US2501810A

US2501810A - Shoe jack

Info

Publication number: US2501810A
Application number: US54100A
Authority: US
Inventors: Checchia John
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-10-12
Filing date: 1948-10-12
Publication date: 1950-03-28
Anticipated expiration: 1967-03-28

Description

March Z8, 1950 l, CHEQCHIA Zil@ SHOE JACK Filed Oct. 12, 1948 IN V EN TOR.

John hecdla BY HHH Patented Mar. 28, 1950 UNITED STATES PATENT VOFFICCE- SHOE JACK J ohn Checchia, Cheltenham, Pa.

Application October 12, 1948, Serial No. 54,100

7 Claims.

My invention relates to a new and useful shoe vjack such as used by shoemakers and shoe repairers to support the lasts on which shoes are placed while parts, such as soles, half soles, heels and the like, are being attached, as by nailing, to another structural part of the shoe, such as the upper, for example.

An object of the invention is to provide a simple and effective means to hold the rotary head in any adjusted position, said means being so constructed that it will not be harmfully effected by hammer blows imparted to the head and to provide a last releasing means in said head thereby eliminating the necessity of striking the last for rel-easing the same which often results in a broken or damaged last.

Another object of this invention is to provide a mechanism for holding the jack head in any adjusted rotary position, the actual holding elements being arranged radially to the vertical shaft carried by said head, said mechanism being released by pressure applied through an operators foot and constantly urged towards a locking position.

Another object of the present invention is to provide means for holding the jack head in any preselected rotary position, said means consisting of a gear fixed to a vertical shaft carried by the head for rotation with the latter and a plunger having one or more teeth to mesh with gear teeth and hold said gear and associated parts against rotation, said plunger, when released by pressure applied to a pedal, being retracted by a spring and subsequently returned to the holding position by another spring actuated plunger when the pressure on the pedal is relieved.

Another object of the invention is to construct the housing for the plungers and pedal as an integral part of the base of the shoe jack.

With the above and other objects in view this invention consists of the details of construction and combination of elements hereinafter set forth and then designated by the claims.

In order that those skilled in the art to which this invention appertains may understand how to make and use the same I will describe a construction in detail referring by numerals to the accompanying drawing forming a part hereof, in which- Fig. 1 is a side view of a shoe jack constructed in accordance with my invention.

Fig. 2 is an enlarged vertical section of the lower part of the jack, portions of the base being broken away.

Fig. 3 is a sectional elevation on the line 3-3 of Fig. 2.

In carrying out my invention as herein embodied I0 represents the base of the shoe jack having a threaded socket I I in the Ytop thereof to receive the tubular supporting standard I2 which has its lower end threaded to be screwed into the socket. Preferably said base has a recess I3 in the bottom thereof or is hollow underneath, as shown in Fig. 2. This will provide a relatively thin wall I4 betw-een the bottom of the socket I I and the recess I3 for a purpose to be presently referred to.

A housing I5 is formed as an integral part of the base I0 and projects upwardly therefrom to one side of the socket II to permit assembly of the tubular standard I2 and situate said housing contiguous said standard when the latter is in place. A horizontal transverse hole I6 runs completely through the housing from the concave inner surface thereof, which coincides with the outer surface of the tubular standard, to the OPPO- site or outer front surface of said housing and the outer end of said hole I6 is normally closed by a screw plug II. The inner end of the hole I6 is of reduced size to provide a shoulder I 8 adjacent said inner end.

A holding plunger is slidably mounted in the horizontal hole I6 andincludes a head I9 having an inclined extremity preferably provided by forming the outer end of head cone shaped. From the inner end of said head I9 extends a neck 20 which, undercertain conditions, projects out of the inner end of the horizontal hole I6 and through a hole 2I in the tubularstandard I2 which hole 2I aligns with the hole I6. The terminal end of the neck 20 has one or more vertical teeth 22, Fig. 6, formed `thereon to mesh with the teeth of a spur gear 23 fastened on a vertical shaft 24 depending from the head 25 of the shoe jack. The vertical shaft is located in the longitudinal center of the tubular standard and is projected through a hole 26 in the wall forming the bottom of the socket II. The wall acts as a bearing for the lower end of said vertical shaft which is held against accidental withdrawal by a fastening device 21, such as a cotter pin, and a washer 28 may be disposed between said fastening device and the adjacent wall of the base.

