US2857996A - Electric clutch-brake driving devices - Google Patents

Description

Oct. 28, 1958 E. P. TURNER ETAL 2,857,996

ELECTRIC CLUTCH-BRAKE DRIVING DEVICES Filed Jan. s, 1956 2 Sheets-Sheet 1 //vv/vr0/?s Edgar P. Turner and Lorenz A. Wendel WITNESS TOR/VEX Oct. 28, 1958 E. P. TURNER ETAL 5 ELECTRIC CLUTCH-BRAKE DRIVING DEVICES Filed Jan. 3, 1956 2 Sheets-Sheet 2 u, """IIIIIII //v VENTORS Edgar R Turner and Lorenz A. Wendel B) IZTOR/VEY ELECTRIC CLUTCH-BRAKE DRIVING DEVICES Edgar P. Turner, Watchung, and Lorenz A. Wendel,

Somerville, N. .L, assignors to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application January 3, 1956, Serial No. 557,045

Claims. (Cl. 192-18) This invention relates to electric power driving devices for operating sewing machines or the "like and more particularly to means for supporting the driving device on the structure carrying the machine to be driven.

The driving devices to which the present invention relates are known in the art as electric power transmitters and generally comprise a housing or casing containing an electric driving motor, a clutch-brake mechanism and having exterior of the housing a driving pulley operatively connected to the driving unit and a depending actuating lever for selectively actuating or braking the driving pulley. The power transmitter is normally mounted on the underside of a table top supporting the.

machine to be driven with the driving pulley of the transmitter in belt driving alignment with the driven machine pulley.

It is an object of the present invention to provide a power transmitter supporting structure which is simple in construction and economical to produce.

It is a further object to provide a novel supporting structure which permits adjustment of the belt tension between the driving and driven pulleys.

In connection with the adjustment of the belt tension, the transmitter is relocated away from or toward the support carrying the driven machine and under some circumstances the actuating lever may be inconveniently positioned relatively to the pedal actuating linkage associated therewith, and may result in improper transmitter operation.

It is accordingly a further object to provide a means for maintaining the desired actuating lever and pedal actuating position independently of the desired belt tensioning position of the transmitter.

Briefly, the objects of the present invention are accomplished by mounting the power transmitter on a supporting bracket constructed to permit movement about a pivot toward and away from the table top carrying the driven machine, thereby to obtain the desired belt tensioning relationship between the transmitter and driven pulley and also by providing an enclosing shroud for the transmitter which is secured thereto in a manner to permit relative axial turning of the transmitter frame whereby the actuating lever appended to the transmitter may be selectively positioned.

In the drawings, Fig. 1 is a front elevational view of a power transmitter attached to a table top by the supporting structure of the present invention.

Fig. 2 is a sectional view of the power transmitter and the support taken along the lines 2-2 of Fig. 1.

Fig. 3 is a sectional view of the power transmitter and support taken along the lines 3-3 of Fig. 1 with the details of the interior of the transmitter omitted and showing alternative belt tightening positions of the transmitter.

Referring more specifically to the drawings the electric power transmitter is shown having a casing 11 comprising a cylindrical frame 12 enclosed at one end by a a cap member 13. Extending from the other end and enclosing the same is an end enclosure bell 14 of a motor 15. Radially projecting from the exterior of the motor frame are a plurality of longitudinal cooling ribs 16 which form a portion of the cylindrical frame 12. For a more detailed description of the transmitter assembly reference may be had to the copending application of Ross D. Ingalls, Serial No. 285,441, filed on May 1, 1952, now Patent No. 2,739,251.

Disposed within the casing 11 adjacent the end cap 13 is the clutch-brake mechanism arranged and constructed in a manner similar to that shown in the above.

mentioned application. Axially projecting from a central aperture provided in the end cap 13 is a pulley shaft 19' having fixedly secured thereto a grooved pulley 20 adapted to receive a continuous belt 21 to drive a sewing machine (not shown) mounted on the table top 22.

The clutch-brake mechanism is controlled by an L- shaped actuating lever 23 which is pivotally supported on a pin 24 carried by a pair of spaced bosses 25 formed on the end cap 13. A yoke 26 is provided on one end of the lever and carries a control pin 27 which extends through a sliding collar 28 having attached thereto, within the housing, a movable clutch member (not shown) which is selectively engageable with either a driven flywheel or a brake to control rotational movement of the driving pulley 20 as explained in the aforementioned copending application.

The other end of the actuating lever 23 has an outwardly projecting L-shaped bracket 29 having attached thereto a pivot member 30 substantially parallel with the lever 23. The pivot member 30 terminates in a ball 31 which seats within the spherical opening 32 provided on one end of a pedal-actuated link which at its other end is adjustably connected by a clamp 34 to a link 35 which is connected to a foot treadle 36.

