US2745123A

US2745123A - Shoe press pad

Info

Publication number: US2745123A
Application number: US375087A
Authority: US
Inventors: Maxwell C Suerken
Original assignee: LAMAC PROCESS Co
Current assignee: LAMAC PROCESS Co
Priority date: 1953-08-19
Filing date: 1953-08-19
Publication date: 1956-05-15
Anticipated expiration: 1973-05-15

Description

Jinan May 15, 1956 Filed Aug. 19, 1953 M. C- SUERKEN SHOBPRESS PAD 2 Sheets-Sheet l INVENTOR.

MVMCM y 15, 1956 c. SUERKEN 2,745,123

SHOE PRESS PAD Filed ug. 9. 1953 2 Sheets-Sheet 2 QQODOOOGOOO 52 FIG. 7

WCSW

United States Patent SHOE PRESS PAD Maxwell C. Suerken, Erie, Pa., assignor to Lamac Process Company, Erie, Pa., a corporation of Delaware Application August 19, 1953, Serial No. 375,087

Claims. (Cl. 12-38) In shoe sole cementing machines, it may be desirable that the unit pressure be higher at the shank than at the heel and toe so that the force dissipated in conforming the shank of the sole will not result in inadequate cementing pressure. This invention is intendedv to achieve this result in machines using inflatable pressure pads. Use is made of an auxiliary'pad resting on the casing of the inflatable pad under the shank of the sole and having substantially greater area than the shank. Lateral stiffening rods embedded in the auxiliary pad permit flexing in a longitudinal direction or lengthwise of the shank, but make the pad essentially rigid in a direction crosswise of the shank. This results in a total force on the shank of the sole proportional to the area of the auxiliary pad rather than to the area of the shank and accordingly increases the unit pressure at the shank so that the pressure is adequate both to conform the shank of the sole and to provide the desired cementing pressure.

In the accompanying drawings, Fig. 1 is a side elevation partly in section of a shoe cementing press in the closed position; Fig. 2 is a top plan View of the shoe press pad; Fig. 3 is a section on line '3-3 of Fig. 1 with the shoe shown in dotted lines; Fig. 4 is a section on line 44 of Fig. l with the shoe shown in dotted lines; Fig. 5 is a section on line 5-5 of Fig. 4 with the shoe .shown in dotted lines; Fig. 6 is a top plan view of the auxiliary pad underlying the shank portion" of the sole; Fig. 7 is anend view of the auxiliary pad; and Fig. 8 is a diagram of the unit pressure exerted on the heel, shank, and toe sections of the sole being cemented.

The invention is shown applied to a press of the construction disclosed in Patent 2,654,104, granted October 6, 1953. As there disclosed in greater detail, the press unit is mounted on a frame 1 and comprises a lower frame 2 having its base 3 suitably fixed to the top 4 of the frame 1 and a pressure arm 5 pivoted at 6 on the lower frame 2. The pressure arm 5 is biased to the raised position by a tension spring 6:: attached to a bell crank lever 7 pivoted at 8 on the lower frame 2. The bell crank lever has an arm 9 pivoted to a link 10 carried by a depending arm 11 on the pressure arm. The links 9 and 10 serve as a toggle lever for moving the pressure arrn between open and closed positions. In the closed position, the arm 9 strikes an adjustable stop 12, which is adjusted so the common pivot 13 of the toggle lever is slightly above the center line of toggle linkage. When the press is open, as shown in dotted lines, the pressure arm 5 is raised and heel and

toe pressure members

14 and 15 are sufliciently above a pressure pad 16 to permit convenient insertion and removal of a shoe 17 on a last 18 and having a sole 19 which is to be cemented. This gives the operator space to load and unload. Each of the heel and toe pressure members is carried at the lower end of an adjusting screw 20 adjustable both lengthwise and up and down of the pressure arm 5.

The pressure pad 16 is carried in a box-shaped base 21 having side and

end walls

22 and 23 surrounding the edges of the pad. Within the base is fixed a sole plate 24 2,745,123 Patented May 125,, 1956 "ice and a pivoted heel and shank plate 25, which is adjustable by means of a screw 26 to accommodate different types of shoes; The base 21 is suitably secured to the base 3 of the frame 2.

As shown in greater detail in Figs. 3 and 4,. the pressure pad comprises an envelope or casing 27 usually of leather with an inflatable bladder 28.

The press is closed by a foot pedal 29 pivoted at 30 on the frame 1. The cementing pressure is developed by air pressure supplied through

lines

48, 46 leading to valve stem 47 on the rubber bladder 28, the pad pressure is released by venting the pressure through lines 45, 46 and the press is opened by the spring 6a after the pad pressure is released.

As far as the present invention is concerned, other shoe cementing presses may be used. The pressure exerted on the sole comes from inflating pressure in the bladder of the shoe press pad rather than from the construction of the press. I

When the bladder 28 is inflated, the air pressure exerts a uniform pressure over the entire inner surface of the bladder. Although this pressure is likewise transmitted essentially uniformly to the pad casing 27, some of the force is dissipated in making the sole 19 conform to the shoe so that the effective cementing pressure actually transmitted is not uniform throughout the area of the sole. It is accordingly desirable that a higher unit pressure be exerted at the shank area 49 of the sole than at the heel 50 or toe 51. The shank 49 is the part of the sole which undergoes the greatest deformation in conforming to the shoe, particularly in the type of shoe illustrated where the sole must, in addition, conform to the breast 52 of the heel; higher pressures in the shank section of the sole were desirable in order to obtain the uniform cementing.

