US1792818A

US1792818A - Sewing-machine-motor controller

Info

Publication number: US1792818A
Application number: US240587A
Authority: US
Inventors: Daniel H Chason
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1927-12-16
Filing date: 1927-12-16
Publication date: 1931-02-17
Anticipated expiration: 1948-02-17

Description

Feb; 17, 1931. D. H. CHASON SEWING MACHINE MOTOR CONTROLLER Filed Dec. 16, 1927 2 Sheets-Sheet l TOR INVEN M J N ts WITNESSES Feb. 17, 1931. D. H CHASON 1,792,818

SEWING MACHINE MOTOR CONTRGLLBR Filed Dec. 16, 1927 2 Sheets-Sheet 2 INVENTOR 1.3V 4 M ii ATTORNEY Patented Feb. 17,1931

UNITED s ATEsPATENr OFFICE DANIEL H. crmson, onnniznnnrmivnw JEBSEYQASSIGNOR TO THE, SINGER MA U- to the various arts, the sewing Ina'chinehas rncrunme COMPANY, JERSEY .,sEwINenvrAcnnvn-Moron CONTROLLER Application filed December 16,1927. Serial No. 2 10,5875- In the widespread application of electricity received its share of attention, and various devices for the electric drive and-control of sewing machines have "been-made and used. WV'hile the growing demand is for the complete, factory equipped,*electric sewing machine, there are in use large numbers of treadle-driven sewing machines which only await the advent of a conveniently applicable and usable form ofmotor and motorcontroller to convert them into electric machines; There ha'slalready been provided'a sewing machine motor adapted forattac hment to the well-known family sewing ma chine so as to become, in effect,- a permanent fixture or part of the machine, not requiring to'be removed or shifted when the machine is to be put away or made ready for use. I refer to the electric sewing machinedescribed in the U. S. patent to Diehl and Hemleb No. 1,488,234 of March25,1924. V v

The usual sewing machine motor-controllers are of three types, 'viz.,' hand-operated, knee-operated and foot-operated. Thehandoperated controller is little used as it inter feres more or less with theuse of the operators hands in presenting and guiding the work to the sewing machines. The kneeoperated controller is in more general favor, and there is practically no ob ect1on to the foot-operated controller in-so-far-as the broad principle of foot-operation is concerned. Foot-controllers, such as heretofore coinmonly provided, have however been of the portable type comprising a pedal-operated rheostat adapted to rest upon the floor adiacent the sewing machine table. The difficulty with-this type of foot-controller is that it has a tendency to creep or shift its position- Furthermore, it cannot be placed in a position for convenient operation,-for the reason that the treadle-plate element of the sewing machine'l table occupies the floor space where the footcontroller would be of most convenient access to the operators foot and where it would be least likely to manifestits creeping tendency.

V In the ordinary drop-head sewing machine, as converted to an electric sewingmachine by the application of an electric-motor and foot-controller, the treadle mechanism of-the sewingmachine stand has nofunction' except as a potential foot-power drive and, as above stated, thetreadle-plate is in theway ofconvenient location of the foot-controller;

With the idea of using the'conveniently accessible and operable treadle-plate as a means for operating them-otor-controller, it has been proposed to mount the-motor-controller or rheostat onthesewing machine table and connect it by a pull-rod to the treadle-plate,

but none'of the devices heretofore proposed fills the long-felt want for a tread'le-plate opdependable construction and ofneatand inconspicuous appearance.

The present-invention has for an object or; ELIZABETH, NE-W JERSEY, A conronnrron or NEW to provide a motor-controller to fill the want 7 referred to and enable the well-known treadle-driven family sewing machineto be readilyconverted into an electric machine. a

Further objects of the-invention will appear r in the following description and claims.

