US2472738A - Terminal block - Google Patents

Description

C. B. BACKER l ERMINAL BLOCK June 7, 1949.

Filed Dec. 4, 1944 plate -adj acent its edge. which may be directed straight downwardly or downwardly and slightly outwardly (away from Patented June 7, 1949 Application yDecenib'er 4, ISK-'Serial NOJ56=A64 :Inlv Ganadaf Decembenlylwzi This invention relates to-electricheating plates `such a-s are used in domestic kitchen ranges and the like, and more particularly to that type of range plate which employs a heating element comprising one or more tubular members.

In the design of a range element utilizing tubular members, the arrangement of the terminals ythereof has always presented many problems. In

some instances, the ends of the tubes are simply bent downwardly and passed through a protec- -tive sheet metal reiiector plate to which the tubes .may be clinched so as to make a water-tightjoint `and thereby prevent over-boilings from running .onto the terminals. While thisarrangement isi-a simple one, it renders quite difficult theI cleaning of the reflector plate and, moreover, should' one of the usualv two tubular members burn out the Whole element must be discarded since it i-s impractical to remove and replace one of the members. Another disadvantage of this arrangement is that, unless the downwardly extendingends -of `the tubes are very long (which often is not permissible because of lack of space), the terminals become very hot, which results in deterioration and breakage of the copper lead wires connecting the element to the switch.

To produce a tubular range element in which the reector plate is readily removable for cleaning purposes, it is necessary so to arrange the tubes that their ends are located adjacent-the ledge of theV unitary element and are bent downwardly through a cutout opening in the reflector The ends of the tubes,

the heat), are usually passed through a terminal shield or cup, which is intendedA to protect the `terminals against overflowing liquids, but which invmany instances fails to accomplish thism portant function.

An4 object of the present invention is to provide l a unitary range element of the tubular type wherein the terminals are located in such a position that they are substantially unaffected by heat and overflowing liquids, wherein the reflector plate may be readily and quicklyv removed for. cleaning purposes, wherein the entire unitary elementmay be conveniently detached from the rangeby an unskilled person, wherein a burnt out tube member may easily be replaced in the field, without disturbing the other parts ofthe .element and without tools other than a simple tool such as a screwdriver, and wherein there is 'provided an improved but inexpensive and ecient supporting means for the tube members.

The invention willgbe described with particular vreferenceto the accompanying drawing, in which Figure 1 `-is a plan view of a heating element in accordance with the invention, as detached ,fromara-nge structure,

Figure` 2V is a sectional elevation of the heating r,elementas located in a range structure and including .a terminalfbox,

Fig-ure is atop view of the terminal box, fEig-ure viis a bottom view, partly in section of ,the terminal box,

Figure 5 kis aside elevation, partly in section, etz-the' terminal box,

Figure 6 is a sectional View' of a terminal box Figure Tis a partial sectional view of the heatr,ingelement Ishowing a modified form of clamp- :ing means, and

.-lligure isapartial plan view of the clamping meansshown in Figure '7 yWhile theelement may comprise one or more ntubular members1 it is usual to provide two such :members Two tubes are illustrated in the form pshew-n-ginthe drawing, I being an outer tube in circularform, and 2 being an inner tube having anplurali-ty of bends and curved portions. Such "a tubearrangement provides a unit with the desirable hot-centen that is, the element may be Ieconomically used on medium load with small ycooking vessels. The tubes contain the usual resistance mem-berk A support 3, usually known `nas a spidenhaving four radially extending arms, as showrris provided forthe tubes. Spiders of 4this 'GypelhaVe-heretofore generally Ibeen formed of steel with portions thereof partially embracing `-tire-tubesfto hold the latter in position. In accordance withfone feature of the invention, the

.spider -may be formed of Cast iron, each arm :thereof having arib 5 extending along its upper surface `with tube-supporting piers 6 formed ther-ecm The upper surface of the piers t, on

whichl the tubes rest, must of course be located in the san-ieri plane, this being preferably accomplishedby-submitting these surfaces to a simple grinding operation whereby all such surfaces are l-sinmltaneouslyiground to the same level.

`Means for clamping the tubes firmly in position on the spider but for ,convenient and rapid `vdetachment therefrom, when desired, comprises ,a clamp I1 positioned adjacent the end cf each arm 'of the spider. Each clamp consists of an outer .U-shaped clip or saddle 8 adapted to receive the tubes and an inner U-shaped clip 9.

,Asjshwm the inner clip ts within the outer clip, 'a 'portion of tube I being engaged by the spaced arms of the clips at one side while a portion of tube 2 is engaged by the spaced arms of the clips at the other side. The edge of each arm of clip 9 is preferably flared outwardly, as indicated at l, to fit around the sides of the tubes and thereby provide a firm fastening means for the same. The clips are mounted on a boss 40 formed on the spider, and a screw Il secures the same thereto. It will be observed that, with the screws of the various clamps in tightened position, the two tubes will be held firmly on the spider. However, either tube may be readily slipped out of its seats in the clamps and separated from the spider simply by loosening the four screws II without, however, entirely removing such screws. Thus, no part of the clamp need be completely removed from the assembly and danger of loss of parts is avoided. The clips 8 and 9 and screws Il are preferably formed of stainless iron to resist rusting.