By the present invention the transmitter casing is provided with a novel enclosing shroud 37 which is constructed and mounted on the frame 11 of the transmitter in a manner to permit limited axial turning of the transmitter about its longitudinal axis and also to provide for attaching the power transmitter 10 on a supporting bracket 46 for bodily arcuate movement about a pivot toward and away from the table top.

As shown, the shroud 37 is a split-cylinder made of sheet metal and has overlapping portions. The upper overlapping portion is formed with a tongue 38 which extends between spaced projecting clamping; lugs 39 fixedly secured to the shroud by welding or the like. Also secured to the shroud by welding are spaced straps 40 terminating in upstanding clamping lugs. 41 adjacent the edge of the upper overlapping portion of the shroud 10 and in alignment with the lugs 39.

The shroud 37 is slidably fitted over the cylindrical frame 11 and engages the outer periphery of the radial ribs 16. The frame is held in a fixed position within the shroud by tightening the screws 42 passing through openings 43 in each of the lugs 39 and the respective aligned threaded openings 44 in the lugs 41 to draw the lugs 39 and 40 together against the action of spring 45 disposed around the screw between the lugs until the shroud is clamped against the cylindrical frame 11 including the ribs 16 of themoto-r 15.

The power transmitter is mounted on the underside of a table top 22 by a supporting bracket 46 secured to the table top by bolts 47 and nuts 48. The bracket comprises a mounting plate 49 formed with a flat horizontal portion 50, adapted to rest flush against the underside of the table top, and a depending inclined portion 51.

The plate is also formed with downwardly depending side are provided adjacent the lower edge. 7 of the inclined portion 51,

Patented Oct. as, 1958- ings'53 in which a horizontal hollow supporting tube 54-issecured preferably with a force fit.

In a transmitter support, it is frequently necessary to adjust the belt tightness on the driving pulley in order to maintain the desired driving relationship with the sewing machine pulley and it is desirable that this be accomplished with the minimum amount of elfort and inconvenience. By the present invention this is accomplished byattaching the transmitter to the supporting bracket 46 for pivotal movement about the supporting tube 54, whereby the transmitter including the driving pulley 20 is swingable in an arc toward and away from the table top 22. As shown, each of thestraps 40 secured to the shroud 38 extend tangentially therefrom and is formed with a curved end portion 55 adapted to partially encircle the tube '54. Associated with each strap 40 is a clamping plate 56 secured thereto by a stud 57, each strap adjacent its free end being formed with a curved portion 58 substantially complemental to the curved portion 55 of the strap 40 to form therewith a tube engaging clamp. In order to maintain the straps 40 tangential with the shroud there are provided braces 59 which are fixedly secured at one end to the strap 40 and the other end to the shroud 37 by welding or the like.

To assure that the transmitter 10 maintains'its desired angular position about the supporting rod 54 a novel adjustable link connection is provided between the bracket and thetransrnitter. As shown, this link connection-comprises a split sheet-metal band 60 which encircles the shroud between the straps 40. One end of the band is formed with a pair of spaced ears 61 which carry a pin 62 having a central opening through which a screw 63 passes. Spaced from the edge of the other end of the band and fixedly secured thereto is a projecting lug 64 having a threaded opening adapted to receive the screw 63. Encircling the screw 63 between the lug 64 and pin 62 is a compression spring 65. In order to maintain the band fixed on the transmitter it is apparent that it is only necessary to tighten the screw 63 and thereby draw the band tight against the outer surface of the shroud 37 which has previously been clamped on the cylindrical frame 11.

Pivotally connected to the pin 62 is one end of curved H.-shaped link 66 which at its other end is pivotally mounted on a stud 67 secured in a substantially -U- shaped bracket 68, the latter being secured adjacent the free edge of the horizontal portion of the bracket by a rivet or the like.

From the foregoing description it is apparent that the tightening of the belt on the driving pulley with the mounting structure of the present invention has many advantages.

In .the event it is desired to change the tightness or tension of the belt the transmitter is moved toward or away from the driven machine support 22 as shown in Fig. 3, wherein the dotted and full lines show two alternative positions of the transmitter. To obtain the desired belt adjustment, the band 60 encircling the transmitter is unclarnped by loosening the screw 63 whereupon the compression 65 spring functions to open the band. With the band 60 opened the band and the transmitter may be rotated relatively to each other and the transmitter may be swung up or down, about the supporting tube 54 within the limits of the length of the link 66 until the desired belttension is obtained. During the relative turning of the band and transmitter, and the swinging of the latter about the tube54, the pivot pin 62 on the band 60,:carrying one end of the, link 66 swings arcuately with thetransmitter and also :moves circularly with the band 60 about the transmitter toward or away from the fixed pivot stud .67 c'arryingthe other end of the link 66. Since the link 66 is of fixed length, when the band 60 is tightened and clamped on the shroud 38 of the transmitter which is located in its new belt tightening position, the

When the belt tension is adjusted in the above manner,

that is by swinging the transmitter about the tube 54, the lever moves out of the substantial vertical plane shown in Fig. 2. Under some circumstances this may be undesirable since the relocation may, for instance, cause interferencewithother mechanisms mounted on the .underside of the table or may cause the treadle actuating links 34 and 35 to bind, resulting in improper transmitter .operation. By the present invention the shroud 38 is split as above described and When the screws 42 are loosened the springs 45 between the lugs 39 and 40 tend to enlarge the shroud .thereby to permit limited turning of the transmitter frame including the actuating lever until the latter is again in the substantially vertical plane. It is, of course, to be understood that in order to enlarge the opening of the shroud 37 to permit turning of the transmitter frame the band will also be opened. Thereafter the shroud is tightened against the transmitter frame and the *band 60 is clamped on the shroud 37 as described above.

