US2052644A

US2052644A - Rubber heating unit

Info

Publication number: US2052644A
Application number: US752656A
Authority: US
Inventors: Murphy Morton
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-11-12
Filing date: 1934-11-12
Publication date: 1936-09-01
Anticipated expiration: 1953-09-01

Description

Sept. 1, 1936. M. MURPHY RUBBER HEATING UNIT Filed Nov. l2, 1934 /phy ACL'ome/ys.

Patented Sept. l, 1936` aman HEATING UNrr Manon Murphy, Indianapolis, rnd.'

Application November 12, 1934, semi Np. 152,656 1 claim. (c1. zia-4s) This invention relates to electrical means for applying heat to various parts of ones body. A primary object of the invention is to provide means whereby an electrical heating element may be employed to be placed in close proximity to the skin without the danger of electrical burns or' shock should the carrier of the element become wet or should the element break within the carrier. Electrical heating pads have been employed for some time wherein the element was carried within some cloth or. textile member and such a pad has become to be recognized as dangerous in that a slight molstening thereof places theelectrical circuit in direct connection with the user and furthermore should the circuit develop, there is great danger of fire. The heating element must be flexible in order to permit the pad to conform to the contour of the surface to which it is applied and this means that the element is subjected to much bending which in itself tends to wear out the element and cause it to break.

My invention consists essentially in embedding a resistance wire of relatively small diameter within rubber so that the element is at all times electrically insulated as well as being ventirely enclosed and covered over against the entrance or access thereto of moisture. By means of the rubber carrier, particularly in the form of a heating pad, the pad is exible so as to permit its conforming to the contour of the surface over which it is'applied. Another advantage of my invention is that it may be manufactured at a relatively low cost and still preserve the objects and advantages above indicated with perfect safety to the user. f

Further objects and advantages of the invention will become apparent to those versed in the art in the following description of the invention as illustrated by the accompanying drawing, in which Fig. 1 is a top plan view of a pad embodying my invention with part of the upper sm'face broken away; l

Fig. 2, a vertical transverse section on the line 2-2 in Fig. 1; A

Fig. 3, a front elevation of a pad embodying my invention in a modified form;

Fig. 4, a vertical transverse section on the'line 4--4 in Fig. 3;

Fig. 5, a top plan view of the form shown in Fig. 3;

Fig. fi, a vertical elevation in partial section of a heating unit for internal use, and

Fig. '7 a transverse section on the line 1-1 in Fig. 6.

Like characters of reference indicate like parts throughout the several views in the drawing.

Referring first to the form of the invention as illustrated in Figs. 1 and 2 showing a heating pad, I take a sheet I0 of uncured rubber and press it down over a plurality o'f pins II. These pins Il are. properly located so that a length of resistance wire I2 may start by one end as at I 3 and then be carried therearound to form loops on one side of the center line and then carried across and around under those loops to the other side and looped back and forth to be carried around by its other end I4 to terminate adjacent the first end I3. Conducting wires I5 and I6 are connected to the respective ends I3 and Il, these wires I5 and I6 being preferably embedded and covered by rubber to form the customary rubber insulated cable. This cable is so placed as to have the rubber insulation thereof lapped over on the sheet l0 adjacent the wire ends I3 and I4. I then -apply a second sheet of uncured rubber I1 over one to the other to form in effect a resultant singie thickness of rubber within which the resistance wire I2 is embedded nearer one outer surface than the other.

The resistance wire I2 is preferably in a coiled form, although not necessarily so. The coiled form is preferred on account of the fact that it permits of a more exible pad and when the pad is folded or twisted around, the wire itself is not so likely to break. The relative thicknesses of the sheets I0, I1 and I B as indicated in Fig. 2 are somewhat exaggerated in the drawing in order to clearly show the structure. overlaps the rubber4 insulation of the cable including the wires I5 and I6 so that the end of the cable is vulcanized between the sheets I0 and I1 to have its insulation become an integral part thereof. By reason of the single sheet I0 on one side and the two sheets I1 and I8 on the other side of the heating wire, the pad at once provides two heats". That is on the side of the pad having but the one sheet I0 covering the wire I2, more heat will be transmitted than on the other side where two sheets cover the wire The sheet I 1 2 t. i2. 'Ihus by merely turning the pad over, application of heat may be varied.

In the form of the invention as shown in Figs. 3-5, I have provided a pad i9 here shown as hav- 5 ing a. marginal forwardly projecting ange 2t with a cable 2i leading from the center. The pad I9 is formed in the same manner as above described .in reference to the pad shown in Figs. 1 and 2 to have a heating element 22 embedded 10 within rubber. lThe pad 'i9 is so formed as to proportions and dimensions that it may be inserted within a patients mouth to have the upper portion of the pad in contact with the upper teeth and gums and the lower part incontact with the l5 lower teeth and gums. The pad in use assumes the shape somewhat as indicated by the dash lines in Fig. 5, they pad being suiciently exible and elastic to permit its being inserted between the the cheeks and the teeth. The marginal harige 2dserves to space the cheeks away from the pad and thereby prevent undue heating or burning of thev cheeks, thus permitting without discomfort. an application of heat at a temperature well above body heat to the patients gums. Where heat is to be applied internally, the resistance wire 2t. Figs. 6 and 7, may be wound about an uncured rubber core 2d and the'n a sheet ci uncured rubber 25 wrapped therearound and vulcanized to the core t6 within a suitable mold so as to form. an integral rubber carrier with the heating wire 23 relatively close to the outer surface. The

, rigidity of the unit is determined by the rubber mixture employed. l

It is to be seen that in any one of the above indicated forms which are only a few of the possible many forms the invention may assume, the

heating element is directly embedded within a rubber carrier to have the element close to at least one side thereof, but thoroughly insulated 40 against moisture as well as electrically so that the pad er neung unitwin be used in perfect safe- `ty under all conceivable conditions. I nd that by properly proportioning the heating element in the various units, I can secure a transmission of heat of desired amount without in any way aiecting the rubber carrier. It is of course essential to have a. suihcient amount vci. wire in the heating element so that no local area thereof becomes heated to that temperature which will damage the surrounding rubber. The heating element is directly embedded within the rubber without any intervening fabric or other insulating medium. Since the cable leading the conducting wires from 'the heating unit is molded and vulcanized in the unit to become an integral part thereof, there is no danger of break-down or water leakage at the connection of the cable with the unit. y

While have herein shown and described my invention in the form now best known to me, itis obvious that structural changes may be made without departing from the spirit of the invention and I, therefore. do not desire to be limited to that precise form beyond the limitations as may be imposed by the following claims.

i claim: .a exible elastic heating pad comprising a length oi spirally wound resistance wire looped between two sheets of rubber vulcanized one to the other to '.,iftend between the spiral windings and loops of the wire, said wire being in direct contact with the rubber and stretching therewith by reason of said spirally wound arrange ment, said wire being wrapped around a plurality ci pins located so that a length of wire starts at one end of the pad and is carried thence around forming loops on one side ci the center line of the pad and then carried across the pad under these loops to the other side of the pad and looped back andforth to form loops on 'the other side of the center line of the pad and terminating adjacent the iirst end.

Q MORTON MURPHY.