US2489584A

US2489584A - Clutch and brake for sewing machines or the like

Info

Publication number: US2489584A
Application number: US748558A
Authority: US
Inventors: Robert G Miller
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-05-16
Filing date: 1947-05-16
Publication date: 1949-11-29
Anticipated expiration: 1966-11-29

Description

R. G. MILLER Nov. 29, 1949 CLUTCH AND BRAKE FOR SEWING MACHINES OR THE LIKE 2 Shets-Sheet 1 Filed May 16, 1947 INVENILOR R0 BERT G. M 1 1.1.5.9; Hymn- A ATTORNEYS Nov. 29, 1949 R. G. MILLER CLUTCH ANDBRAKE FOR SEWING MACHINES OR THE LIKE 2 Sheets-Sheet 2 Filed May 16, 1947 mm L mm m n m W D lG m? T m? R mm 0 I .NN mN R 0 2. 9 S B Pm mm NM Om mm vm NN 4 0 mm N .NN

llllll-Illl II I mm mm 3 5. 5

Pm ll mm ATTORNEYS.

Patented Nov. 29, 1949 UNITED STATE S PATENT OFFICE CLUTCH AND BRAKE FOR SEWING MACHINES OR THE LIKE My invention relates to a clutch for power driven sewing machines, and the like.

A primary object of the invention is to provide a clutch adapted to change standard fractional horsepower electric motors into drives for power driven sewing machines.

A further object of the invention is to provide a clutch and actuating means therefor, to be mounted directly upon the sewing machine motor, to form with the motor a self contained drive unit for the machine.

A further object is to provide a device of the above mentioned character which is simple in design, comprising few parts, and therefore quite inexpensive to manufacture.

A still further object is to provide a clutch device for sewing machines, which when assembled onto the drive motor provides an extremely compact power unit, adapted to be mounted so as not to interfere with the operator of the machine.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this application, and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a side elevation of a sewing machine clutch embodying my invention, the same being applied to a motor disposed beneath a sewing machine table, parts broken away,

Figure 2 is an enlarged side elevation of the clutch, similar to Figure 1, parts in section and parts broken away.

Figure 3 is a bottom plan view of the clutch and motor, parts broken away,

Figure 4 is an end elevation of the same, parts omitted,

Figure 5 is a vertical section taken on line 55 of Figure 2, and,

Figure 6 is a vertical section taken on line 6-6 of Figure 2.

In the drawings, where for the purpose of illustration is shown a preferred embodiment of my invention, the numeral ill designates a horizontal table or platform, spaced above a floor II, and. upon which is securely mounted a conventional power driven sewing machine l2. This sewing machine l2 has the usual rotatable hand wheel l3, mounted upon the horizontal drive shaft of the machine for rotation therewith; and rigidly secured to the outer side of the hand wheel is the usual grooved pulley I4, for driving the horizontal shaft of the machine.

The clutch disc is provided with an annular. groove 28 formed in its outer vertical face, and near its outer periphery; and this groove receives;

l? for driving the machine. The armature shaft 18 of this motor is disposed horizontally, and in-- cludes the usual axial extension l8 at one end.

This shaft extension I8 is dis-- posed beneath the grooved pulley H4. The motor of the motor.

illustrated is of the type having a casing comprising three casing sections, a middle or main casing section l9, and end casing sections 20 and 2!. These casing sections are fastened together by a plurality of equally spaced axial throughf bolts 22 and 22 carryingnuts 23.

Rigidly mounted upon the armature shaft ex-f tension 8, for rotation therewith, by meansof= a set screw 24, or the like, is a fly wheel or clutch disc 25, having a hub 26.

integral with the hub'26. This tubular extension 21 extends substantially to the. outer'end of the shaft extension i8 and encloses the same.

an annular clutch element or ring 29, preferably formed of leather. The clutch ring 29 is securely held within the groove 28 by any suitable means, and cannot slide within the groove. The outer annular surface of the leather clutch ring 29'.

projects axially beyond the outer vertical face of the clutch disc to provide a frictional clutch surface, see Figure 2.

