US2975443A - Last jacks - Google Patents

Description

March 21, 1961 s. A. MAKOVSKI LAST JACKS Filed March 12, 1959 Inventor Stephen A. fl/fa/mw/vi iinited States Patent- 2,975,443 LAST JACKS Stephen Akroyd Makovski, Leicester, England, assignor to United Shoe Machinery Corporation, Flemington, N.J., a corporation of New Jersey This invention relates to a jack for alastgsuitable for presenting a shoe on a last to a shoe machine and, more particularly, is concerned with improvements in such a jack for facilitating the presentation of a last to and its removal from the jack.

Shoe machines commonly are provided with a jack upon which a last with a shoe thereon is presented to the machine for the performance of an operation upon the shoe. Typically, the jack comprises a jack pin which is received in the usual thimble in the heel part of the last; and the jack pin projects from a seat on the jack which is engaged by the top surface of the heel part to support the last against such pressures as are exerted upon the shoe toward the last bottom during the shoe'making operation.

In the manufacture of lasts of the type disclosed in United States Letters Patent No. 2,806,233, granted September 17, 1957, upon an application of A. R. Hubbard et al., much attention is given to their accuracy and to locating the thimble in a definite position longitudinally of the last as well as perpendicular to the top of the heel part. Moreover, with a view to realizing the advantages of the accuracy of such a last, the jack pin of the machine is fitted as closely as possible to the thimble of the last to effect as accurate a positioning of the last upon the jack and with respect to the machine as is possible. With lessened clearance between the thimble and jack pin, presentation of the last to the jack has become more difficult, whether the last is assembled upon the jack by an operator or by apparatus especially designed for this purpose. a

In view of the foregoing, it is a general object of the invention to facilitate the presentation of a last to a jack in respect to the mounting of the last upon the jack pin, as well asthe accurate positioning of the last on the jack so that it will be presented to the machine in exactly thedesired relation thereto.

Pursuant to this objective, the invention makes provision, in accordance with one feature thereof, for a jack having a post within which a jack pin is fully retractable whereby the last may be readily placed on the jack with the topoffits heel part seateduponthe post, the jack being further, character'med by the provision of a socket on the post for receiving the rim of the top of the heel in register with the jack pin, together with means, ac-

tuated'inresponse topresentation ofthe, last to the jack,

entering last whelreby the'last thi mble ispositioned receive apositioning plate on a'last of the type disclosed in the above mentioned Hubbard et al. patent, which plateis tapered lengthwise of the last. More specifically, the above-mentioned "socket is constituted by tapered guiding means on the post which co-operates with the similarly tapered portion of the positioning plate to limit the'movementof presentation of thelast to the jack, when a state of register between the jack pin and thimble is reached, and also to prevent any lateral movement of the last upon the jack.

The invention further contemplates the provision, in accordance with a further feature, of means for holding the top of the heel part of the last against the jack post during the insertion of the jack pin into the thimble whereby axial alinement of the thimble and jack pin is maintained and the last is prevented from being lifted 01f the post by the jack pin.

The foregoing and other features of the invention, including the provision of an auxiliary last locating pin, magnetic means co-operating with the last to hold it on the post and control means for activating the magnetic means when the jack pin and auxiliary pin are inserted into the last, will now be disclosed in further detail in the following specification with reference to the drawlugs, and will be defined in the appended claims.

In the drawings? Fig. 1 is a side elevation of an'illustrative jack embodying the invention; and

Pig. 2 is a plan view of the jack.

The illustrated jack comprises a post 10 having a later-' ally offset head 12, the upper horizontal surface of which constitutes a seat 14 for supporting the upper surface of a positioning plate P on a last L of the type disclosed in the above-mentioned Hubbard et al. patent. The last is provided with the usual thimble T in its heel part and a bore B, the thimble and bore being perpendicular to the top of the plate P.

A jack pin 16 and an auxiliary locating pin 18 are mounted to slide axially thereof, in the head 12, from retracted positions below the seat 14 into the thimble T and bore B of a last on the jack, whereby the last is accurately positioned upon the jack. The pins 16, 18 are mounted upon a bar 20 which is connected by a link 22 to an armature 24 of a solenoid S which is fixed to the post 10. The armature 24 is biased downwardly by a spring 25, whereby the pins are urged toward and are normally held in their retracted positions.

