US2529442A - Knee operated shifting device - Google Patents

Description

Nov. 7, 1950 w. A. ANDRES 2,529,442

KNEE OPERATED SHIFTING DEVICE Filed Aug. 4, 1949 3 Sheets-Sheet 1 Jnverzfaz William ZZ. Undres- Wifnau 15g fwfi%% W affozneg Nov. 7, .1950 w. A. ANDRES 2,529,442

KNEE OPERATED SHIF TING DEVICE Filed Aug. 4, 1949 3 Sheets-Sheet 2 nullllHHIlld 71427212 fax William ZZ. Umzres QYzfnezw @ffozweg Patented Nov. 7, 1950 UNITED STATES PATENT OFFICE.

Application August 4, 1949, Serial No. 108,537

8 Claims.

This invention relates to improvements in knee-shift devices for at will actuating presserfoot lifting mechanisms, trimmers, thread cutters, etc. More particularly, this invention relates to improvements in knee-shift devices of the type disclosed in my prior U. S. Patent No. 2,067,038, January 5, 1937,- for operating presserfoot lifting'mechanisms of sewing machines.

While it is known in the art to provide lifting mechanism whereby the presser-foot may be raised by a knee or foot operated device, the point at which the operating force must be applied and the direction of the force that must be delivered from the knee-shift device to the presser lifting mechanism differs considerably in the various types of sewing machines. I-Ieretofore, many varieties of knee-shifting devices have been used, each having application to a limited number of types of sewing machines.

One of the objects of this invention, therefore, is to provide an improved knee-shift device having a structure that will permit greater latitude of adjustment than may be had with any prior device of this type. This object encompasses the provision of a universal knee-shift device which will be adaptable to a large variety of sewing machines as well as to the individual requirements of different sewing machine operators.

A further object of this invention is to provide an improved knee-shift device which may be adjusted to deliver an actuating force in any of a wide range of directions, thereby still further increasing its adaptability. More particularly, my invention aims at providing a device adapted to deliver, interchangeably, either an upward push or a downward pull.

With these and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts hereinafter described in connection with the accompanying drawings, which illustrate a preferred embodiment of the invention and in which:

Fig. l is a front elevational view of a sewing machine having associated therewith a preferred form of my improved knee-shift device adapted to operate one type of presser-foot lifting mechanism;

Fig. 2 is an enlarged side view, partly in section, of the knee-shift device of Fig. 1;

Fig. 3 is a sectional view taken substantially along line 33 of Fig.2, showing in full lines the position of parts as they occur in Fig. 1, and

showing in dotted lines the alternate arrangement of parts as illustrated in Fig. 4;

Fig. 4 is a rear end elevational view of a sewing machine, showing the knee-shift device arranged to operate a presser lifting mechanism of a type differing from that illustrated in Fig. i; and

Fig. 5 is a perspective view of the knee lifter supporting bracket.

While the knee shifter of this invention is not restricted in its application to any particular type of sewing machine, a preferred application, as shown in Figs. 1 and l, illustrates its use With a machine of the conventional type having a bed [0 from which rises a hollow frame including a vertical standard II which supports an overhanging arm l2 formed at its free end with a sewing head l3. The bed It of the machine is adapted to register with and enter a cutout portion of a Work table [4 upon which the machine is supported.

The knee-shift device is shown in the drawings in two alternative positions of adjustment in order to illustrate its adaptability to two different types of presser-foot lifting mechanisms, one requiring an upward pushing force to elevate the presser-foot and the other requiring a downward pull.

In Fig. 1, the presser-foot lifting mechanism illustrated is of the usual type which requires an upward push as an actuating force. Slidably journaled in the head 13 is a vertically. disposed presser-bar [5 that is spring biased downwardly as atl 6 and carries at its lower extremity a presser-foot H. The lifting mechanism comprises a rock shaft i8 journaled in bearing lugs l8.ll within the hollow overhanging arm l2 and having at one end a rock arm 20 which is connected with the presserbar l5 by the pivoted link 2i. At its other extremity, the rock shaft 18 is provided with a second rock arm 22 which is engaged by a push rod 23 that extends downwardly to a point below the base of the machine, where the rod 23 is adapted to receive an upward pushing movement from a separate actuating device such as my improved knee shifter.

In Fig. 4, the knee-shift device is shown as applied to a sewing machine equipped with a presser-foot lifting mechanism of the type disclosed in the U. S. patent of J. D. Karle, No. 2,332,087, dated October 19, 1943, in which a downward pull is required to raise the presserfoot. With this type of lifting mechanism, a cable 24 is used to transmit movements from the knee shifter to the presser-bar. The cable is directed from the presser-bar (not shown), over pulleys 25 on the overhanging arm |2 to a kneeshift connecting element 26 which extends downwardly to a point beneath the base of the machine and is there provided with a tongue 21 attached to the knee-shift device.

