US2404989A - Vulcanizer - Google Patents

Description

Jill 30, 1946. P, H D ETAL 2,404,989

VULCANIZER Fild June 25, 1944 5 Sheets-Sheet 1 July 30, 1946. Pa SCHMED ET AL 9 9 VULCANIZER Filed June 25, 1944 :5 Sheets-Sheet 2- July 30, 194 6.

P. SCHMID ETAL 2,404,989

VULCANIZER Filed June 23, 1944 3 Sheets-Sheet 5 10 1s s F2 9 2 Patented July 30, 1946 UNITED STATES PATENT OFFICE VULCANIZER Paul Schmid, Jamaica, and Henry Hylton, Brooklyn, N. Y., assignors to Acme Air Appliance 00., Inc., Brooklyn, N. Y., a corporation of New York Application June 23, 1944, Serial No. 541,710

4 Claims. 1

The present invention appertains to vulcanizers of the type disclosed in Patent No. 2,290,106, granted July 14, 1942, to W. H. Longstreet, which vulcanizers are primarily adapted for use in vulcanizing rubber valve stems to inner tubes of pneumatic tires and the like.

As shown in the prior patent above referred to, vulcanizers of this class usually include a base or frame on which a heater unit, preferably electrically operated, is mounted and against the heating surface of which the inner tube and valve stem are firmly clamped by an adjustable pressure platen to hold the valve stem and inner tube in cooperative relation during the vulcanizing operation. The heater unit and the base or frame of the vulcanizer are respectively provided with aligned openings in which the shank of the valve stem is received in arranging the valve stem in th usual inverted position, with its flanged base resting upon the heating surface at the upper side of the heater unit. This inverted position of the valve stem has been found to be the most convenient for the attachment of the valve stem to the inner tube by vulcanization.

The desirability of confining the heat, as far as possible, to the heating surface of the heater unit and preventing overheating of the shank of the Valve stem have been recognized as being of considerable importance in vulcanizers of this type, and to the attainment of these ends, the vulcanizer of the aforementioned patent was particularly designed to reduce the heat conduction from the heater unit to the base or frame by the reduction of contact between the heater unit and the base or frame by the provision of widely spaced supporting surfaces on the frame, while the frame was so designed as to permit an induced circulation of air upwardly therethrough and about the shank of the valve stem. This arrangement gave rise to certain unforeseen practical difficulties in the manufacture and assembly of the vulcanizers. The present invention has, accordingly, been developed as a material improvement over the prior design so as to eliminate these practical difiiculties, while at the same time preserving and more effectively attaining the ultimate general aims which characterized the former design.

To be more explicit, it is one of the primary objects of the present invention to provide a vulcanizer fram or base having provision for mounting a heater unit thereon so that the heater unit will be supported without imposing undue strains upon either the heater or the frame. This is preferably attained by forming the base or frame with a continuous, circular and level heater supporting surface with which the heater unit, usually of circular form, is in contact all the Way around the heater, the heater unit itself being provided with hold-down bosses of ample size to withstand the clamping strains imposed by the firm attachment of the heater unit to the base or frame by means of a minimum of hold-down screws or equivalent fastening instrumentalities.

Another important object of this invention is to provide an efficient and economical heater unit in which all parts of the heater assembly are completely enclosed within a housing or casing, and which may be sealed to make the heater unit tamper-proof.

Another object of the invention is to provide an improved heater unit assemb1y, all parts of which are readily accessible for purposes of repair or replacement if any part should become defective after long use, thereby minimizing th labor and cost attending such repair, and eliminating the necessity of replacing the entire heater unit.

In order to confine the heat to the vulcanizing surface of the heater unit, which is the top surface thereof, and minimize transfer of heat to the vulcanizer frame or base, an improved, highly efficient arrangement of insulation is employed both within the heaterhousing and between the housing and the frame, thereb insuring, along with the induced circulation of air about the shank of the valve stem during the vulcanizing operation, against overheating of the valve stem.

