US2516572A - Solderless type terminal - Google Patents

Description

July 25, 1950 H. E. HELLER 2,516,572

SOLDERLESS TYPE TERMINAL Filed Oct. 31. 1947 2 Sheets-Sheet l July 25, 1950 H. E. HELLER 2,516,572

SOLDERLESS TYPE TERMINAL Filed Oct. 3l, 1947 2 Sheets-Sheet 2 m W6 H HW@ @4X7 www ,a E 56 58a 44a 55 56C I 4N iz-: /X

Patented .Fully 25, 1950 soLnERLEss 'rima 'rERmNAL Herbert E. Heller, West Allis, Wis., assigner to Cutler-Hammer, Ine., Milwaukee, Wis., a corporation of Delaware Application October 31, i947, Serial No. 783,331

d Claims.

-This invention relates to improvements in solderless type terminals and methods of making the same.

With respect to terminals of the aforementioned character there are a number of important requirements, certain or all of which have not been met by the solderless'type terminals now on the market. Among those requirements may be mentioned: (1) A suillcient length of rigidly supported screw thread must be available to prevent stripping thereof by the thread on the clamping screw upon tightening of the latter; (2) the 'stationary member of the terminal clamp must be stiff enough to withstand the torque which is applied when the screw is vtightened against the wire; (3) the wire-receiving space must be narrow, and of substantially theA same width as the diameter of the clamping screw, so as to properly conne the wire during and after the clamping operation; and (4) the construction must be such as to minimize the cost of material and labor for production of the finished article.

An object of the invention is to provide a solderless type terminal having all of the aforementioned desirable features.

Another object is to so construct and arrange the parts of the 'terminal as to provide for use thereof Where a limited space is available, particularly in respect of the permissible width of the terminal.

Another object is to provide a terminal of the aforementioned character having suitable means to aiord a separate additional electrical connection.

Another object is` to provide a novel method of assembling the parts of such a terminal and novel means for retaining said parts in assembled relation.

Another object is to provide novel means for removably attaching a stationary contact member to the terminal, after attachment of the latter to a suitable support.

Another object is to simplify the construction of and the manner of assembling the parts of terminals of the aforementioned character.

Another and more specinc object is to minimize the required thickness of the nut blank employed while alording the desired length of thread to be engaged by the clamping screw.

Other objects and advantages of the invention will hereinafter appear.

The accompanying drawings illustrate certain embodiments of the invention, which will now be described: it being understood that the embodiments illustrated are susceptible of modication in respect of certain structural details thereof without departing from the scope of the appended claims.

Inthe drawings,

Figure l illustrates (in double scale) one form` ture.

Fig. 3 is a top plan view of the terminal shown in Fig. 2, but with both the main terminal clamplng screw and the auxiliary wiring terminal screw omitted.

Fig. 4 is a top plan view of the current carrying part of the terminal,

Fig. 5 is an end elevational view of the punched and stamped sheet metal yoke member prior to assembly and attachment of the nut and the current carrying part thereto.

Fig. 6 is an outer end view of a modified form of terminal, wherein a previously drilled and tapped nut and the conducting member are assembled with respect to a yoke member, consisting of a tube section, by distortion or inward bending of the side walls of the latter; the screw when assembled with respect to the nut acting to positively prevent separation of the latter from the yoke.

Fig. 'l is a side elevational view of the device shown in Fig. 6; only a fragment of the conducting member being illustrated.

Fig. 8 is an end view, partly in elevation and partly in section, of a further modied form of terminal, wherein a relatively thinner nut blank is rigidly united with a tubular yoke, preparatory to drilling and tapping of said parts jointly to accommodate the shank of the clamping screw.

Fig. 9 is a view similar to Fig. 8, showing in dotted lines the manner in which the upper end wall of the yoke and the nut blank may be drilled and tapped after uniting of said parts, and

Fig. 10 is a side elevational view of the device shown in Figs. 8 and 9; only a fragment of the conducting member being illustrated.V

Referring to Figs. 1 to 5 of the drawings, the numeral il) designates a substantially U-shaped yoke, which is initially formed as shown in Fig. 5 from a punched and stamped blank of sheet metal. I prefer to employ for yoke l0 a metal, such as cold rolled steel. which is of great strength and toughness; it being understood by those skilled in this art that. there is no necessity for yoke I to be of unusually good electrically conducting character. The bottom wall or connecting portion II of yoke Ill is of prcdetrrmined width las shown in Fig. l), and portions l2 and I3 of the upstanding arms thereof are of a width corresponding thereto; said portions I2 and I3 being integrally connected vwith the relatively wider upper end portions I4 and I5 through the medium of the gradually widening portions IB and l1.