The holding plunger is normally urged towards a retracted position by a spring 29 surrounding the neck 20 and engaging the head I9 as the movable element and the shoulderA I8 as the stationary element. Said holding plunger` is prevented from rotatingby forming the inner end of the horizontal hole IB and at least a portion of the neck 20 of corresponding rectangular shapes or by providing a key and keyway in the proper associated parts. The holding plunger being non-rotatable insures a positive meshing of the toothed end of said holding plunger with th-e gear.

The housing I also has a vertical hole 30 running inwardly from the top of said housing, intersecting the horizontal hole I6 and terminating an appreciable distance below said hole I6 but short of the bottom of said housing or the actual base I0. In the upper end or portion of the vertical hole 30 is slidably mounted a pedal 3l including a. shank 32 having a sliding llt in said vertical hole with a portion projecting outside and carrying a head 33 to be engaged by an operators foot for actuating the pedal. The reciprocating movements of the pedal are limited by a stop screw 34 threaded through the upper part of the housing at the front thereof and projecting into the vertical hole 30 and a slot 35 in the pedal shank, said slot running longitudinally of said shank and providing shoulders for coaction with the stop screw. A thin finger or push rod 36 of reduced diameter relative to the shank projects inwardly from the inner end of said shank in the axial center thereof.

The terminal end of the finger 36 engages the flattened apex of the conical head 3l of the control plunger and said head 3l slidably coacts with the conical head I9 of the holding plunger to move the latter outwardly or permit its retraction. The control plunger is slidably mounted in the lower part of the vertical hole 30 and is urged upwardly or outwardly by a spring 38 seated in the bottom of said hole 30 and, preferably, projecting into a oavity'39 formed in the inner end of the bod3r of said control plunger. The spring 38 is stronger than the spring 29 in order to overcome the strength of said spring 29 andany friction between the associated operating parts.

In practice, with the work on the last and said last in the jack head, said work may be readily rotated into any desired position by ldepressing the pedal 3| which will push the control'plunger inward against the action of its spring 38. This will permit the holding plunger to retract under the influence of` its spring 29 to withdraw the toothed end of the neck 20 from the gear thus releasing said gear so that it and the vertical shaft and the head of the jack can be freely rotated. When the desired position is obtained, pressure is relieved from the pedal 3I' and the spring 38 will move the control plunger outward thereby projecting the holding plunger outwardly towards the gear until the toothed end of the neck 20 again meshes with the teeth of said gear to prevent rotation of said gear and associated parts which, in effect, looks the parts in the adjusted position or holds the work in the selected location. It is to be particularly noted that while the jack head rests on the standard I2, blows struck on the last, and more particularly on the work supported by the last, are transferred through the head to the vertical shaft. Since any jarring lengthwise of said shaft and the gear teeth are parallel to the axis of the shaft no damaging impacts will be transferred to the holding mechanism.

Of course I do not wish to be limited to the exact details of construction herein shown and described as these may be varied within the scope of the appended claims without departing from the spirit of my invention.

of the standard, a holding plunger slidably mounted in said housing and having a toothedv end projecting from the housing and through a hole in the side of the standard, a gear fixed to the vertical shaft within said standard to be engaged by the toothed end of the holding plunger for temporarily holding the gear and associated parts against rotation, means to urge said holding plunger towards a retracted position, and means to force the holding plunger into and normally retain it in the holding position.

2. The shoe jack structure according to claim l, wherein the means for controlling the holding plunger includes a control plunger slidably mounted in a vertical hole in the housing and intersecting the horizontal hole, both plungers having coacting tapered heads, a spring to urge the control plunger towards the holding plunger, said spring being stronger than the holding plunger spring, and a pedal to move the control plunger against the action of its spring and out of the path of travel of the holding plunger,

3. In a shoe jack, a base having a recess in its underneath portion and a threaded socket in the top thereof with a hole forming a communication between said recess and socket and located in the center of the latter, a tubular standard removably mounted in the socket, a jack head rotatably mounted on top of said standard, a vertical shaft depending from the jack head and projected through the hole in the base, means on the projected end of said shaft to temporarily hold it in place, a gear secured to said shaft and located within the tubular standard, a housing supported by the base, and mechanism in said housing and having a portion projecting from the housing and through a hole in the standard for cooperation with the gear to temporarily hold it and associated parts against rotation for retaining the jack head in any predetermined position.