A still further object of our invention is to provide a novel and improved cooperative relationship between the various elements of the heater unit, including th electrical heating coils, thermostat control and extension cord, whereby to minimize strains on these individual elements and the electrical connections therebetween incident to accidental jerks or strains upon the extension cord.

Other and further objects of the invention will be hereinafter referred to and the novel features thereof defined in the appended claims.

In the drawings:

Figure 1 is a view in side elevation of our improved vulcanizer, illustrating the manner of use thereof in vulcanizing a rubber valve stem to an inner tube, the latter elements being shown in broken lines;

Figure 2 is a view in rear elevation of the vulcanizer;

Figure 3 is an enlarged fragmentary view in top plan of the heater supporting end of the vulcanizer frame or base, particularly illustrating the continuous heater supporting surfaces at the outer margin thereof and about the central opening through the base, which respectively cooperate with the heater unit when mounted thereon, the heater unit being omitted from this View, and certain other parts of the base being shown in section;

Figure 4 is a sectional view taken on the line I i-4 of Figure 3 Figure 5 is an enlarged bottom plan View of the heater unit in its completely assembled form;

Figure 6 is a sectional view taken on the line 66 of Figure 5, and particularly illustrating the details of the heat-control or thermostat unit including its porcelain mounting;

Figure 7 is a sectional view tal-ren on the line l l of Figure 5;

Figure 8 is a view in side elevation of the functional parts of the thermostat or heat-control unit; and

Figure 9 is a sectional View taken on the line S9 of Figure 5.

Like reference characters designate corresponding parts in the several figures of the drawings, wherein 6 generally denotes the base or frame of the vulcanizer, 2 the heater unit, 3 the pressure platen, 4 the pressure screw, and 5 the pressure platen supporting arm which is pivotally connected to the frame at 5. Most of these parts may be formed of simple metal castings, suitably reinforced by lateral ribs to strengthen the same. The base or frame 5 is preferably so constructed that it may be conveniently mounted upon a Work bench, table or other suitable supporting surface, 1

for which purpose a flat pad l' having inwardlyinclined lateral faces 8, S at opposite sides thereof, is provided on the bottom of the frame I at the rear end thereof. This pad. I, which has a more or less dovetailed shape in transverse cross section, is adapted to be slidably received in a bracket of corresponding outline (not shown) which may be fastened to the work table or work bench for releasable cooperation with the pad, as disclosed in the prior Patent No. 2,290,106 hereinbefore referred to.

As shown best in Figures 1 to 4 inclusive, it will be seen that the forward end of the frame I is enlarged and is provided with a central vertical opening extending completely therethrough from top to bottom thereof, as indicated at 8. The portion of the frame around this opening 8 is preferably extended downwardly and terminates at its lower en din a laterally extended circular base 9, the lower face of which lies in the same plane as the lower face of the pad I. This base 9, together with the pad 1', allows the vulcanizer to stand without other support When removed from the bench clamp o bracket in which it is normally supported by engagement with the pad 1, when the vulcanizer is in use.

The upper side of the forward end of the frame i, around the opening 8, is enlarged in the form of an inverted cone, as indicated at It, the upper end of which terminates in a horizontal annular rim l i, which in turn is provided with a relatively low upstanding marginal flange 52 which is adapted to embrace the lower edge of the heater unit 2 when the latter is mounted on the frame i. It will be seen that the upper face of the rim l I is perfectly flat and continuous so that when the heater unit 2 is placed thereon, as shown in Figures 1, 2 and 4, it is effectively Supported all the way around and perfectly balanced, with no undue strains imposed upon either the heater unit or frame at any one point. Contributing to the support of the heater unit and to the minimizing of strains thereon and on the frame, the central part of the frame about the openin 8 is upwardly extended in tubular form as indicated at 3, and the upper end of this extension terminates in the plane of the upper heater-supporting face of the rim i l, for supporting engagement with the central portion of the heater unit, as will be best understood by reference to Figures 3, 4 and 6.