In the initial form of yoke III, as shown in Fig. 5, the arm portions I4 and I5 are provided with outward offsets, through the medium of the bends I8 and I8, respectively. The outwardly angled upper end portions of said arms are preferably each provided with a pair of inwardly extruded bosses; one boss of each pair being shown in Fig. 5, and respectively designated by numerals and 2|; said bosses being adapted Io facilitate a spotwelding operation, as hereinafter described. The external depressions required to form bosses 20 and 2l are designated by numerals 2i)a and 2I. The extreme upper ends of said arm portions I4 and I5 are bent inwardly at an angle, as shown at 22 and 23.

The conducting member of the terminal preferably consists of a strip of brass 24, of the shape and relative size illustrated in Figs. 1 to 4. Member 24 is preferably notched, when in flat or blank form, as indicated at 25 and 28 in Fig. 4. to provide a relatively narrower or neck portion 21, the width of which preferably closely corresponds `with the length of the aforementioned connecting portion II of yoke I4.

The brass member 24 is provided with a flat rear end portion 28 having a circular opening 29 formed therein, for a purpose to be described; an integral upwardly offset portion 30 having a tapped opening 3| formed therein, for a. purpose to be described; and the forward end portion of member 24 is further bent to extend upwardly. then forwardly flatwise, -and then downwardly. as indicated by the portions 32, 33 and 34 in Fig. l, to a sort of inverted U-shape. As best illustrated in Figs. 2 and 4, the upper surface of the flat portion 33 is provided with a pair of transversely extending raised or extruded portions 35 and 38, in a predetermined spaced relationship to each other, and each comprising a1- -ternate grooves and ridges extending longitudinally of fiat portion 21, as best illustrated in Fig. 2. As an incident to the bends between portions 32 and 33 and portions 33 and 34, the lower ends of the spaced shoulders 31, 38 and 38, 40 are angled inwardly toward each other to afford a spacing thereof only slightly greater than the width of the portions I2 and I3 of the arms of yoke I 0.

In assembling the parts of the terminal, the conducting member may be inserted downwardly into yoke I0 (Fig. 5) in a manner to provide for accommodation of the arm portions I2 and I3 within notches 25 and 28. Thereafter a rectangular steel block 4I, preferably of square peripheral contour, is freely insertable, either downwardly or laterally, between the portions I4 and I5 of the yoke arms; said block being adapted to rest temporarily upon the inner surfaces of the aforementioned bends I8'and I8. The arms of the yoke III-are then pressed inwardly toward each other, until the inner ends of the bosses 20 and 2I engage one pair of opposite parallel sides of block 4I; the pressure upon said arms being maintained during application of a suitable welding current, which results in fusion of the bosses 20 and 2| to effect spot-welding ol said arms to'block 4I, as indicated by the relative positions of the yoke arms in Fig. 2. The extreme upper ends 22 and 23 ol the arms of yoke I0'will then overlap to some extent the upper surface of block 4I.

Thereafter the relatively narrow portions I2 and I3 are bent inwardly at the points 42 and 43 (Fig. 2) to overlie a portion of the upper surface of the reduced or neck portion 2l of the current carrying member 24, to rigidly and permanently secure the latter and yoke I8 in fixed relationship to each other.

A screw or bolt 44, preferably having a kerfed head as shown, has its shank 441 in threaded engagement with a tapped'opening 4I formed in the block 4I. In practice I prefer to provide block 4I with a drilledV and tapped opening after said parts are united by welding, as aforedescribed. As best illustrated in Fig. 2, the diameter of screw shank 44 is only slightly less than the distance between the portions of the yoke arms extending from the lower surface of nut 4I to the upper surface of member 24, to insure proper clamping of a conductor i not shown) between the lower end of screw shank 44n and member 24. I prefer to provide screw 44 with a con'- vex lower end 44h, although said screw end may be made dat, conical, or of other shape if desired.

As will-be apparent from consideration of Figs. 1 and 2, the screw, when tightened against .an inserted wire or conductor, will cause the conductor to be bent or distorted between the spaced portions 35 and 36 on member 24, and the wire will be pressed into the desired degree of interlocking engagement with member 24 to insure against accidental displacement or loosening of the wire.

While I have shown the screw 44 as of the kerfed type, to provide for operation thereof by a screw driver, it will be understood that the head thereof may be of polygonal contour (as illustrated) to provide for alternative operation thereof by a wrench of any suitable or wellknown form.