My improved knee-shift device comprises a unitary structure supported by an angle bracket 28, the base 29 of which is provided with slotted fastening-screw apertures 39 which permit the knee-shift device to be secured for limited adjustment to the under side of the sewing machine table l4. Depending vertically from the base 29 is 'an arm 3| which is formed with a horizontally extending boss 32 having an elongated socket 33, the outer extremity of the boss 32 being split at 34 and formed with opposing ears 35-35, one of which is drilled and the other tapped to receive a clamping screw 36 in the usual manner.

An elongated shaft bearing member 31, having a longitudinal bore 38, is formed with a reduced cylindrical portion 31' which is adapted to enter the socket 33 of the supporting bracket in telescopic fashion, the clamping screw 36 serving to lock the bearing member selectively in the socket 33 to any desired extension or angular position. A web 39 is provided between the depending bracket-arm 3| and the boss 32 to lend added stability to the bearing member 31.

J ournaled for turning movement in the longitudinal bore 38 of the bearing member 31 is a shaft 40 which carries pinions 4|, 42, one at each extremity, the pinions being secured to the shaft by means of set screws 43-43.

Turning movements may be imparted to the shaft 49, at the will of the sewing machine operator, by means of a pivotally supported gear segment 44 which is adapted to mesh with the pinion 4|. The gear segment 44 has an apertured hub 45 which is pivotally hung upon a stationary stub shaft 46 that is supported at one end in an aperture 41 in the depending bracket-arm 3| and secured at its other end in an apertured lug 48 which depends from the base 29 of the supporting bracket. Preferably formed integral with the gear segment 44, at a point below the hub 45, is a block 59, apertured to adjustably receive the horizontal arm of a lever rod that is secured in the block 59 by means of the set screw 52. A knee pad 53 is adapted to be selectively positioned along the vertical arm of the lever rod 5|. It will be apparent that the lever rod 5| may be inserted from either side of the apertured block 59, thus providing a wide range of possible positioning of the knee pad by which to satisfy the individual requirements of different sewing machine operators. 7

The gear segment 44 is formed with a stop lug 54 which is adapted to strike the base 29 of the bracket 28 so as to limit the turning movements of the gear segment in the direction of the normal at rest position. A coil spring 55 encircles the stub shaft 46 and is adapted to angularly bias the gear segment to the extreme position determined by the stop lug 54. I

By means of the pinion 42, the turning movements of the shaft 49 effect actuation of a rack 56 which is formed along one side of a rod 51. The pinion 42 is disposed in a housing recess 58 formed in the extremity of the bearing member 31. The rack 56 is slidably journaled in, position to mesh with the pinion 42 by means of the bore 59 that is formed in the extremity of the bearing member transversely of the longitudinal bore 38 4 and joining tangentially with the pinion housing recess 58.

In order to adapt the rod 51 to deliver either a push or a pull to the presser lifting mechanism of the sewing machine, each extremity of the rod is specially formed. A fiat surface 69 is formed at one extremity transversely of the axis of the rod, thereby adapting the rod for use with those presser lifting mechanisms requiring an upward push to operate, as shown in Fig. 1. The other extremity of the rod 51 is provided with a tongue 9|, apertured at 62, for attachment to the tongue 2'| of a presser lifting mechanism requiring a downward pull as illustrated in Fig. 4.

A collar 63 is adapted to be secured on the rod 51 to act as a stop member in selectively limiting the extent of motion of the knee-shift device. The collar 63 may be adjustably secured to the rod at either side of the bearing member 31. When positioned as shown in Fig. 2, the collar 63 may be adjusted along the rod to act in place of the stop lug 54 on the gear segment 44, if for instance, any other than the fixed position afforded by the stop lug 54 is desired. By, positioning the collar 63 on the opposite extremity of the rod 5?, as illustrated in dotted lines of Fig. 4, movement of the device in the extreme operative direction may be selectively controlled so that the strain exerted by the operator, should she actuate the device too forcefully, will be assumed by the knee-shift device rather than by the more delicate presser-foot lifting mechanism of the machine.

As illustrated in Figs. 1 and 4, the knee-shift device is adapted to be secured to the under side of the machine supporting table M such that the shaft 49 extends toward the rear of the machine in a direction generally parallel to the line of stitch formation. The slotted fastening screw apertures 39 permit the device to be bodily shifted for a limited amount in a direction laterally of the sewing machine.