The size of the opening 8 through the frame is proportioned so that it is substantially larger than the size of the valve stem which is illus" trated in broken lines and designated M in the drawings. The purpose of this is to allow cool air to freely enter the lower end of the opening 8 and rise upwardly around the valve stem i i until it reaches the openings H5 in the central extension !3, at which point the air may pass outwardiy through the openings 35 into the space it within the conical enlargement iiof the frame, and thence outwardl through the openings ii and back to the atmosphere. A continuous circulation of relatively cool air about the valve stem is thus attained in the manner of a chimney effect, similar to that described in the patent previously referred to.

Referring now to the heater unit generally designated 2, this unit preferably includes an annular housing or casing of inverted cup-shaped form, the upper side iii of which constitutes the vulcanizing surface. The central portion of this vulcanizing surface i8 is depressed or recessed as indicated at if to fit the base flange of the valve stem 14, which base flange is designated 26. As previously indicated, the heater unit is provided with a central opening 2!, which is aligned with and forms a continuation of the opening 8 in the frame I, and into which openings the valve stem it extends when positioned for vulcanization to the inner tube, the latter being designated 22. The housing or casing of the heater is formed with a central tubular extension depending from the upper side of the housing as indicated at 23, and defining the central opening 2! within the same, the lower end. of this extension terminating on a plane with the lower end of the outer marginal flange 24 depending from the outer margin of the vulcanizing surface 18. The annular space 25 between the flange 24 and central tubular extension 23 is utilized to receive and enclose the heating element and associated functional parts of the heater .unit.

The heating element preferably includes a circular porcelain plate 25 having formed in its upper face a series of grooves 21 for receiving the electrical heating coils 28 which are located at the side of the plate 25 facing the vulcanizing surface E8 of the heater unit, thereby raising the vulcanizing surface to the desired working temperature and minimizing chilling of the vulcanizing surface when cold rubber is placed on the vulcanizing surface. A sheet of mica, or other suitable insulation, designated 29, is preferably interposed between the heating coils 28 and the upper side of the housing of the heater unit to prevent short-circuiting of the heating coils. Boneath the porcelain plate 25 in which the heating coils 23 are arranged, there is provided a layer of insulating material, such as asbestos, designated 36, which prevents the heat from being directed downwardly and contributes to the confining of the heat in the vulcanizing surface. An additional closure plate of metal or other suitable material, designated 3|, may also be provided, if desired, for closing the bottom heater unit beneath the heating element, as clearly shown in Figures 4 to 7 inclusive. This closure plate 3|, the asbestos insulation 30, and the porcelain plate 26 carrying the heating coils 28 are all preferably attached to the heater unit housing by a plurality of screws designated 32, passing through these elements and threaded into the upper side of the housing. Three of these screws, designated 32, have been shown in the drawings, but it is to be understood that the number may be varied as desired.

Also mounted in the housing of the heater unit is a heat-control unit generally designated 33,

the same including a mounting element made of porcelain or other insulating material, designated 34, which serves to support a thermostat unit, designated 35, of any approved type, the details of which are not material to an understanding of this invention. The thermostat element generally illustrated in the drawings is of the bi-metal type, but it is to be understood that any other type of heat-control may be employed where desired. The important object of this feature of the invention is to completely enclose the heat-- control unit within the housing of the heater unit,

while at the same time simplifying the mounting thereof and affording ready access thereto for replacement, repair or adjustment when required. 3

It will be seen particularly from reference to Figures 5 and 6 that the heat-control unit is mounted in one side of the housing of the heater unit and is attached thereto by two screws, des1gnated 36, which are threadedly engaged in bosses :1;

