US3683439A

US3683439A - Heel support for a shoe lasting machine

Info

Publication number: US3683439A
Application number: US140794A
Authority: US
Inventors: Anton Muhlbach; Rudi Fichtner
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-05-06
Filing date: 1971-05-06
Publication date: 1972-08-15
Anticipated expiration: 1989-08-15

Abstract

A shoe lasting machine having toe wipers and a heel support movable by a fluid pressure motor toewardly into engagement with the heel of a shoe, fluid being fed to the motor through a chamber having a piston at one end, the piston being moved in the chamber a predetermined amount upon engagement of the wipers with the shoe to impart an additional toeward movement of the support.

Description

United States Patent Muhlbach et al.

[54] HEEL SUPPORT FOR A SHOE LASTING MACHINE [72] Inventors: Anton Muhlbach, Montabaurer Str. 44, 623 Frankfurt am Main; Rudi Fichtner, Untergasse 14, 6307 Ober, both of Germany 22 Filed: May6, 1971 211 Appl.N0.: 140,794

[52] US. Cl. ..l2/l4.4 [51] Int. Cl. ..A43d 21/00 [58] Field of Search ..12/8.l, 8.2, 10.5, 12.4, 12.5,

. 12/ 14.4 [56] References Cited UNITED STATES PATENTS 3,464,073 9/1969 Boddy ..12/l4.4 3,477,073 11/1969 Andrews etal ...12/l4.4'

[ 51 Aug. 15, 1972 Primary ExaminerPatrick D. Lawson Attorney-Richard A. Wise, Richard B. Megley and Vincent A. White 1 5 ABSTRACT A shoe lasting machine having toe wipers and a heel support movable by a fluid pressure motor toewardly into engagement with the heel of a shoe, fluid being fed to the motor through a chamber having a piston at one end, the piston being moved in the chamber a predetennined amount upon engagement of the wipers with the shoe to impart an additional toeward movement of the support.

4 Claims, 1 Drawing Figure K I K2 V7 V2 MP Mvl V/ WI Q2 Li W HEEL SUPPORT FOR A SHOE LASTING MACHINE BACKGROUND OF THE INVENTION This invention relates to a movable heel support for holding a shoe against heelward thrust exerted by toe lasting wipers. It is common to provide shoe lasting machines with such heel supports which are moved into engagement with the heel end of a shoe by mechanical as well as fluid pressuremotors. It is essential for optimum shoemaking conditions in the toe lasting of shoes that the shoe not be permitted to move heelwardly. To this end, it is common to lock the support against movement before the heelward thrust is exerted by the toe engaging wipers. This has been accomplished in the past by mechanical pawl and ratchet devices as well as by blocking fluid in the fluid operated motor. Despite these precautions, it frequently occurs that the support is moved heelward by flexing of various parts of the mechanism, resulting in improper lasting of the toe end of the shoe.

Accordingly it is a general object of the invention to overcome this problem in a relatively simple manner. To this end, the heel support is moved into initial engagement with the shoe in the usual manner. When the toe wipers engage the shoe and apply a heelward thrust, an additional toeward movement is imparted to the support to compensate for any heelward movement of the support caused by the thrust of the wipers. According to one feature, the extent of the additional movement of the support is adjustable to compensate for varying shoemaking conditions.

The drawing shows a schematic arrangement embodying the invention in a toe lasting machine and in the following description only elements of a typical mechanism sufficient for general understanding of the invention are described. It should be understood that various substitutions could be made without departing from the scope of the invention as defined by the appended claims.

The drawing shows a shoe 1 held at its heel end by a heel support 2, the toe of the shoe being held against a known type of locating means (not shown) but, for example, which may be a toe band. The heel support 2 usually exerts only a light pressure on the shoe so that no undesirable impressions are made either at the heel or the toe. The heel support 2 is mounted on the end of an hydraulically activated piston 3 that slides in a cylinder 4. Cylinder 4 has an inlet 5 to which pressure fluid is delivered through a feed line 6. Cylinder 4 may be rigidly connected to a wiper head 8, for example, through an arm 7. For clamping the shoe 1 in the machine, it is inserted in the machine and the heel support is moved forward from a retracted position into engagement with the heel end of the shoe by pressure fluid admitted to the cylinder 4.

The wiper head 8 (shown only in essentials) is provided with wipers 9 and 10 which can be moved in a way already known by means of a cross piece 11 and links 1 12 and 1 13 whereby the wipers move heelwardly and inwardly for a wiping in operation. The advance and retraction of cross piece 11 and therewith the wipers is effected by means of a pneumatic device 12 having a push rod 13 connected to the cross piece. On the push rod 13 is attached a cam 14 arranged to activate a switch 15. Cam 14 is adjustably mounted on the push rod 13 and is fixed thereon by a screw 16 so that the activation of switch 15 can be made to depend upon any-selected advance movement of cam 14 and thus of the lasting wipers 9 and 10. For the further description of the design example shown, it is assumed that the cam 14 is so adjusted on push rod 13 that the switch 15 is activated when the wipers pass just over the edge of shoe 1. Activation of switch 15 serves to close its contact a-l and opens its contact a-2 to provide a control signal when the pressure of wipers 9 and 10 upon the shoe upper margin begins. This signal is used to cause the heel support 2 to execute an additional stroke of definite length toward the toe end of the shoe.