Upon the top of the head 12 there is a fixed guide member 26 having convergent guiding shoulders 28 which bound the sides of a tapered socket which is shaped in conformity to the rearward tapered portion of the plate P. The guide member is so positioned upon the head 12 that when the positioning plate of the last is fully received in the socket, the thimble T and bore B are disposed in axial alinement with the jack pin 16 and auxiliary pin 18, respectively. A stop plate 30 having a chamiered shoulder 32 and fixed upon the forward portionof the seat 14 is arranged to prevent movement of the last, by engagement with the forwardend of the positioning plate, out of the socket forwardly thereof while the last is seated upon the seat.

in order toovercome any tendency of the pins 16 and 18 to lift the last ,ofi the seat "during the insertion of the pins intothe last, there maybe recessed into the head 12 in the area betweenthe shoulders 28 a permanent magnet or, as herein illustrated, an electromagnet '34 which co-operates with the positioning plate, the latter being made of a magnetic metal, to hold thelast downupon the seat. The illustrated magnet'34 is energized under the control of a switch 36, which is fixed upon the rear portion of the guide member 26 andhas a plunger 38 which is operated, to close the switch, by the rear end of the last in response to its presentation to the jack.- As the positioning plate P becomes fully received withinthe socket, asherein illustrated, the. switch 36 is closed and, being electrically connected'in series with the electromagnet 34 and the solenoid S,causes the mag net and solenoid to be energized simultaneously. Thus, the last is held magnetically upon the seat and the jack pin 16 and auxiliary pin 18 are thrust upwardly through the seat 14 and into the last. 3 i A Prior to the removal of the last from the jack, power,

amass o a) is cut off from the solenoid and electromagnet by opening a switch on the post 10, which may be either operator controlled or automatically operated by the machine with which the jack is associated, whereby the last is no'longer held against the seat 14 and the pins 16 and 18, being biased downwardly, are withdrawn from the last into their original positions below the seat 14.

i In presenting a last to the jack, whether it is done by an operator or b y apparatus especially designed for this purpose, the last is preferably moved lengthwise thereof in a substantially horizontal position with its positioning plate P just above or resting upon the plate 30. As the tapered portion of the plate becomes confined between the shoulders 28, the last is positioned and its rearward movement is limited so that the thimble T and bore B are axially alined with the jack pin 16 and auxiliary pin 18. As this relation between the last and the pins is closely approached, the plunger 38 is depressed by the rear end of the last to close the switch 36 whereuponthe magnet 34is energized, causing the last to be held down upon the seat 14 and, simultaneously, the solenoid is operated whereby the jack pin 16 and auxiliary'pin 18 are inserted in the last.

"After the operation to be performed upon the shoe on the last has been completed and the pins 16 and 18 have been retracted out of the last, the latter may be readily removed from the jack in a direction opposite to its movement of presentation to the jack. For various reasons,

'the construction of the illustrated jack facilitates the mounting of a last thereon and the removal of the last therefrom. That is, whether the last is presented to the jack by hand or by apparatus, the judgment of an operator' or the design of the apparatus is not required to obtain a relationship of register between the pins 16, iii and 1 the thimble T and bore B. This relationship between the last and the'illustrated jack is automatically secured by fully'inserting the positioning plate P into the socket of the guiding member 26. Moreover, by holding the top surface of the positioning plate seated upon the seat 14, the thimble T and the bore B are disposed in a coaxial relationship with the sins i6 andlB, whereby any tendency for the pins to jam while being inserted into or withdrawn from the last is avoided. Finally, because the pins 16 and 18 are retracted beneath the seat 14 when the presentation of the last to and its removal from the jack is effected, the pins do not constitute an obstruction to the above-mentioned movements of the last in a most convenient direction, that is, longitudinally of the last.

