and said brake means.

3. A drive unit for sewing machines and the like having a driven pulley, said drive unit comprising a fixed power source having a drive pulley aligned with said driven pulley, an idler pulley disposed in alignment with said driven pulley and said drive pulley, said drive pulley being disposed intermediate said driven pulley and said idler pulley, a drive belt entrained over said driven pulley and said idler pulley, at least one of said driven pulley and said idler pulley being of an effective diameter larger than the effective diameter of said drive pulley whereby said drive belt is normally out of engagement with said drive pulley, means engageable with said drive belt to move said drive belt into driven engagement with said drive pulley, brake means releasably connected to said idler pulley at the side thereof for stopping overriding movement of said drive belt when said drive belt moves out of engagement with said drive pulley.

4. A drive unit for sewing machines and the like having a driven pulley, said drive unit comprising a fixed power source having a drive pulley aligned with said driven pulley, an idler pulley disposed in alignment with said driven pulley and said drive pulley, said drive pulley being disposed intermediate said driven pulley and said idler pulley, a drive belt entrained over said driven pulley and said idler pulley, at least one of said driven pulley and said idler pulley being of an effective diameter larger than the effective diameter of said drive pulley whereby said drive belt is normally out of engagement with said drive pulley, means engageable with said drive belt to move said drive belt into driven engagement with said drive pulley, brake means releasably frictionally connected to said idler pulley at one side thereof for stopping overriding movement of said drive belt when said drive belt moves out of engagement with said drive pulley, and a common control for simultaneous but opposite operation of said first mentioned means and said brake means.

5. A drive unit for sewing machines and the like having a driven pulley, said drive unit comprising a fixed power source having a drive pulley aligned with said driven pulley, an idler pulley disposed in alignment with said driven pulley and said drive pulley, said drive pulley being disposed intermediate said driven pulley and said idler pulley, a drive belt entrained over said driven pulley and said idler pulley, at least one of said driven pulley and said idler pulley being of an effective diameter larger than the effective diameter of said drive pulley whereby said drive belt is normally out of engagement with said drive pulley, a belt tensioning roller disposed adjacent said drive pulley and engageable with said outer surface of said drive belt, and means connected to said belt tensioning roller for moving said belt tensioning roller into frietional engagement with said drive belt and said drive belt into frictional engagement with said drive pulley, brake means selectively movable into and out of engagement with a side of said idler pulley for stopping overriding movement of said drive belt when said drive belt moves out of engagement with said drive pulley.

6. .A drive unit for sewing machines and the like having a driven pulley, said drive unit comprising a fixed power source having a drive pulley aligned with said driven pulley, an idler pulley disposed in alignment with said driven pulley and said drive pulley, said drive pulley being disposed intermediate said driven pulley and said idler pulley, a drive belt entrained over said driven pulley and said idler pulley, at least one of said driven pulley and said idler pulley being of an effective diameter larger than the effective diameter of said drive pulley whereby said drive belt is normally out of engagement with said drive pulley, a belt tensioning roller disposed adjacent said drive pulley and engageable with said outer surface of said drive belt, and means connected to said belt tensioning roller for moving said belt tensioning roller into frictional engagement with said drive belt and said drive belt into frictional engagement with said drive pulley, brake means selectively movable into and out of engagement with a sideof said idler pulley for stopping overriding movement of said drive belt when said drive belt moves out of engagement with said drive pulley, means co'nnecting said first mentioned means to said brake means for controlling the operation of said brake means.

7. A drive unit for sewing machines and the like having a driven pulley, said drive unit comprising a fixed power source having a drive pulley aligned with said driven pulley, an idler pulley disposed in alignment with said driven pulley and said drive pulley, said drive pulley being disposed intermediate said driven pulley and said idler pulley, a drive belt entrained over said driven pulley and said idler pulley, at least one of said driven pulley and said idler pulley being of an eflfective diameter larger than the effective diameter of said drive pulley whereby said drive belt is normally out of engagement with said drive pulley, a belt tensioning roller disposed adjacent said drive pulley and engageable with an outer surface of said drive belt, and means connected to said belt tensioning roller for moving said belt tensioning roller into frictional engagement with said drive belt and said drive belt into frictional engagement with said drive pulley, brake means engaged with said idler pulley and including a pair of axially extending friction plates movable axially into engagement with one side of said idler pulley for stopping overriding movement of said drive belt when said drive belt moves out of engagement with said drive pulley.

8. A drive unit for sewing machines and the like having a driven pulley, said drive unit comprising a fixed power source having a drive pulley aligned with said driven pulley, an idler pulley disposed in alignment with said driven pulley and said drive pulley, said drive pulley being disposed intermediate said driven pulley and said idler pulley, a drive belt entrained over said driven pulley and said idler pulley, at least one of said driven pulley and said idler pulley being of an effective diameter larger than the effective diameter of said drive pulley whereby said drive belt is normally out of engagement with said drive pulley, a belt tensioning roller disposed adjacent said drive pulley and engageable with an outer surface of said drive belt, and means connected to said belt tensioning roller for moving said belt tensioning roller into frictional engagement with said drive belt and said drive belt into frictional engagement with said drive pulley, brake means engaged with said idler pulley for stopping overriding movement of said drive belt when said drive belt moves out of engagement with said drive pulley, means connecting said first mentioned means to said brake means for controlling the operation of said brake means.

9. The combination of claim 1 wherein said brake means is directly engageable with a side of said idler pulley upon diametrically opposite portions thereof.

10. The combination of claim 1 including an axle upon 7 '3' which said idler pulley is rotatably journaled, said brake means including a member movable axially upon said axle and having po'rtions directly engageable with a side 9 of said idler pulley.

11. The combination of claim 1 including an axle upon which said idler pulley is rotatably journaled, said brake means including a member movable rotationally upon said axle and having portions directly engageable with a side of said idler pulley, said first means including a lever mounted on said member and rotatable in unison therewith, means for actuating said lever.

12. The combination of claim 1 including an axle upon which said idler pulley is rotatably journaled, said brake means including a member movable rotationally upon said axle and having portions directly engageable with at with a side of said idler pulley, said portions comprising plates on opposite sides of said axle engageable with the side of said idler pulley. I p

1 4. The combination of claim 1 including an axle upon which said idler pulley is rotatably journaled, said brake means including a member movable upon said axle and having portions directly engageable with a side of said idler pulley, said first means including a lever mounted on said member and rotatable in unison therewith, means for actuating said lever, and a belt tensioning roller journaled on said lever and directly engageable with said belt, said lever having a cantilever shaft projecting laterally to one side thereof, said tensioning roller being journaled on said shaft and extending into alignment with said belt, driving and driven pulleys.

References Cited in the file of this patent UNITED STATES PATENTS 656,853 Noble Aug. 28, 1900 1,301,849 Jones Apr. 29, 1919 2,195,229 Smart Mar. 26, 1940 2,739,552 Sailer Mar, 27, 1956

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