According to the present improvement the motor controller is in the form of a rheostat having an operatingpull-rod with a straight or direct pull treadle-eonnection, avoiding the use'of cams, levers,r'ock-shafts, etc., both within and outside of the rheostat casing, and reducing the operating mechanism to the simplest form. The rheostat is mounted within a casing one flat side face of which has secured thereto the concave side of a special longitudinally troughed bracket which clampsbetween it and said side face, an upwardly extending arm at 'a corner of the central rectangular portion of the brace-member for the legs of the ordinary cast-iron sewing machine stand. The bracket is formed at its lower end with divergent legs extending beyond the casing and having feet bent toward the plane of the side face of the rheostat casing and adaptedto rest against the upper horizontal rib and one end-rib of the central rectangular member of the brace.

In the accompanying drawings, Fig. 1 is a front side elevation of the usual family sewing machine as converted to an electric machine in accordance with the invention. Fig 2 is a rear side elevation of: the motor-controller as mounted on the brace-member of the sewing machine stand; the controllercover being removed. Fig. 3 is a section on the line 3-3, Fig. 1. Fig. l is a perspective view of the bracket-member which cooperates with the controller casing to hold the controller clamped to the brace-member oi the sewing machine stand. Fig. 5 is a central transverse vertical section through the sewing machine stand. Fig. 6 is a' section on the line 66, Fig. 1. Fig. 7 is a detail view of the crank-strap or upper pitman-section used for foot-power drive. Fig. 8 is the rheostat pull-hook or second upper pitman-section used for electrical operation, and Fig. 9 is the lower-pitman-section which is selectively connectible to either of the sections shown in Figs. 7 and 8.

Referring more particularly to Fig. 1. 1 represents the usual drop-head sewing machine table or stand having a wooden top 2 carrying the sewing head A. The top 2 is supported by the reticulated or ribbed cast-- iron end legs 3 connected by an intermediate ribbed cast-iron brace-member l pivot-ally carrying the usual reticulated treadle 5. The ribs of the brace-member e are shown in 1. The brace-member is formed with a central rectangular portion 6 from the corners of which extend arms 7 secured to the legs 3. The brace-member 4 has mounted thereon and attached to the usual treadle-plate 5 a crank-shaft 8 carrying a belt-wheel 9 which, for foot-power operation, is connected by the belt 10, Fig. 1, to the usual grooved balancewheel 11 of the sewing machine.

The crank-shaft 8 is embraced by the crankstrap 12 which, for foot-power operation is connected to the usual trea dle-rod or pitinan 13, as shown in Fig. 5; the crank-strap constituting, in efiect, an upper pitman-section or extension 01 the pitman 13. The pitman 13 has the usual ball-and-socket connection 14 with the. treadle-plate 5 and is threaded at 15 at its upper end to screw into the threaded socket 16, Fig. 7, oi. the crankstrap 12.

For electrical operation, the belt is removed from the balance-wheel 9 and a motor 17. such for example as that shown in said Diehl and Hemleb patent. is applied to the sewing head andconnected by a belt 18 to the balance-wheel 11. The motor 17 is connected to the source of electrical energy by the supply cord 19 in series with the cord 20 leading to the motor-controller 21. which, in the present instance, is a variable resistance device mounted on the brace-member 4 and including an operating pull-rod 22 to the apertured lower end of which is connected a hook 23 having the threaded socket 24, Fig. 8 for reception of the threaded end 15 of the pitman rod 13. As thus directly connected for electrical operation, pressure upon the trcadleplate 5 effects a downward sliding movement of the pull-rod 22, which effects a variation of the resistance in the motor circuit and enables the speed of the motor 17 and machine A to be nicely controlled.