Rotatably mounted upon the tubular extension 21 of the clutch disc, and free to be shifted axiallythereon, is an intermediate sleeve or bushing 33, including a curved outer end 3|. This bushing 30 extends axially outwardly beyond the end of the armature shaft extension l8 for a short distance.

Mounted upon the bushing30 and adapted to rotate therewith is a combined pulley and clutch disc32. This element 32 includes an elongated tubular hub 33, to receive the bushing 38 and the hub and bushing are rigidly secured together by a set screw 34, or the like. The combined pulley.

and clutch disc 32 has a flat vertical inner face 35 for engagement with the leather clutch ring 29, and is provided with an annular brake groove 36, formed in its outer periphery. The groove 36 is rectangular in transverse cross section. The' combined pulley and clutch disc further includes- 4 a grooved pulles extension 31, formed integral The clutch disc 25 is disposed at the inner end of the shaft eXten-- sion I8, and includes an outwardly axially pro jecting tubular extension or bearing 21, formed therewith, and having an outside diameter smaller than the diameter of the face 35. The outside diameter of the element 32 is preferably substantially the same as the outside diameter of the clutch disc 25. The pulley extension 37 is disposed axially outwardly of the brake groove 36, see Figure 2, and is in substantial vertical alignment with the grooved pulley 14. The numeral 38 designates a belt which engages in the grooves of the pulley I4 and pulley extension 37.

Rigidly mounted upon the casing section 2i of the motor I! is a generally cross-shaped adaptor bracket 39. This bracket includes an elongated.

horizontal arm 49, parallel to the armature shaft l8, and offset laterally to one side of the longitudinal center line of the armature shaft, see Figure 5. The horizontal arm 49 is disposed beneath the armature shaft extension it and the elements mounted thereon, and its outer end ii projects outwardly beyond the end 3! of the bushing 39. The arm 40 is provided with a longitudinal slot 42, near its outer end. The adaptor bracket 39 further includes upwardly curved arms 43 near its inner end, and formed integral with the horizontal arm 40. These arms 43 are disposed upon opposite sides of the arm 4t, and extend laterally and upwardly from such arm. The upper ends of the curved arms 43 carry apertured' bosses or sleeves 44, formed integral therewith, and these bosses are disposed adjacent to the through bolts 22' of the motor casing. These 7 through bolts 22', adjacent to the bosses 54, are

longer than the outer through bolts 22, and they extend through the apertures in the bosses. A pair of the nuts 23 are employed for rigidly clamping the bosses 44 against the casing section 25. The bracket 39 further includes a horizontal foot 45,, integral with the arm 49, and extending inwardly axially beyond the arms 43 to engage beneath the end casing section 2|. The foot :25 counteracts bending moment imparted to the arm 40 during the operation of the clutch, and. thereby makes the bracket 39 extremely rigid. The bracket 39 is also provided with an apertured ear 46, depending from the arm 40, and adjacent to the curved arms 43.

' Pivotally connected to the adaptor bracket 39 by means of a bolt 41, is a bell-crank lever 48. This bell-crank lever includes a substantially vertical upstanding arm 49, provided at its upper end with a head 50, having a screw threaded opening for receiving an adjusting screw 52, carrying a lock nut 53. The length of the arm 49 is such that the adjusting screw 52 is disposed substantially at the axial center line of the armature shaft l8. The adjusting screw 52 is adapted to engage the end 3| of the bushing 39., lower portion of the upstanding arm 49 is pro.-.

vided with an opening 49, to. pivotally receivev the smooth shank 59 of the pivot bolt 41'. The diameter of the opening 49' is.greater than the width of the slot 42 in the arm 4%,.and the smooth,

shank 59' forms a lateral shoulder 51' for engagement against the adjacent side ofthe lever 40. A nut 52 is mounted upon the reduced screw threaded portion 53 of; the pivot bolt. and.c1amps.

the arm 49 against the shoulder'5li". It is thus seen that the bell-cranklever 48,is freely pivotallymounted upon the smoothshank portion 58', and;

the bolt s? is fixed with respect to the arm 49 of; the adaptor bracket 39; The bolt 4? may be adjusted longitudinally of the slot d2 asrequired: The:

bell-crank lever 48 further includesasubstantially horizontal arm 54, including a portion 54", adjacent to the arm 49,- anddisposedat the longi- The.

