US3408882A - Motor treadle handwheel - Google Patents

Description

Nov. 5, 1968 E. w. BIALY 3,408,882

MOTOR TREADLE HANDWHEEL Filed Oct. 27; 1966 INVENTOR. Edward W. Bialy 479411 7% ATTORNEY United Stews P ts .0

' 3, ,3 J, MOTQR TREADLE' HANDWHEEL Edward W. Bialy, lli llsid e,"l \lJ., assignor t'o'The Singer :Cdr'npany', ew York,"N.Y'.'. "a" corporation of New Jersey i I FildOct. 27,1966, Ser- No}- 590,078 3'laimS.1'(Cl'. 74-625) This invention improves on-the apparatus of US. Patent No. 3,224,398 and, as such, relates to driving devices for sewing machines.- More particularly, the invention relates to a drive which may .be converted quickly and conveniently to accommodate alternative sources :of. power.

Both foot treadles and electric motor-s'are well known as sources of sewing machine power and itis known in the art'to convert sewing machines from one source of power to another. Such known conversions require, however, the use of tools, the exchange of parts, belts or the like, and require at least several: minutes of time for each conversion.

Where the conversion is to 'be a permanent one, the -need for tools, parts and a' few minutes of timepre'sents no problem at all. However; there are areas in'par'ts of the world in which electric power is available only sporadically, areas where damageto attehuated power'lines is frequent, or where electric-power is available only while a local factory or mill is operating. In these areas, the sewing machine 'userfas contrasted with a sewing niachine dealer, would have to make the conversion from electric to foot power in order to continue sewing. Moreover, the conversion may be required quite frequently so that the requirement of time, tools and exchange parts becomes onerous.

While the apparatus of the present invention has essentially the same capability as the apparatus of US. Patent No. 3,224,398, i.e., ready selectability between motor and treadle operation, its principle feature is that it obtains such capability in a very simple way, whereby manufacturing expense and ultimate high price to the consumer are obviated. Generally, the invention provides a sewing machine handwheel assembly having two coaxial pulley members for accommodating motor-driven and treadledriven belts respectively. The treadle-driven pulley is directly secured to the sewing machine arm shaft, while the motor-driven belt is coupled to the arm shaft through a spirfal spring that interconnects the pulleys. The motordriven belt is usually kept continually on its pulley; and the treadle-driven belt, though usually off its pulley, may if desired, be slipped easily on its pulley when electric power is unavailable or not applied to the electric motor. When power is applied to the electric motor, the motordriven pulley is directly driven and, through the tightening of the windings of the spiral spring, couples to rotate the other pulley, and so too the arm shaft. With the electric motor disabled, however. the treadle-driven belt may he slipped on its pulley to drive directly the arm shaft. When termined wayr v a The bracket arm shaft'16 is rotatably supported a little electric motor drive to foot treadle drive in a matter of A a few seconds without the use of tools or' exchange parts. Another object of the invention is to provide a sewing machine handwheel assembly that employs a spiral spring to interconnect two pulleys thereof, one pulley being adapted to be motor-driven and the other being adapted to be treadle-driven.

The invention will be described with reference to the figures, wherein,

.FIG. 1 is an elevational view, partly in section, illustrating apparatus embodying the invention.

- FIG. 2 is a view illustrating in detail the assembly of a handwheel according to the invention, and

FIG. 3 is an exploded View of, and useful in describing, the handwheel of the invention.

Referring to the figures, a sewing machine bracket arm 10 is supported by a standard 12 above a work-supporting bed 14. The bracket arm 10 and standard 12, as is conventional, are hollow and contain mechanisms for driving thebracket arm shaft 16. As is known, the bracket arm shaft 16 is adapted to be unidirectionally driven, i.e., in order for the sewing machine to sew, all of the sewing instrumentalities must cooperate in a known and predein from its end in a bushing 18 serving as a journal bearing, and such bushing is fixedly housed within a flange 20 forming part of the bracket arm 10. Holes 22, 24 in the fiange20 serve to permit easy lubrication of the bearing surfaces between the bushing 18 and the bracket arm shaft .16. A bushing 26 is fixedly secured to the end of the bracket arm shaft by means of a set screw 28; and the bushing 26 is so disposed on the shaft 16 that a screwreceiving open end 30 thereof extends beyond the end of the shaft 16. The bushing 26 is provided with a shoulder 32 against which an abutment plate 34 may rest.

