US2021509A - Resistance device and unit therefor - Google Patents

Description

Nov. 19, 1935. D. F. YHASTINGS 2,021,509

RESISTANCE DEVICE AND'UNIT TBEREFOR Filed Jan. 9, 1934 miiiMWNNWWMWNW Y 5g INVENTOR Joya/i ftgas r gs ATTORNEY resistance device and While I am aware LNL ,JUU

UNITED STATES ATENT OFFICE spruce f nssrs'rsncsnnvrcs AND nm'r macro Donald F.

nastinsa Fairla 1., illigllor to Hardwick, Kindle, Inc.,- Newark, N. J. Application January 9, m4, Serial No. 195,869 [Claims- 7 (Cl. 20 1-63) This invention relates to an improved form of unit therefor. that resistance units and devices have been made in mamr ways, yet I be- 5 lieve the structure shown and described herein includes a number of advantages not present in prior art devices with-which I of the objects of duce a compactwire-wound resistance unit of It is one am familiar.

my invention to prorelatively high resistance value.

Another object of my invention is to produce a compact wire-wound resistance unit which will dissipate a relatively large amount Another object of my of power. invention is to provide a resistance unit which can be easily and cheaply made, yet one that is rugged in construction and will therefore stand much abuse in operation.

a new type of resistanc in handling and invention is to provide sembled in groups to make up a resistance de ice which willtake up a yet which minimum -amount of space, will have a high wattage rating due to the large radiating surface with respect to volume attained by my construction.

These and other objects will be apparent to one skilled in the art of constructing resistances,

after reading the Figure 1 is a plan units without the outer specification tion with the annexed drawing,

view of one of my resistance taken in conneccovering applied thereto.

Figure 2 is a longitudinal section on the line 2-2 of Figure 1, but with position. Figure Figures 1 and 2. Figure=4 isa the outer covering in device composed pianview of a modified form of plate which maybe. used as aterminal and binding plate. 1 Figure 5 is ure 4.

a section lizure 6 is a plan view winding which may be tionof the complete unit diagrammatic illustration show- Figure '7 15'8- on the line of Figof one form of resistance utilized in the construcing the manner'in which the resistance winding I of Figure 6 may be assembled between the binding and terminal plates Figure 8 is a view somewhat similar to Figure 5,

showing a different way of making. contact with such plates will act to tribute the'heat over plate-of the resistance unit. and 10 show modlfled forms cf terminal and binding plates.

1' and ;quickly collect and disthe-surface of the unit,

' dissipated. Between the units as shown in as above described;1they'-m .to the terminal plates and hen next adjacent unit, andthe preferably of lnsulatingmat 2 are flat metallic" plates preferably of soft copper, for the reason very good conductor of heat andthe nee? whereby the heat from the winding is rapidly I plates 1 and 2 there is located a resistance winding 3 wound on a flat form 4 of heat-resisting material such as a sheet 'of mica. The plate I is prevented from contacting with the turns of the winding 3 by an insulator 5, and likewise, the turns of the winding 3 are prevented '2 by an insulator preferably of good heat-resisting material such fromeontacting with the plate 6. The insulators 5 and 6 are as mica.

,To hold the plates l and 2 in position over the insulators 5 and 6. and the resistance winding 3, the plate 2 is provided withiingers 1 andilwhich are bent upwardly and lie on the-* insulator 5, leaving a space ii which is provided by'notching out the corners of the plate I. "Likewise, fingers 9 and Iii are positioned on the bottom side of the unit in a similar manner. The plate [is provided with a terminal extension Hand the plate 2, with a terminal extension IS. The extensions i2 and It may be each provided with an eyelet, it which also serves to clamp the ends I of'the winding, one end 55 being shown, as each vitreousenamel, with the ei'tception of the iaised portion 16 and that portion of the terminals I2 35 and it around the eyelets ll The enamel bridges over the spaces I l and completely seals the whole unit, thus renderingthe same] substantially moisture-proof. A'ftcrf tli'mnits ar e completed aybeassembl'ed in any 40 use f-of the eyelets It for moking'connections otheTextremi-ty satisfactory manner. by. which may also be used of the resistance winding. In addition, the units"iri'ay' be assembled as 5 shown in glgure 3 by stacking a plurality of units in a substantlallymeehanical, parallel relationship, whereby the rais f is in contact with the ra" in assembled relationin any satisfactory manher as by a mounting t mpo t. i upright supports It and I l-oneof which, such as ll. carries a-clamping'j' rew'jfl forfclaniping 55 positionand for making electricai connection throughthe the post-2i to the'bindin g post :2. By reference-to that fiit fi iay be d .50.

.co c nsuptotheenamelingofflieunits '-In'some,cases,rmay1uetheside fingers".

2 a a,o21,goe

resistance and any one of the units maybe used independent of the others by connecting the terminal wires directlyto the terminals l2 and I 3 of the unit desired, instead of to the binding 5 posts 2! and 22; or one side of the circuit may be connected to both the binding posts 2| and 22 and the other circuit wire connected to any one of the terminals l2 and II of the different units, thereby giving a series parallel arrangement of the resistance units. In addition, one side of the circuit may be connected to either one of the terminals 2| or 22, while the other side of the circuit may 'be connected to any one of the 1 terminals 01' the various units, thereby providing what is generally referred to as a tapped resistor. I

In Figure ,4, I have shown a terminal and binding plate I with the binding lugs 9 and II and raised portion l6 as in Figure 1, but the terminal I2 may be provided with an integrally formed eyelet 23 around which one terminal end of the resistance-wire 24 may be wound, and then the eyelet 23 is spun over or forced into position to clamp the wire 24. While I have shown an in- 25 tegral eyelet 23,- it is to be understood that a separate eyelet may be used at this point if desired. This construction leaves a hole 2| in the terminal l2 for ease in soldering-a connecting wire thereto, or for mounting purposes, in which case the terminal wire may be wound around the terminal 2 at the V-shaped Junction point 2!.

Instead of a single form 4 carrying the resistance winding 2, I may use a plurality of 3 windings 3 all wound on a unitary form 21 which has slots 28 punched therein before the winding 3 is applied thereto as shown in Figured.

By constructing .theforin 21 in the manner just described, the form may be readily folded uponthelineoftheslotsflasahowninl'igure 7, without any danger 'of breaking the winding at these bendable points, insulators as being utilised between the various windings I of the unit structure. After the form has been folded up as shown in Figure 7, the extremities of the winding are connected to the plates l and. 2 which are applied and fastened in position as has been described.

clamped over the stack andinto thespsees s2 providedontheplatelasshowninligurelit so being understood that the fingers II and the spacesornotchesflaresuchthattheflmersfl willnot'touchanyportionoftheplate 2, This construction tends to preventany weaving ofth'e plates I and '2 during the which are indicated by dotted line in connec "tion with the plate I, v

adapted to be positioned inclearance notches I4 7 indicated by dotted lines in l'isure' ll.

From what has been said, it will be understood that the type of resistance unit herein shown and described, will radiate a considerable amount of heat; that is to say, the wattage rating of the '75 unit isrelatively high. .This feature is especially useful when the units are arranged in a com.

- pact space as illustrated in Figure 3. Furthermore, the construction of the unit is such that if one should burn out in an arrangement such as shown in Figure 3, this unit may bereadily 6 and quickly replaced by a new unit.

While I have shown a series of sections wound on a single bendable form 21, as in Figure 6, it is to be understood that a number of individual sections as shown in Figures 1 and 2 may be 10 stacked between the binding plates I and z, and

plates positioned on and overlying the faces of 20 the opposite sides of the unit against said lastmentloned insulators, said plates being provided with means for locking themselves in position over said insulators, and means on each plate for connecting an end of the winding securely. there- 25 to, said unit having an outer covering of baked vitreous enamel.

2. A resistance unit as set forth in claim 1, characterized in that the central part of eachof said plates has a raised uncovered portion for the purposes described. I

3. A resistance device consisting of a relatively flat stack or elements including a pair of metal-, lic binding plates having portions bent over the stack to form a self-lock and also having termi-- nal projections, a resistance winding positioned between but insulated from said plates, ,said winding being wound on' a single elongated flat form of heat-resisting material having connected but foldable sections, that part of the winding on so one section being I parsted by a suitable insulater from the next adjacent section winding when the sections are folded up for placement between ssid metallic plates. and an outer covering of baked vitreous enamel over the whole device 4 except at least the ends of the terminal probe- 4. A including amounting having circuit terminals, said mounting-carrying a plurality of resistaneeunits, each unit inciudl0. ingafiatstachofeiementsandapairofmetaliic bindiu plates having self-locking portions ex- ;tending over opposite sides of the stack and also having terminal projections, and at least one resistance woundonafiatformtolie" between but insulated mm mo plates. the ends of the winding-being connected betweensaid plates, ch plate having an mull'llflat raised connscfsd'in series. and eachunlt being covered 7 with a baked vitreous heat-resisting material expt for said raised portions and the endsof said terminals 5. A resistance device including a plurality of. resistance units as defined in claim 4 in which the units are arranged in mechanical parallel relationship with thecentral uncovered portions in contact, means being provided for holding said units in said position whereby the units may be readily connected in series or series parallel relationship, or any one of the units may be used separately, or the units may be used. or connected as a tapped resistor.

DONALD I". HASTINGS. 76

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