4. In a shoe jack, a base having a recess in the bottom and a threaded socket in the top thereof with a hole forming a communication between said recess and socket and located in the center of the latter, a tubular standard removably mounted in the socket, a jack head mounted on top of said standard and rotatable about the vertical axis of the standard, a vertical shaft secured to the bottom of the jack head and depending therefrom in the axis of the standard with the lower end of said shaft projecting through the hole in the base to extend into the recess. means on the lower end of said vertical shaft within the recess and coacting with the underneath face of the base to hold said shaft in place and permit it to rotate with the jack head, a spur gear mounted on said vertical shaft within the tubular casing, a housing formed as an integral part of the base and projecting upwardly with one face contiguous the standard when the latter is assembled on the base, a holding and a control plunger slidably mounted in suitable holes at right angles to each other, each plunger having a conical head, the heads normally coacting with each other whereby the holding plunger is forced outwardly or permitted to retract according to the position of the control plunger, a spring to urge the holding plunger towards a retracted position, said holding plunger projectable lthrough a hole in the standard and having teeth to mesh with the gear, a second spring stronger than the first mentioned one to urge the control plunger in a direction across the retracting path of travel of the holding plunger, and means mounted in the housing to be pressed for forcing the control plunger against the action of its spring to permit the holding plunger to be retracted by its spring.

5. The structure according to claim 4 wherein the means to actuate the control plunger in opposition to its spring comprises a pedal slidably mounted in the housing in endwise alignment with said control plunger and including a pedal shank having a longitudinal slot, a thin push rod depending from said shank to engage the apex of the control plunger head, and stop means mounted in the housing and projected into the shank slot.

6. In combination, a base carrying a tubular upright standard on the upper end of which is rotatably mounted a head having a. depending vertical shaft projecting into said standard in the axial center thereof with a spur gear attached to said shaft and having the serrated perimeter in line with a hole through a side of said standard, a housing on said base extending upwardly along side of the tubular standard and provided with an inner curved surface coinciding with the exterior of said standard, said housing having a transverse horizontal hole therethrough of two diameters, the portion of smaller diameter being located at the inner side of the housing and aligning with the hole in the side of the standard and further provided with a vertical hole extending part way into the housing from the upper end thereof and intersecting the horizontal hole with a bottom below said horizontal hole, means to close the outer end of said horizontal hole, a holding plunger slidably mounted in the hori zontal hole and comprising a head having a tapered terminal end and a reduced neck with a. toothed terminal end for projection through the smaller portion of the horizontal hole and the hole in the side of the stan-dard for coaction with the gear, a shoulder formed by the difference in the diameters of the two sections of the horizontal hole, a spring about the reduced neck of the holding plunger and engaging the head of said holding plunger and the shoulder to urge said holding plunger towards a retracted position, a control plunger slidably mounted in the lower part of the vertical hole and including a head having a tapered terminal end for coaction with the tapered end of the holding plunger to move the latter forward and permit its retraction when said control plunger moves forwardly and is retracted respectively, another spring stronger than the first mentioned one and located between the control plunger and the bottom of the hole in which said control plunger is mounted to urge said control plunger forwardly, a pedal to retract the control plunger, said pedal comprising a shank slidably mounted in the upper part of the vertical hole and extending outside of said vertical hole and a reduced linger depending from the inner end of said shank and engaging the control plunger and a head on the outer end of the shank, said shank having a longitudinal slot providing shoulders at both ends thereof, and a stop screw projected through the housing into the vertical hole and said slot for coaction with the shoulders at the ends of the slot to limit the movements of the pedal and consequently theV movements of both plungers.

'7. The structure according to claim 6 wherein the housing is formed as an integral part of the base and the control plunger has a cham-ber in its inner end to receive a portion of the spring which actuates said control plunger in one drection.

JOHN CHECCHIA.

No references cited.