31 formed on the inner face of the outer marginal flange 24 of the heater unit housing. Similar bosses 38 are provided for engaging the screws 32 previously refered to. In mounting the heatcontrol unit in the housing of the heater unit,

an additional layer of insulating material, such as asbestos, is interposed between the porcelain mounting 34 and the closure plate 3i, as indicated at 39. The closure plate 3| and the asbestos insulation 30 are suitably cut away as indicated at 40 to accommodate the heat-control mounting as shown best in Figure 6 of the drawings, this end of the mounting housing the thermostat elements proper and completely enclosing the same to prevent their accidental damage. Suitable connections are established between the heating coils 28 and the heat-contro1 unit, one such connection having the form of a bus bar designated 4|. One side of the heat-control unit is also connected to one wire of an extension cord 42, this connection being made at 43 which designates a terminal provided at one end of the thermostat element. The other wire of the extension cord 42 is connected to a terminal post 44 which is carried by the porcelain mounting 34, and which in turn is connected to the opposite end of the heating coils 28, thus completing the circuit through the thermostat and the heating coils. A third wire, grounded to the heater casing at one of the bolts 32, may be employed when the heater is connected to a 220-volt power line.

As seen best from reference to Figures 5 and 9, the outer marginal flange 24 of the housing of the heater unit is interrupted at 45, and through this interruption, the porcelain mounting 34 is extended outwardly, as shown at 46. This extension 46 is recessed at 41 to fit snugly around the extension cord 42, and a cord clamp bar 48 bridges the recess 41 across the cord 42 and firmly clamps the cord in the recess so as to resist any undue strains imposed on the extension cord. The clamp bar 48 is preferably arranged inside the housing and is secured in position by the screws 49, 49, threadedly engaged therewith and passing through the extension 46 of the porcelain mounting 34.

By the arrangement of parts as just described, the heater unit affords the maximum protection to the functional parts thereof, while at the same time, the parts are unusually simple and may be manufactured at relatively low cost. Moreover, the heater unit is virtually tamper-proof, yet the functional parts thereof are conveniently accessible for purposes of repair or replacement when this is required.

The heater unit 2, when fully assembled, may be conveniently mounted on the frame I by placing the same in position on the flat supporting surfaces afforded by the rim H and central extension l3 of the frame, the former engaging the outer marginal flange or wall 24 of the heater housing, and the latter engaging the inner tubular extension 23 of the housing which depends from the vulcanizing surface I8. The upstanding flange [2 at the outer margin of the rim H of th frame I assists in accurately positioning the heater unit on the frame, with the central opening 2| in the heater unit aligned with the opening 8 in the frame. When so positioned, the heater unit may be attached to the frame by the screws 50, 50, which pass through the horizontal rim ll of the frame and are threadedly engaged in enlarged bosses 5| formed on the inner face of the outer marginal flange of the heater housing. These bosses are preferably made of ample size to resist the setting up of undue strains in the heater housing when the bolts 50 are tightened up to clamp the heater unit to the frame l. Two such clamping bolt have been found to be ordinarily sufficient, although the number may be increased if desired.

As an additional precaution against the transmission of heat from the heater unit to the vulcanizer frame, an asbestos gasket 52 may be interposed between the lower end of the outer marginal flange 24 of the heater housing and the upper side of the annular rim H of the vulcanizer frame I. A similar gasket 53 may be interposed between the tubular extension 23 of the heater housing and the tubular extension 13 of th vulcanizer frame. It is to be understood, however, that these gaskets are not essential, since the special construction of the heater unit itself is such as to minimize the transfer of heat from the heating coils 28 in a downward direction.