tudinal center line of the armature shaft 18. The portion 54 carries a vertical extension 55, having an ofiset horizontal shoulder 56, provided with a recess 51, for holding a brake element 58. The brake element 58 is adapted to enter the annular brake groove 36, and the width of this groove is greater than the width of the brake element. The horizontal arm 54' further includes a downwardly offset generally horizontal portion 59, extending axially of the motor I! and beneath the same, and the portion 59 terminates near the longitudinal center of the motor. The portion 59 is provided with an apertured ear 69, disposed below and inwardly of the car 45. A retractile coil spring 6| has its ends connected with the ears 46 and 60, and tends to maintain the horizontal arm 54' in the upper position. The inner end of the arm portion 59 has an opening 62, pivotally receiving the end of a tension rod 63, extending downwardly near the floor H. The lower end of, the rod 63 is pivotally connected to a foot pedal 64, in turn pivotally connected to a fixed bracket 65. A compressible coil spring 66 may be arranged beneath the foot pedal 64 to resist the downward movement of the same.

In operation, the electric motor ll may operate continuously, and the clutch disc 25 rotates with the armature shaft 98. When it is desired to drive the sewing machine, the operator depresses the foot pedal 65. When this is done, the rod 63 exerts a downward pull upon the arm 54, and this arm is swung downwardly, Figure 1, against the force of the spring 6|. When this occurs the brake element 58 disengages the bottom of the annular groove Ssto free the combined pulley and clutch disc 3?. for rotation. Simultaneously, the arm 49 of the bell-crank lever swings to the right, Figure 2, and the screw 52 engages the end 31 of the bushing 39. This bushing is shifted axially inwardly upon the hub 21, and the combined pulley and clutch disc 32 is shifted with the bushing. The face 35 of the element 32 engages against the clutch ring 29 and this causes the element 32 to rotate with the armature shaft. The clutch engagement will be maintained as long as the operator depresses the foot pedal 94. When the element 32 is thus driven, the pulley extension 3? drives the belt 33, driving the pulley I4 of the sewing machine.

When it is desired to stop the sewing machine the operator removes her foot from the pedal 64. When this occurs the spring 9| swings the arm 55" upwardly. The arm 49 swings to the left, Figure 2, and the combined pulley and clutch disc 32 disengages the clutch ring 29 and is no longer driven thereby. Simultaneously, the brake element 58 moves upwardly, Figure 2, and engages the bottom of the groove 35 to hold the element 32 against rotation. The brake element 58 also prevents axial movement of the element 32 with respect to the armature shaft H3. The pulley i4 is now prevented from rotating, and the sewing machine is stopped.

It is to be understood that the form of my invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size, and arrangement of parts may be resorted to without departing from the spirit of my invention or the scope of the subjoined claim.

Having thus described my invention, what I claim is:

In a friction clutch drive mechanism, an electric motor including a horizontal casing and a horizontal armature shaft extending outwardly beyond one end of the casing, means secured to the top of the casing to attach the same to a support, driving and driven rotary elements mounted upon the armature shaft outwardly of and near one end of the casing, one element being axially movable, a horizontal bracket including a single longitudinal arm, a single transverse arm provided at its ends with openings, and a longitudinal foot, the longitudinal arm and foot being arranged near the longitudinal center of the transverse arm and upon opposite sides of the transverse arm, the longitudinal arm being disposed beneath the rotary elements and the openings of the transverse arm receiving bolts from the casing and the foot engaging the bottom of the side of the casing below the bolts, a bell crank lever including a generally horizontal longitudinal arm and an upstanding arm projecting above the longitudinal arm, the upstanding arm serving to move the axially movable element, the generally horizontal lever arm being arranged beneath the casing and rotary elements, means pivotally connecting the outer ends of the generally horizontal lever arm and longitudinal REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 909,631 Marx Jan. 12, 1909 1,510,728 Webb Oct. 7, 1924 1,647,450 Katzman Nov. 1, 1927 2,048,501 Goosman July 21, 1936 FOREIGN PATENTS Number Country Date 420,708 Great Britain Dec. 6, 1934