Referring to Figures "1 and 8, an alternative means is there illustrated for clamping the tubes to the spider. Instead of the saddle t, a pair of upright pins Sii are provided to engage the sides of the tubes. fixed in bosses il formed on the spider, as by driving them into tight-fitting holes bored in the bosses. Instead of the clip 9, a cup-Shaped member 38 is preferably employed. This cup 38 has an outwardly flared edge 38 to provide snug engagement with the upper wall portions of the tubes. The clip 33 is mounted on a boss 39 formed on the spider, and a screw il secures it thereto. A disc or washer l2 is preferably provided on the screw below the clip. This disc is mounted in fixed relation on the screw whereby the clip is always held in engagement with the head of the screw. Thus, when loosening the screw, the clip follows upward movement of the head thereof and disengagement of the tubes from the clamp is facilitated. Since the clip is cup-shaped, rotation thereof does not affect its clamping position. Moreover, since the upper surfaces of bosses 3l and 39 are in the saine plane as those of piers 6, a single grinding operation only is required to level all these upper supporting surfaces of the spider. In the form shown in Figure 2, for instance, a second grinding operation would be required to level the supporting surfaces of bosses flii, which are in a different plane fromthat of the upper surfaces of piers 6.

The element assembly is suspended from the main frame I2 of the range by means of an annular frame I 3, which also supports the reflector plate I4.

It will be observed that the four ends of the tubes are located in adjacent relation. As shown, these ends, indicated at I5, are firstly bent downwardly to extend through a cut out opening i6 in the reflector plate. The ends are then bent in an upward and outward direction, as clearly shown in Figure 2, whereby the extremities thereof are located substantially entirely beyond the periphery of the element. With the ends in this position, they are completely out of range of liquids overilowing on the element as well as of high temperatures of destructive range to the terminals and associated parts. It thus becomes feasible to employ terminals of the plug-in type in such a structure. Terminals of this type are of little practical use when exposed to considerable heat or to even a small amount of overflowing liquid, since the resulting sticking of the terminal pins in the socket makes disconnection diiiicult if not impossible.

The pins 3G are securely The ends of the tubes are therefore preferably provided with plug-in type terminal pins Il.

The terminal box illustrated comprises a porcelain block I3 having a sheet metal housing I9 providing protecting back and two side walls for the block.

Means for clamping the tube ends to the housing comprise a U-shaped bracket 26 having its body portion fixed to the housing wall immediately below the porcelain block. Four aligned openings 2l are provided in either arm of the bracket and through such openings the four tube ends project. A bar 22 positioned between the arms of bracket engages one side of each tube. A pair of clamping screws 23 extend through the bar and have square nuts 24 each of which fits between and engages a pair of tube ends adjacent their other sides. It will be observed that tightening of the screws will firmly secure the tube ends to the housing while loosening of the same will render it possible to withdraw the ends. in this clamping means also, it is not necessary wholly to remove any of the parts thereof from the assembly during the loosening and tightening operations thereof.

The terminal pins il are adapted to enter sockets formed in the metal members 25, which are housed in the 'terminal block, as shown. Each member may be square in cross-section, as illustrated in Figure 6, its lower portion being preferably split, as shown. The usual insulationcovered copper lead wires 2l are connected to the upper ends of the members 2t. These lead wires are clamped firmly to the block by means of the U-shaped clamping bar 23 with clamping screw 2S.

Since the terminal pins may be diiiicult to withdraw from their sockets, especially if they have remained therein for a long period of time, means are preferably provided to ensure easy manual ,vithdrawal of such pins. This means comprises a lever 35i having a pair of arms 3| adjacent to and pivote'd to the side walls of the housing I9 by means of the shaft E2. An operating bar 33 connests the two arms, The arms have forwardly extending portions M which i'lt into respective recesses 35 in the ends of the porcelain block. The upper edge of each portion 3ft engages the upper side wall of the recess 35, as clearly shown in Figure 5, the operating bar 33 being thereby positioned angularly with respect to the back wall of the housing. lt will be observed that, by grasping the bar $3 and back wall of the housing and pressing them towards each other, the porcelain block will be moved relatively to the housing whereby the pins will be withdrawn from their sockets.

There has thus been provided a range element with terminals so arranged that they are not subject to injury by overflowing liquids or excessive heat. Moreover, the arrangement described lends itself to the elicient use of plug-in type of terminals. The entire element may be quickly and conveniently removed from the range by any person without the use of tools, should it be found necessary to forward the same to a repairing establishment. On the other hand, either or both of the tubular members may be quickly replaced in the field simply by loosening the four screws l l and the two screws 23.

The .reflector plate may be readily removed for cleansing purposes by slightly lifting the right hand side of the element (with the spider) from the frame is, whereupon the reector may be slid out. It will be realized that this slight lifting of one side of the tube unit will also cause the terminal block to move slightly during this operation. However, this movement will not impose any strain on the copper lead wires 21 because of their firm attachment to the block by means of the clamp 28, 29.

It will be understood that various changes in the details described may be made without departing from the spirit and scope of the invention as dened in the appended claim.

I claim:

In a plug-in type of electric range element having at least one tubular member, a terminal block comprising a, substantially inclined porcelain block, a metal housing on the porcelain block, and means for clamping the ends of said tubular member to the housing comprising a U-shaped member having a body portion xed to the housing and a pair of spaced arms having aligned openings therein to receive said ends,

a bar positioned between said arms and engaging one side of said ends, and a screw having a head engaging said bar and a nut thereon engaging the substantially opposite side of said ends.

CHRISTIAN B. BACKER.

REFERENCES CITED The following referenlces are of record in the

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