In the use of the vulcanizer, after placing the rubber valve stem and the inner tube in the positions as shown in Figure 1, 2 and 4 of the drawings, the platen-supporting arm 5, which is pivotally connected to the frame I by the pin 6, is moved in a counter-clockwise direction, as viewed in Figure 1, to a position permitting the pivotal abutment lug 54 to be engaged beneath the abutment 55 on the arm 5, following which the pressure screw 4 is screwed down with the aid of the hand wheel 56 to firmly clamp the inner tube and valve stem against the vulcanizing surface l8 of the heater unit 2. The vulcanizing operation may then be performed by energizing the heater unit which may be connected to any convenient outlet plug by the extension cord 42. On completion of the vulcanizing operation, the pressure screw 4 is unscrewed for enough to allow the pivotal abutment to be disengaged from the abutment 55 on the platen supporting arm 5, whereupon the platen supporting arm, together with the platen 3, may be swung upwardly to the dotted line position shown in Figure 1, following which the work may be removed from the vulcanizer. Manipulation of th pivotal abutment 54 to and from its cooperative position with the abutment 55 is accomplished through the knob or handle 5! formed on one end of the pivot pin 58 on which the abutment 54 is fixed for rotation with this pin, the pin 58 in turn being free to rotate in the vulcanizer frame I.

In addition to use for vulcanizing rubber valve stems, the vulcanizer may be adapted for use in vulcanizing flat patches, as more fully described in the prior patent hereinbefore referred to.

While the specific details have been herein shown and described, the invention is not confined thereto, as changes and alterations may be made without departing from the spirit thereof as defined by the appended claims.

What we claim is:

1. A vulcanizer of the class described, comprising a frame including a hollow tubular part arranged with its central axis in a vertical position, said tubular part being provided with an outwardly and upwardly inclined Wall extending about the upper end of the same and terminating at its upper end in a horizontally disposed flat, continuous annular rim radially spaced from and at the same level as the upper end of the tubular part, a heater unit mounted on the frame, said heater unit including a circular housing of inverted cup-shaped form, the upper side of said housing constituting a vulcanizing surface, with its outer marginal wall depending from the vulcanizing surface and resting upon the annular rim of the frame aforesaid, said heater unit also having a central opening therethrough aligned with the tubular part of the frame and having a central tubular hub surrounding the opening and depending from the vulcanizing surface, with its lower end resting upon the upper end of the tubular part of the frame, and a pressure platen carried by the frame in cooperative relation to the vulcanizing surface of the heater unit.

2. A vulcanizer as defined in claim 1, wherein the upper end of the tubular part of the frame and the surrounding inclined wall are each provided with apertures laterally communicating with the interior of the tubular part aforesaid.

3. An electrical heater unit comprising an annular housing defining an unobstructed central opening therethrough and provided with an outer marginal flange thereabout and an inner flange around the central opening aforesaid, said flanges defining therebetween an annular space, a heat ing element disposed in the annular space aforesaid and electrically insulated from the housing, closure means including thermal insulation arranged in the annular space beneath the heating element, thermostatic means also disposed in the annular space and within the housing and including an insulated mounting extended laterally through the outer marginal flange of the housing, and a conductor cord rigidly fixed to the insulated mounting and electrically connected in circuit with the heating element and thermo static means, said thermostatic means and conductor cord being both attached to the mounting within the housing of the heater unit, and the mounting being attached to the housing independently of the heating element.

4. An electrical heater unit comprising an an nular housing defining an unobstructed central opening therethrough and provided with an outer marginal flange thereabout and an inner flange around the central opening aforesaid, said flanges defining therebetween an annular space, a heating element disposed in the annular space aforesaid and electrically insulated from the housing, closure means including thermal insulation arranged in the annular space beneath the heating element, thermostatic means also disposed in the annular space within the housing and including an insulated mounting extended laterally through the outer marginal flange of the housing, and a conductor cord rigidly fixed to the insulated mounting and electrically connected in circuit with the heating element and thermostatic means, said thermostatic means and conductor cord being both attached to the mounting within the housing of the heater unit, and the mounting being attached to the housing independently of the heating element and thermally insulated from the latter.

PAUL SCHMID. HENRY I-IYL'ION.

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