The above described knee-shift structure provides for ready adjustment of the position of the rod 51 into alignment with either a push rod 23 (Fig. 1) or a cable connecting element 26 (Fig. 4)

so as to properly deliver the necessary actuating movements to the presser lifting mechanism. To facilitate this alignment, positioning movements of the rod 57 toward or away from the operator 1 in the direction of the line of feed may be accomplished by loosening both the clamping screw 36 of the boss 32 and the set screw 43 of either of the pinions 4|, 42, whichever is most convenient. With the clamping screw 36 loosened the position of the bearing member 31 may be adjusted lengthwise of the socket 33, and since the rod 5'! is slidably journaled in the bearing member 31, this adjustment permits selective positioning of the rod. 7

In the drawings, Fig. 2 illustrates the position of parts when the bearing member 31 is clamped in a position of minimum extension from the socket 33. In Fig. 4, the device is shown with the bearing member 37 clamped in approximately maximum extended position. After lengthwise of movement of the rack 56. The full line portion of the drawing shows the bearing member 31 and rod 51 in position to deliver an upward push. As shown in the dotted line portion of Fig. 3, the bearing member has been rotated through an angle of 180 from the full line position so that the rack 56 meshes with the pinion 42 on the opposite side of its axis of rotation and therefore will be moved in a direction opposite the movement which will occur in the mechanism as illustrated in the full line position. This angular adjustment of parts will also place the tongued extremity 6! of the rod 51 uppermost, whereby the rod will be properly positioned to deliver a downward pulling force to the presser lifting mechanism.

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

1. A unitary device for operating a sewing machine presser-foot lifting mechanism, comprising a supporting bracket having a socket formed therein; a bearing member adapted to be supported in said socket; a shaft journaled in said bearing member; mechanism for manually imparting turning movements to said shaft including, a pinion secured to one extremity of the shaft, a gear segment pivotally carried by said bracket in mesh with said pinion, a knee-shift lever attached to the gear segment; and mechanism operatively associated with said shaft and constructed and arranged to impart translatory movements to the presser lifting'mechanism from the turning movements of the shaft.

2. A unitary device for operating a presser-foot lifter mechanism of a table-supported sewing machine, said device comprising a supporting structure adapted to be secured to the under side of thetable-top, a shaft carried by the supporting structure in substantially parallel relationship with said table-top, a pinion secured to said shaft, a rack meshing with said pinion and adapted to operatively engage the presser-foot lifter mechanism, and a manuall operable connection for imparting turning movements to said shaft.

3. A knee-shift device for operating a sewing machine presser-foot lifting mechanism, comprising, a supporting bracket, an elongated bearing member adapted to be adjustably secured in said bracket for selective positioning therein, a

associated with said shaft for deriving translatory movements suitable for operating a presser-foot lifting mechanism from the turning movements of the shaft, said means being carried by said bearing member so as to partake of the selectiv adjustment thereof.

4. A knee-shift device for operating a sewing machine presser-foot lifter comprising a supporting bracket having a socket formed therein, an elongated tubular bearing member adapted to enter said socket for lengthwise adjustment relative thereto, clamping means associated with said socket for securing the bearing member in set position, a shaft journaled in said bearing member, a rack slidably journaled in said bearing member and extending transversely of said shaft,

a pinion carried by said shaft in mesh with said rack, and manually operable means carried by said bracket for imparting turning movements to said shaft.

5. A knee-shift device for operating a sewing machine presser-foot lifter comprising a supporting bracket having a socket formed therein, a cylindrical tubular bearing member supported for angular adjustment within said socket, clamping means associated with said socket for securing the bearing member in set position, a shaft journaled in said bearing member, a rack slidably journaled in said bearing member and extending transversely of said shaft, a pinion carried by said shaft in mesh with said rack, and manually operable means carried by said bracket for imparting turning movements to said shaft.

6. A knee-shift device for operating a sewing machine presser-foot lifter comprising a supporting bracket having a socket formed therein, an elongated bearing member adapted to enter said socket for lengthwise adjustment, said bearing member being formed to provide for selective angular positioning in said socket, clamping means associated with said socket for securing the bearing member in the desired position, a shaft journaled in said bearing member, a rack slidably journaled in said bearing member and extending transversely of said shaft, apinion carried by said shaft in mesh with said rack, and manually operable means carried by said bracket for imparting turning movements to said shaft.

'7. A knee-shift device for operating a sewing machine presser-foot lifter comprising a support ing bracket having depending arm, a boss carried by said arm and having a socket formed therein; a bearing member formed with a longitudinal bore and a transverse slot, and. adapted to enter said socket for selective lengthwise and angular positioning therein; bearing member clamping means associated with said boss; a shaft rotatably journaled in said longitudinal bore, a pinion carried by the shaft; a rack slidably journaled in said transverse slot and meshing with said pinion; and means for imparting turning movements to the shaft, including a second pinion carried by said shaft; a gear segment pivotally supported on said bracket and meshing with said second pinion, and a manually actuated lever carried by said gear segment.

8. A manually actuated knee-shift device for operating the presser-foot lifting mechanism of a sewing machine, comprising a supporting bracket having a socket formed therein, a bearing member adjustabl disposed in said socket and having a pair of transversely arranged bores, clamp means for securing said bearing member in a selected one of a plurality of positions in said supporting bracket, a shaft journaled in one of said bores, knee operated connections for turning said shaft in said bearing member, a presser-foot lifting mechanism engaging rod journaled in the other of the bores in said bearing member, and operative connections between said shaft and said rod for endwise displacing said rod during turning of said shaft.

WILLIAM AUGUST ANDRES.

No references cited.

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