The motor-controller comprises a base 25 from one end of which rises an end-wall 26 having a slot through which passes the pullred 22 connected at its inner end to the U-shaped member 27, the ends 28 of the legs of which are directed toward one another but spaced apart. Recovery-springs 29 serve to restore the pull-rod 22 to initial or non-running position with the ends 28 contacting with the stop-pins 30. The pull-rod 22 is formed with shoulders 22 which act as a stop by striking the end-wall 26 and limiting the motion of the pull-rod 22 in a direction to compress the springs 29. Mounted on the base 25 independently of the pull-rod 22 and recovery-spring mechanism is the compression rheostat unit having the usual porcelain body 31 formed with spaced wells or chambers 32 for the stacks of carbon resistance disks 33which substantially fill the wells 32 and are electrically connected to the terminals 34. The stacks 33 also comprise the compression heads 35 which are bridged by the bow-spring contactmember 36 backed by a stiiler spring-member 37 substantially in accordance with the disclosure of the patent to D. H. Chasou, No. 1,643,292 of Sept. 27, 1927. From the center of the bow-spring 36 there extends in line with the pull-rod 22 a second pull-rod 38 having a screw-threaded end carrying an adjustable nut 39 whose shank passes through the space between the ends 28 of the U-shaped member 27. A. recovery-spring 4.0 surrounding the rod 38 is disposed between the body 31 and the bow-spring 36. The nut 39 is so adjusted that the bow-spring will be carried out of contact with the pressureheads 35 by the spring 40 when the springs 29 are holding the members 28 in engagement with the stops 30. The various parts on the base 25 are enclosed within a suitable casing 11.

The rheostat is secured to one of the arms 7 of the brace-member 4; by means of a special clamp having a trough-shaped body 42 formed at its upper end with oppositely extended arms .13 secured by screws to the flat side face of the rheostat base 25, so as to clamp the brace-member 7 to such base. The body 12 of the clamp is formed at its lower end with divergent legs 44 having feet 15 bent toward the plane of the base 25 so as to rest against the upper horizontal rib and one end rib of the central rectangular portion 6 of the brace 4.

By mounting the controller 21 on the brace member 4, and particularly in rear of such brace-member, it is located in a position where its connection withthe usual treadlepitman may be effected with great simplicity. Still further, it is not in a conspicuous position and, together with the cord 20, is well off of the floor and out of the way.

Having thus set forth the nature of the invention, what I claim herein is V V 1. A sewing machine motorcontroller comprising a casing, a pull-rod extending through said casing, recovery-spring means in said casing connected to said pull-rod, co-

' acting stops associated with said pull-rod tion adapted to clasp between it and said casing one of the upwardly extending arms of the brace-member of the ordinary castiron sewing machine stand, said bracket also having diverging legs at the lower end of said body-portion, said legs having feet serving as rests in contact with the horizontal and vertical edges of the rectangular central portion of said brace-member.

3. The combination with the brace-member for the legs of the ordinary cast ironsewing machine stand, said brace-member having an intermediate rectangular frame-portion and arms at the corners of said rectangular frame-portion, of a rheostat having a casing formed with a side face, a treadle-operated pull-rod controlling the rheostat, and a bracket having a longitudinally troughed body-portion embracing one of the arms of 7 said brace-member, means at one end of said body-portion securing said bracket to said rheostat casing side-face with the arm of the brace-member clamped therebetween, said bracket having a pair of diverging legs at the other end of said body-portion, said legs extending beyond the rheostat casing and having feet resting against one horizontal abnormal stresses accidentally applied to-said treadle-plate.

5 The combination with a sewing machine table having a treadle-plate, of a motor-controller comprising 'a resistance-unit having relatively delicate operating mechanism, a relatively strong direct-pull connection between said treadle-plate and said relatively weak resistance operating mechanism, and a stop'cooperating with an element of said relatively strong direct-pull connection to safely take any abnormal strains applied to the treadle and prevent transmission of such strains to the resistance unit.

In testimony whereof, I have signed my name to this specification.

' DANIEL H. CHASON.

and one vertical edge of the rectangular frame-portion of said brace-member.

4. a The combination with a sewing machine table havlng a treadle-plate, of armotor-con troller comprising a compression resistance unit and operating pull-rod, a direct-pull operating connection extending from said treadle plate to said operating pull-rod and a stop cooperating with an element of said operating connection for preventing the transmission to said resistance unit of any