obtained by the auxiliary pad 53 shown in Figs. 6 and 7,

which is mounted on the shoe pad casing 27 under the shank 49 of the sole. The pad has a body of, a suitable elastomer such as natural orsyntheti'c rubber or plastic having a wedge-shaped upper surface with an 'inclined section 54 under the shank of the shoe and an inclined section 55 under the breast of the heel. It is expected that the user will buff the

surfaces

54 and 55 so as to fit any particular style of shoe. The pad 53 is essentially rectangular in shape and has a width substantially greater than the width of the shank 49 of the sole. A plurality of lateral stiffening rods 56 are embedded into the pad. Because these stiffening rods 56 extend crosswise of the pad, the pad is free to flex lengthwise along the shank 49 of the sole, but is essentially rigid in a direction crosswise of the shank of the sole. From one aspect the surface of the pad underlying the shank of the sole behaves as though it were made of rigid strips or lamina extending crosswise of the pad and covered with elastic or flexible material conforming to the shank. The operation would be the same if the auxiliary pad were built into and formed part of the pad casing or a flexible cover for the complete top surface of the pad casing. In fact, the auxiliary pad acts as though it were part of the top surface of the pad casing. Two of the rods 57 extend out each side of the auxiliary pad 53 and are hooked into suitable eyelets 58 in a leather strap 59, which underlies the shoe press pad and has its free ends extending up along the side of the pad opposite the shank portion 49 of the sole. The auxiliary pad 53 will work in the same manner, whether anchored in place by the strap 59, or whether merely resting loosely on the upper surface of the pad casing 27. The strap 59 is merely a convenient way of holding the auxiliary pad in the proper location so that the operator will not be disturbed by having to relocate the auxiliary pad in case it accidentally becomes It has long been recognized that displaced from the correct position. By this construction, he total force transmitted to the auxiliary pad 53 from the casing 27 of the inflated pad 16 is substantially equal to the unit pressure exerted by the bladder 28 times the area of the auxiliary pad 53. Since the auxiliary pad 53 is essentially rigid in a crosswise direction, the force exerted on the shank 49 is directly transmitted to the shank 49 and as shown in Fig. 8, the unit pressure exerted on the shank 49 is substantially greater than the unit pressure exerted on the heel 50, or toe 51. This is precisely What is required for adequate cementing.

If the stiffening rods 56 were omitted, the auxiliary pad 53 would merely be buried deeper into the casing 27 and the unit pressure exerted on the shank would not be substantially increased. The stiffening rods 56 are necessary in order that the pressure exerted on the shank may be proportional to the length of the rods rather than to the unit pressure within the bladder. With this construction, the unit pressure exerted on the shank 49 of the sole is increased by a factor equal to the ratio of the length of the rods 56 to the Width of the shank portion of the sole underlying the rods. While the shank 49 of the sole is flexed considerably in a direction lengthwise of the shoe, in a crosswise direction the shank is essentially flat or possibly slightly curved. The curvature is slight enough so that the resilience of the elastomer, which comprises the body of the auxiliary pad 53, is sufficient to conform to the shank of the sole.

Cementing presses are used for forming or sole-laying, even though the sole is not cemented to the shoe and the higher unit pressure on the shank of the sole is advantageous in this use.

What is claimed as new is:

1. In a shoe press, a pad having an inflatable casing for pressing a sole against a shoe, the casing having a surface underlying the sole and being substantially wider than the sole at the shank of the sole, an auxiliary pad substantially wider than the shank of the sole forming part of said surface of the casing beneath the shank, said auxiliary pad being flexible in a direction lengthwise of the shank and rigid in a direction crosswise of the shank whereby the unit pressure exerted on the shank of the sole is higher than over the remainder of the sole.

2, In a shoe press, a pad having an inflatable casing for pressing a sole against a shoe, the casing having a surface underlying the sole and being substantially wider than the sole at the shank of the sole, an auxiliary pad substantially wider than the shank of the sole forming part of said surface of the casing beneath the shank, said auxiliary pad having a body of flexible material with longitudinally spaced reinforcing rods therein extending crosswise of the shank.

3. In a shoe press, a pad having an inflatable casing for pressing a sole against a shoe, the casing having a surface underlying the sole and being substantially wider than the sole at the shank of the sole, an auxiliary pad having a body of an elastomer substantially wider than the shank of the sole forming part of said surface of the casing beneath the shank, and means restraining flexing of the body in a direction crosswise of the shank but not lengthwise of the shank whereby the unit pressure exerted on the shank of the sole is higher than over the remainder of the sole.

4. The construction of claim 3 in which the restraining means comprises rods embedded in the body extending crosswise of the shank and spaced apart along the length of the shank.

5. In a shoe press, a pad having an inflatable casing for pressing a sole against a shoe, the casing having a flexible top surface underlying the sole and being substantially wider than the sole at the shank of the sole, and the portion of the surface engaging the shank of the sole comprising elastic material overlying rigid lamina extending crosswise of the shank and spaced apart lengthwise of the shank whereby the portion of the surface engaging the shank of the sole is flexible in a direction lengthwise of the shank and rigid in a direction crosswise of the shank whereby the unit pressure exerted on the shank of the sole is higher than over the remainder of the sole.

References Cited in the fileof this patent UNITED STATES PATENTS 388,377 Smith Aug. 21, 1888 1,160,983 Hemanover Nov. 16, 1915 1,910,858 Ruhr May 23, 1933 1,953,224 Hazleton Apr. 3, 1934 2,187,828 Finn Jan. 23, 1940 2,255,155 Farnum Sept. 9, 1941 2,497,195 Woodman et a1. Feb. 14, 1950