Having described my invention, what I claim as'new and; desire to protect by Letters Patent of the United States'is: V

L. A last jack comprising a post for supporting the top of the heelpart ofa last a jack pin mounted for move ment axially thereof from an inoperative position within saidipost into anoperative position within the thimble of a last-on the jack, said post having a socket for receiving the rim of the top of'the heel part of the last whereby its thimble is positioned in register with said jack pin, andrneans actuated in response to insertion of the last into said socket. for operating said jack pin be tween its said positions. I g

2:A last jack comprising a post having a seat for supporting the top of the heel part of a last, a jack pin mountedfor movement axially thereof from within said post through said seat into the thimble of a last on the jack, said'post having a socket for receiving the rim of the topof the heel part of the last whereby its thimble is positioned in register with said jack pin, means for operating said-jack pin to cause it to be inserted into the last-,--and control'means operated by the last in response to its presentation tosaid socket for actuating said firstrnentionedmeans. I

3; A jack for a last having a positioning plate fixed uppn the top of its heel ,part', said jack comprising a post adapted to be engaged by the top of said positioning plate, a jack pin mounted for movement in said post from a retracted position within said post into the thimbleof a last on the jack, a socket on said post co-operatmg with the periphery of said plate to locate the last upon" the jack with said jack pin and the last thimble in register with each other, means for operating said jack pin in one direction to cause it to be inserted into the last, and spring means biasing said jack pin .in the opposite direction to return said jack pin to its retracted position.

4. A jack for a last having a tapered positioning plate fixed upon the top of its heel part, said jack comprising a post having a seat adapted to be engaged by the top of said positioning plate, a jack pin slid-ably mounted in said post for movement through said seat into the thimble of a last on the jack, a tapered socket on said post for positioning the last by engagement with said plate, and means for operating said jack pin to insert it intothe last.

5. A jack for a last having a plate which is tapered lengthwise of the last and is fixed upon the top of its heel part, said jack comprising a post, a jack pin mounted for movement in said post from withiri'said post into the thimble of a last on the jack, tapered guiding means on said post arranged to receive said plate upon the presentation of the last tosaid jack lengthwise of the last whereby said thimble is located in register with said jack pin, means associated with said post co-operating with said plate to hold the last against said post, means for operating said jack pin to cause it to be inserted into said thimble, and control means operated by the last in response to its presentation to the jack for actuating said last-mentioned means.

' 6. A jack; for a last the heel part of which is provided with a thimble and an auxiliary positioning recess, saidand auxiliary pin in register with said thimble and auxiliary recess, respectively, and means for operating said jack pin and auxiliary pin to cause them tov be inserted intov the last;

7. A jack for a last an upper portion of the heel part of which is magnetic, said jack comprising a post .in which ajack pin is mounted for movement axially thereof from within the post into the thimble of a last on the jaclga socket on said post for receiving the rim of the top of the heel part of the last whereby its thimble is positioned'in register with said jack pin, magnetic means in said post co-operating with said last to. hold the last seated upon said postwithin said socket, and means for operating, said jack pin to cause it to be inserted into said. thimble.

8. A jack for a last an upper portion of the heel part of which is magnetic, said jack comprising a post having a seat for supporting the top of the heel partof a last on the. jack, a jack pin slidably mounted in said post for movement from beneathsaid seat into the thimble ofthe last, guiding means on said seat for directing the last as it is presented to the jack in a direction extending lengtha with said jack pin, means for operating said jack pin to cause it to be inserted into the thimble of the last, electromagnetic means in said post for holding said last against said seat, and control means operated'by the last in response to its movement of presentation tothe jack for actuating said electromagnetic means and said jack pin operating means. I 1

V 9. A jack for a last carrying upon the'top of its heel par-ta magnetic positioning plate having convergent sides, said jack comprising a post adapted to-be engaged by the top of-said positioning plate, ajack pin" mounted in' said post for movement from within saidipostinto;the thimble of a last on the jack, convergent guides on said post arranged to co-operate with the convergent sides of said actuating said electromagnetic means and said first-menplate to position a last on the jack with the thimble of the tioned means.

last in register with said jack pin, means for operating said References Cited in the e of this patent jack pin to insert it into the last, electromagnetic means in said post for holding the last against said post, and 5 UNITED STATES PATENTS control means operated in response to the movement of 2,242,251 Lancaster May 20, 1941 presentation of the last to the jack for simultaneously

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