At the start of the machine operation, the heel support 2 is in a retracted position with the piston 3 completely withdrawn into the cylinder 4. In this phase, contacts K1 land K2 of an electrical control circuit are open, and the cam 14 has not yet advanced up to the switch 15 since the wipers are still retracted. The contacts K1 and K2 are activate simultaneously, for example by a foot switch. When the contacts K1 and K2 are open, a valve V is in its position V1 and a valve W is in its position W2. In these positions conduits 17 and 18 are connected to exhaust ports T. The same applies to conduit 6 which is connected with conduit 17 through a chamber 30 of an hydraulic activation device 19. Upon closing of contacts K1 and K2, the valve V shifts to its position V2 as a result of the energizing of a solenoid Mvl, and the valve W shifts to its position W3 by energizing of solenoid Mw3. At this time, the contact a-2 is still closed since switch 15 is not yet activated. In the position W3 of valve W, pressure fluid is fed from a line pressure conduit D through a pipe 20 to a reducing valve 21 and a non-return valve 22. The pipe 18 remains connected to the exhaust port T. In this way, pressure fluid at reduced pressure reaches pipe 17 through the valve V in its V2 position, and passes through

ports

28 and 29 in the chamber 30 to pipe 6 to advance the piston 3 until the heel support 2 engages the shoe as shown.

The lasting wipers 9 and 10 then advance by pressurizing the pneumatic device 12. The push rod 13 also advances until the cam 14 engages and actuates the switch 15 when the wipers just begin to press upon the lasting margin of shoe 1. By the activation of switch 15, the contacts a-l and a-2 are reversed, by which they assume their position as illustrated. The solenoid Mw3 is de-energized, and the solenoid Mwl is energized so that valve W assumes the W1 position as shown. With the valve W into its W1 position, pressure fluid is supplied from the line conduit D, through pipe 18 to the lower end of the hydraulic activation device 19.

The device 19 contains a piston 23 which up to this time is held by a spring 24 in the lower end of chamber 30 but when pressure fluid is fed through pipe 18 and an inlet 27, the piston 23 is moved up until it engages an adjusting screw 26. Movement of piston 23 displaces a quantity of pressure fluid from the chamber 30 corresponding to the content of a pressure chamber 25 formed under the piston. The pressure fluid displaced by piston 23 from chamber 30 is blocked from outlet through the port 28 of device 19 by the nonqeturn valve 22 so must pass through the port 29 and the pipe 6 to cylinder 4 via the inlet 5. Thus, the piston 3 and the heel support 2 are moved toewardly a definite distance determined by the stroke of the piston 23. Consequently, the only pressure remaining in the lead 6 is that built up in cylinder 4 in front of the piston 3 as a result of the thrust of the wiper components 9 and 10. In this way the shoe 1 is virtually free from subjection to any additional pressure load. During the continued advance of the wipers 9 and 10, the switch 15 remains activated as a result of the design of the cam 14. The contacts a-l and a-2 are thereby held in their position as shown, whereby the position reached by heel support 2 likewise remains held.

At the end of the lasting operation the lasting wipers 9 and 10 are retracted in the usual manner, de-activating switch so the contact a-l opens and the contact a-2 closes. At this time, the contacts K1 and K2 are opened so that the device as presented returns to its rest position as initially described. In this rest position, the piston 23 is again returned to the end of chamber 30 of the hydraulic device 19 under the effect of spring 24. The pressure fluid in pressure chamber 25 can flow back via the lead 18 since in the rest position the valve W has assumed its W2 position in which the lead 18 is connected to the exhaust port T.

It should be understood that the cam 14 can be adjusted in a variety of positions so that the switch 15 is activated when the lasting wipers have assumed a selected position. The adjustment of cam 14, thus, depends upon the phases of the working cycle of the machine that have been decided upon to suit particular shoemaking conditions. For the same reason, the extent of the additional movement of the heel support can also be varied by adjusting the stop screw 26 which limits movement of the piston 23.

Having thus described our invention what we claim as novel and desire to secure by Letters Patent of the United States is:

1. In a shoe lasting machine having wipers engagable with the toe end of a shoe, and a heel support engagable with the heel end of the shoe; the improvement comprising fluid pressure means for moving the heel support toewardly of the shoe from a remote position into engagement with the heel end of the shoe, and means actuated upon engagement of the wipers with the toe end of the shoe for causing the fluid pressure means to impart an additional predetermined toeward movement to the heel support.

2. A machine according to claim 1 in which the heel support is moved by a fluid actuated motor to which pressure fluid is fed through a chamber, and piston is provided in the chamber, said piston occupying one end of the chamber while the support is moved toewardly into engagement with the shoe, said piston being moved a predetermined distance in the chamber upon engagement of the wipers to displace fluid from the chamber into said motor to impart said additional toeward movement of the heel support.

3. A machine according to claim 2 in which the predetermined movement of said piston is adjustable to vary the extent of said additional heel support movement.

4. A machine according to claim 1 in which the actuated means is adjustable to vary the time of the additional movement of the heel support according to a varied position of the wipers with respect to the toe end of the shoe.

Q22 3 UNITED STATES PATENT OFFICE CERTIFICATE OF=CORECTION t nt No. 3,6 3, 39 Dated Au uw 1?, J9??? I Inventor(s) Anton Muhl baCh and Rudi Fi chtner It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Title page, please insert; Assignee; USM Corporation Signed and sealed this 9th day of January 1973.

(SEAL) Attest:

EDWARD M FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents