US2020289A

US2020289A - Resistance unit

Info

Publication number: US2020289A
Application number: US671432A
Authority: US
Inventors: Frederic H Bullinger
Original assignee: Ward Leonard Electric Co
Current assignee: Ward Leonard Electric Co
Priority date: 1933-05-17
Filing date: 1933-05-17
Publication date: 1935-11-12
Anticipated expiration: 1952-11-12

Description

Patented Nov. 12 1935 REBISTANCE UNI'J.

lreclerlc H. Bullinger, Brimxxllle, N. Y. uaignor to Wud Leonud Elecirlc (lonunny, a corpoutlon otNew York Mnflhnflon nu 17. 19:3, SGll&l N0. 071.43: Chinas. (Ch zo 1 as) 'I'his lnvention particularly relates iso an improved tubular resistance unit und method ot making the same wherein the reeisi:ive conductor is wound 011 a hollow insuiating tube end in which the tube also'senes to carry the terminels to which the resistive conductor is connected.

'I'he mein object oi' the invention is to produce a resistanoe unit o! the tubular type which is adapted to be rea.dily manufactured a.t companl0 tiveiy low cost, while, at the sa.me time. producing an article which is dependable in Ion: continued use end satisfactory in various other oommercial requirements. 'I'he economy in cost oi' production is secured not only by convenience und rupidityi-S inmaking, but also by use ot e form 01 terminalconnection which permits the cool: o! materla.l tonning the terminai connection to be low. Another object is to provide a. Ion-m o! ter'miml umnection which, although simple in character. will 20 not be displaced er disturbed in ordinuy nasse end which will form a. permanent good electrical eoxmection with the resistive oonducinor. Another objectis to avoid the use oi my cloaed circuited coiljor band around the tube in forminzhe ter- 25 mina.l connection or connections, es auch commonly used coils or bands ere alten objectionnble when the resistive unit in uaed in connection with high'irequency apperetus. Another object is to provide a resistive unit which will lnve a smooth 3') end plea.sing eppeqrence withou t objectionnble protuberances. Other objects end advantages o! the invention will be understnod by those skilled in the art fromthe ioliowing desc'ription und accompanying dre.wing which illustretes preterred embodiments o! the inventlon.

I"igure 1 is a. longitudinal lecti0n 01 a ux'xit showing the mounting 01 the terminals thereip. Fix. 2 in an end view ot the structure shown in Fig. l. Fix. 3 is s bottom view 01 the structure 40 ahown in I"ig. 1 end also showinz the resistive canductoripplied to the tube end connected to the terminals. Fix. 4 is a side view oi the completed unit. Fix. 5 is a side view showing the resistive conductor on the tube und connected to a difler- 43 eni: part 01 the lead irom thai: 5hown in Fix. 3 und -oppbsite. A bendable ieadis used which passe:

through oppositely located holes in the tube end.

in order to hold the sa.me in place on the tube. the iead i.s bent at the inne:- surface o! the tube so a.s to form a loop for holding the same in position. 5 Thusaleadinligs. land2isshownatlinthe i'orm 018 a. copper wire having an unter end 2 In: convenient oonnectiou 1:0 other devices or conductors. 'I'his copper wire is shown es paasinz through two opposiizely located holes near the end ot the tube l andisbentwithinthehxbetotorm a. loop 2. 'l'his bend or loop in thewire-is sufliciently pronounced to insure the lea.d being held in place on the tube und may be i'onned by pushing e cone-shaped tool in the end cf the tube. or otherwise.- One end 2 01 the wire terminal ls shown pr0iectin: a little beyond the suriace o! the tube ior connection thereto oi' the resistive eonduciaor. At the opposite end o! the tube in shown another lea.d wit 'e I hflinl the Wndin: perts 3. I end 1. 1

Fix. 3 shows the resistive conductor l applied to the insuletin: support Dein: wound thereon und havin: its ends connected tothe leacl wires.

Ili epplylnz the reaktive donductor. oue end thereoiisgivenatewturnsaround theend3 01 one o! the terminals und then i.s wo1md wund the tube intheusalwutotheendloftheotherterminnl andiscivenafewturnsamundthisendsoasto be secured thereto. In order to serve es a. guide for the ends oi' the resistive conductor. & murow slot 5 i.s tormed circumierentially on the insulating tube end ecross the openings which receive the ende 2 und 3 01 the lea.d wires, these slots being cut in the taube betone the ieed wires ue placed in position. Tims when the end o! the resistive conductor is wrapped around the end 3. the conductor then nasses through end is lodzed in one portion 01 the slot 5 es it passes trom the end 3 around the tube. Similariy when theend 40 o! the condudtor reaches the other end 01 the tube lt will pa.ss in incl thxough one portion o! the slot 5 end then be wrapped around the end 2. These guiding 'slots i'or the! registive conductor are not essential but ere convenient tor pro:ierly locating und directing the conductor. 'lhe slot in also utilized in hold the end 01 the lea.d in plaoe. l'ho ends 2 und 8 a.re preterably flattened so es to i'.lt snugly in the slots, thereby preventing a.ny movement ot, the lead which might breal: the resistive conductor during oi alter the process 01 manutacture. After being thus assembled, theresistive conductor i.s preierdbly soldered to the lead wirea havlng a comparatlvely hlgh melting point, such as a high temperature silver solder.

I'he unit is next covered with an lnsulatlng coating on the external surface of the tube so as to insulate and protect the resistlve conductor from mechanical lnjury and moisture in the usual way. This coating ls preferably an adheslve vitreous enamel as it firmly adheres to the parts, has high lnsulating qualities and ls lmpervlous to moisture. The enamel material alter belng applied to the unlt so as to cover the

small projections

2 and 3 and also the base of the lead wires where they extend outwardly from the tube, ls matured in a Iurnace to produce the flnlshed product, such as shown in Flg. 4. The external surface of the tube has a smooth appearance wlth only slight projections where the connectlon 01 the resistive conductor ls made at the

ends

2 and 3.

Instead of connecting the resistive conductor to the and 2 or 3 of the lead wire, the conductor may be connected to the lead at the point where the mein portion leaves the taube. Thus in Flg. 5 the resistive conductor is wrapped around the lead 3 at the polnt 1 and soldered theteto and similarly a1; the.point 8 of the lead 2. Likewise, the slot 5 would be Iormed in the tube at the polnt where the mein part 015 the lead leaves the tube, for guidlng the resistive conductor and holdlng the flattened lead in place. In the iorm shown in Flg. 5, the projectlng ends, such as 2 and 3 are avolded so that the tube at such points has a smooth external appearance without any materlal projections. Thls form o1 tube in completed form is shown in Fix. 6.

Alt-hough I have shown the leads located at the -ends 01 the tube, lt is evident that one or more may be located at intermediate polnts along the length of the tube and the reslstlve conductor connected thereto, as already described, where lt ls desired that the unit be supplied wl th taps. It will also be understood that instead oI the leads, such as 2, 3, belng formed of a solld copper wire, they may be 01 other forms 01' of other material; likewise the termlnal instead of havlng outwardly extended portlons for connectlon to an external circuit, may be connected to other forms 01 external termlnals and serve as anchorlng means or intermediate connection, therefor. Also, the leads may be bent at the outslde suriaoe o! the tube, or enlarged or flattened at the outslde surface of the tube to hold the same in place.

Although I-have described particular lmprovements of my invention, lt will be understood that various modifications and adaptatlons may be made wlthout departlng Iroxn the scope of my inventlon.

I claim:-

1. A resislzance unlt cor'nprlsing an insulatlng tube, a reslstive element thereon, and a terminal to which said resistive element is electri'cally counected, said termlnal extending across the interior o! the tube substantially in a plane perpendioular to the axis 015 the tube and belng bent wlthin the tube to hold lt in place, and extending outwardly from the tube to !orxn an external terminal.

2. A reslstance unlt comprlslng an insulating taube, a reslstlve element thereon, and a terminal to which said resistlve element is electrlcally connected, said tube having a pair of openings extending from the outside o! the tube to the inside 015 the tube, and said terminal passlng through said openings and across the lnterlor 015 the tube substantially in a plane perpendlcular to the axls of the tube and being bent withln the tube to hold lt in place.

3. A reslstance unit comprlsing an insulating tube, a reslstlve element thereon, and a termlnal to whlch said resistlve element is electrlcally connected, said tube having a pair ot openings extending trom the outside 015 the tube to the lnside o! the tube, and said termlnal passlng through said openings and across the lnterlor 01 the tube substantially in a plane perpendlcular 1:0 the axis 01 the tube and being bent within the tube to hold it in place, and extending outwardly from the tube to forxn an external terminal.

4. A resistance unlt comprlsing an insulating tube, a resistive elemer'it thereon, and a termlnal to which said resistlve element is electrically counected, said tube having a pair o! dlametrically opposed openings extendlng from the outslde o! the tube to the inslde 015 the tube, and said terminal passlng through said openings and across the interlor of the tube and being bent wlthln the tube to hold it in place.

5. A resistance unlt comprlsing an insulating tube, a resistlve element thereon, and a termlnal to which said resistlve element ls electrically counected, said tube havlng a pair of openlngs extendlng from the outslde 013 the tube to the lnslde of the tube and located substantially in a plane perpendicular to the axis 01 the tube, and said tennlnal being in the forrn of a wire passlng through said openlngs and across the interlor of the tube and being bent wlthln the tube to hold lt In place. 6. A resistance unic, comprislng an insulating tube, a resistlve element thereon, and a terminal to whlch said reslstive element is electrically counected, said tube having a nah of dlametrlcally opposed openlngsextendlng from the outslde 01 the tube to the inside 01 the tube, and said terminal being In the Iorm 01 a wire passlng through said openings and across the interior of the tube and belng bent wlthln the tube to hold lt in place and extending outwardly (mm the tube to form an external connectlon.

7. A reslstance unlt comprlsing an lnsulatlng tube, a reslstlve element thereon, and a terminal to whlch said reslstlve element is electrically connected, said termlnal extendlng through two walls o! the taube and across the lnterlor ot the tube substantlally in a plane perpendlcular to the axis of the taube and belng bent to hold the saxne in flxed posltion on the tube.

8. A resistance unlt comprlsing an insulatlng taube, a reslstlve element thereon, and a termlnal to which said resistlve elementls electrlcally connected, said tube having a pair 015 openings extendlng from the outside 01 the tube to the inside 015 the tube and located substantially in a plane perpendlcular to the axls 01 the tube, and said terminal passing through said openlngs and across the Interim 01 the tube and belng bent to hold the same in fixed position on the tube.

9. A resistance unlt.doxhprislng an lnsulating tube, a resistive element thereon, and a termlnal to whlch said reslstlve element is electrically connected, said tube having a palr 01 openings extending Irom the outside 01 the tube to the inside of the tube and located substantially in a. plane perpendlcular to the axis o! the tube, and sald terminal passing through said openings and across the lnterlor 01 the tube and being bent to hold the same in flxed positlon on the tube and extending outwardly Irom the tube to Iorm an external termlnal.

FREDERIC H. BULIJNGER.