The sewing machine handwheel assembly, otherwise called a balance wheel assembly, comprises three main parts: a first pulley member 36, a second pulley member 38, and a spiral spring 40. The pulley member 36 has a central aperture 41 and is provided with a hub 45. Similarly, the pulley member 38 is provided with a hub 46 that extends from an annular recess 48. The hub 46 is provided with a central aperture 50, and is so adapted to slide onto the hub that the end 52 of the hub 46 abuts against the shoulder 54 formed by the hub levels 42, 44. The outer diameter 56 of the hub 46 is so sized that it provides a continuous annular radial level with the level 42. The spiral spring 40 in its preferred form is tightly wound of metal having a generally rectangular cross-section, being coaxially disposed to surround both'the hub 46 and the part 42 of the hub 45. The pulley member 38 is provided with a peripheral annular groove 60 for accepting a motor-driven belt 62, and the pulley 36 is provided with an annular groove 64 for accepting a treadle-driven belt 66.

The annular recess 48 is adapted to accept the forward face 68 of the pulley member 36; and the pulley member 36 may be locked to the bracket arm shaft 16 for rotation therewith by means of an adjustment screw 70 accommodated by the threaded end 30 of the bushing 26. The screw 70 has a knurled head 72, which head is adapted to reside within the concavity 74 of the pulley member 36. With the screw head 72 tightly held abutting against a lock washer 80, the pulley member 36 gets locked to the bracket arm shaft 16. By loosening the screw 70. the

shaft 16 may be completely disengaged from the handwheel assembly, as is often necessary during, say, bobbin winding. The pulley belt 62 is driven by an electric motor 90 that is supported by a bracket assembly 92, such motor 90 being provided with a pulley wheel 94 secured to its shaft 96; and the motor is excitable by means of electric leads 98.

The spiral spring 40 that interconnects the hubs 45 and 46 is so wound that rotation in a given direction of the pulley member 38 by means of the electric motor 90 causes the spring 40 to tighten on each of the hubs 45, 46. This causes the pulley member 36 to follow rotationally the pulley member 38, and since the pulley member 36 is secured to the bracket arm shaft 16 (assuming of course that the screw 70 is tightened down within the bushing 26) then so too the bracket arm shaft 16 gets driven by the motor 90.

On interruption of electrical power to the leads 98 of the motor 90, and with the treadle belt 66 on its pulley member 36, the bracket arm shaft 16 may again be rotated by directly turning the pulley member 36 in the same direction as the above-noted given direction by treadle or foot power. This causes the spring 40 to loosen its grip on the hubs 45, 46, and as such the pulley member 38 and the motor shaft 96 do not get driven when the pulley member 36 is treadle-driven. This assures the long life of the motor by preventing wear of the motor parts, viz. brushes, bearings, etc., when the motor is not in actual use.

While the invention has been described in its preferred form, it is to be understood that the words which have been used are words of description rather than of limitation, and that changes within the purview of the appended claims may be made without departing from the true scope and spirit of the invention.

Having thus set forth the nature of this invention, what is claimed herein is:

1. In a sewing machine, a unidirectional arm shaft an electric motor having an output shaft, a handwheel assembly comprising first and second substantially coaxially disposed driving means, one of said driving means being provided with a hub, said first driving means being a A V pulley adapted to be secured directly to said arm shaft, a treadle belt adapted to be selectively placed on said pulley for directly driving said arm shaft in a given direction, a spiral spring coaxially supported on said hub and interconnecting said first and second driving means, the turns of said spiral spring being always in the same direction from one end of said spring to the other end of said spring, said spiral spring being so wound that rotation of said first driving means in said given direction tends to loosen said spring on said hub and rotation of said second driving means in that same given direction tends to tighten said spring on said hub, and normally engaged means interconnecting said second driving means with said motor shaft for driving said second driving means in said given direction, whereby when said treadle belt drives said first means in said given direction, said arm shaft also gets driven in that given direction but said motor output shaft does not get so driven, and whereby when said motor by means of said normally engaged means drives said second driving means in said given direction, said arm shaft and said first driving means also get driven in that given direction.

2. The apparatus of claim 1 wherein said second driving means is a pulley, and wherein said means interconnecting said motor shaft and said second driving means is a pulley belt.

3. The apparatus of claim 1, wherein each of said driving means is provided with a hub, and wherein said spiral spring is substantially tightly wound about both said hubs.

References Cited UNITED STATES PATENTS 1,055,905 3/1913 Hansen 19241 1,792,818 2/1931 Chason 112217.4 2,742,126 4/1956 Morton 192--41 2,836,276 5/1958 Schwab et al 112219 3,292,453 12/1966 Recknagel 74--625 FRED C. MATTERN, 111., Primary Examiner.

W. S. RATLIFF, Assistant Examiner.

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