Having thus set .forth the nature of the invention, what we claim herein is:

1. 'The combination of a power driving unit having an actuating lever and mean-s for adjustably mounting thedriving unit on the structure carrying the machine to be driven; said driving unit having a substantially cylindrical casing including a longitudinal axis; a split band adapted to encircle slidably said casing and having a pivot member fixedly secured thereto, said band having means for clamping said band on said casing to secure said band on said casing selectively to position angularly said pivot member relatively to said driving unit axis; said mounting means including pivot means parallel with said driving unit axis; means connecting said unit to said pivotal mounting means for swinging said driving unit about said mounting pivot means towards and away from the machine to be driven; and a link pivotally mounted at one end to said mounting means and at its other end to said band pivot member to position angularly said driving unit relatively to said mounting pivot means when said band pivot member is selectively positioned.

,2. The-combination of a power driving unit having an actuating lever and means for adjustably mounting the driving unit on the structure carrying the machine to be driven; said driving unit comprising a substantially cylindrical frame having a longitudinal axis and including an encircling shroud clamped on said frame; a split band adapted to encircle slidably said shroud, said band having a pivot member fixedly secured thereto and means for clamping said band on said shroud selectively to position said band pivot member on said encircling shroud; said mounting means including pivot means parallel with said driving unit axis; means connecting said unit to said pivotal mounting means for swinging the driving unit aboutsaid mounting pivot means towards and away from the machine to be driven; and a link pivotally mounted at one end to said mounting means and at its other end to said band pivot member whereby said driving unit is angularly positioned relative to said mounting pivot means when said band pivot is selectively positioned.

3. The combination of a power driving unit having an actuatinglever and a supporting bracket for adjustably mounting the driving unit on the support structure carrying the machine to be driven; said driving unit comprising a substantially cylindrical frame having a longitudinal axis; a splitshroud adapted to encircle slidably said frame whereby said frame may be turned about its longitudinal axis in said shroud; means for constricting said shroud to clamp said frame therein thereby to maintain said actuating lever in a selective plane; said supporting bracket including driving unit pivot means substantially parallel with said frame axis and means including adjustable means operatively connected to said shroud and said bracket for maintaining said driving unit angularly positioned on said bracket pivot means.

4. The combination of a power driving unit having an actuating lever and a supporting bracket for adjustably mounting the driving unit on the support structure carrying the machine to be driven; said driving unit being mounted for movement toward and away from the support structure and comprising a substantially cylindrical frame, a split enclosing shroud slidably encircling said frame whereby said frame may be turned about its longitudinal axis in said shroud, means for constricting said shroud to clamp said frame therein thereby to maintain said actuating lever in a selective plane, said supporting bracket having driving unit pivot means substantially parallel with the frame axis, driving unit mounting means swingably supported on said driving unit pivot means and connected to said shroud, link pivot means operatively connected to said shroud and adjustably turnable about said frame axis, and a link pivotally connected at one end to said bracket and at its other end to said link pivot means for maintaining said driving unit angularly positioned on said driving unit pivot means.

5. The combination of a power driving unit having an actuating lever and a supporting bracket for adustably mounting the driving unit on the support structure carrying the machine to be driven; said driving unit comprising a substantially cylindrical frame including a longitudinal axis; a split enclosing shroud adapted to encircle 6 slidably said frame whereby said frame may be turned in said shroud; means for constricting said shroud to clamp said power unit therein thereby to maintain said actuating lever in a selective plane; said supporting bracket having driving unit pivot means substantially parallel with said frame axis; driving unit mounting means swingably supported on said driving unit pivot means and connected to said shroud; a split band adapted to encircle slidably said shroud, said band having a link pivot means fixedly secured thereto; means for clamping said band on said shroud to position angularly said link pivot means relative to said frame axis; and a link pivotally connected at one end to said adjustable link pivot means and at its other end to said bracket for maintaining said driving unit angularly positioned on said driving unit pivot means when said pivot band member is selectively positioned.

References Cited in the file of this patent UNITED STATES PATENTS 1,282,198 Davis Oct. 22, 1918 2,680,504 Schweda June 8, 1954 2,702,106 Strahota et al Feb. 15, 1955 2,703,369 Voigt Mar. 1, 1955 FOREIGN PATENTS 75,148 Denmark Dec. 15, 1952

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