The downwardly bent outer end portion 34 of member 24 is preferably provided with a tapped opening @I4a to accommodate the threaded shank 45a of a. screw or bolt the hexagonal head of which is shown at 45 in Fig. 1, to provide for operation thereof by a wrench. As shown, the head 45 may also be provided with a kerf to permit operation of said screw by means of a screw driver. The circuit wire or wires (not shown) may be clamped to the outer surface of portion 34 in the usual manner, a flat washer 46 and a lock washer 41 being preferably interposed between the conductor and the screw head 45.

As shown in Fig. 1, the assembled terminal parts thus far described are adapted to be positioned within a groove 48 of rectangular form in transverse cross section, and of only slightly greater width than member 24, formed upon the upper surface of an insulating base, a fragment of which is shown at 48. Base 48 is preferably provided with an opening or passage 4I!b to accommodate the tubular shank of a headed rivet 50 which passes downwardly through the aforementioned opening 29 in member 24 and through a suitable metal washer 5I, and is upset over the lower surface of the latter, as indicated at 50a.

After rigid and permanent attachment of the solderless terminal to base 48 as just described, a stationary switch contact assembly A(comprisaforementioned terminal screw 235.

ing a punched plate t2 of metal of goed electrical conductivity, such as copper, brass or bronze, and having a contact tip 53 oi silver or a silver base material rigidly and permanently attached thereto) is removably attached to the soiderless terminal, as by means of a screw 5d whose threaded shank penetrates a clearance opening provided in plate 52 and takes into the aforementioned tapped'opening 3| (Figs. 3 and 4) in member 2Q; a split lock washer 55 being preferably interposed between the head of screw 54 and the plate 52. Base 48 is shown as recessed at ith and 48d to accommodate the shanks of screws et and H5.

As will be apparent from consideration oi' Fig. 2, the extreme upper end portions 22 and 23 of the arms of yoke I might be bent or wiped inwardly over the upper surface of nut il, after the aforementioned spot-welding operation, if considered. desirable for any reason, such as improving the appearance of the device.

At 56 in Fig. l l have shown one end of a movable or bridging contactor having a contact tip 51 thereon for cooperation with the aforementioned contact tip 53.

As best illustrated in Fig. 1, the lower surface of member 24 is pressed upwardly, as shown in dotted lines at 35 and 36, as an incident to formation of the aforementioned raised or extruded portions 35 and 36. Although I prefer to form the member 24 of brass, it is to be understood that said member might be composed of another metal of good electrical conductivity, such as copper or bronze.

Also, as shown in Fig. 1, the lat bottom wall of recess 48d is of sufilcient width to accommodate and afford a seat for the straight lower edge 34" of portion 34 of conducting member 24. rlhe seating of edge 34b against the aforementioned portion of base i8 assists in preventing distortion or displacement of any portion of conducting member 24 as an incident to tightening of the l As will be understood, in a given switch mechanism the number of screws Q employed will ordinarily depend upon the number of soiderless connectors required; said screws d5 affording the internal connections for the switch parts.

in the modied form of soiderless, or clamp type, terminal shown in Figs. 6 and '7 certain of the parts may be identical with those shown in Figs. l to 5, and the same have been given corresponding numerals of reference. Thus, in Figs. 6 and 7, the screw d@ and metal conductor member 2d may be identical with the corresponding parts aforedescribed. However, the yoke inember 58 in this form of my invention is shown as consisting of a section or length of cold rolled steel tubing (preferably seamless). The upper end portion of yoke 53 may be initially formed with the fiat upper end wall 58B, the straight side wall portions 53D and 58C, and the inwardlybent or odset portions dtd and tte, which form shoulders to prevent downward displacement of a nut di (which preferably corresponds in shape and size with the block di of Fig. 2, but is provided with a drilled and tapped opening @HY prior to assembly thereof with respect to yoke 58). rlhus, the nut dix may be inserted or slid laterally into the upper end portion of yoke 58, the upper end wall 58a of which is provided with a circular opening 58 of only slightly greater diameter than the diameter of the shank of screw M. Upon threading of screw d@ into the tapped opening diy in nut SIX the peripheral wall of opening diy will cooperate with said screw shank to prevent any substantial degree of lateral displacement of nut 4 i with respect to yoke 68.

The metal conductor member 24 of Figs. 6 and 'I is inserted within yoke 58 and seated against the lower end wall of the latter, whereupon the lower end portions of the side walls of said yoke are pressed, rolled or otherwise offset inwardly. as shown at 588 and 58h, to overlie and engage the upper surface of member 24, the side edges of which are notched as aforedescribed, whereby member 24 and yoke 58 are rigidly and permanently united.

lf desired, the upper end portion of yoke 58 may be spot welded to nut lx, in Figs. 6 and 7; although for practical purposes such permanent attachment of these partsin this form of my invention is not necessary; elimination of such spot welding operation effecting a substantial saving in the cost of assembly of said parts.

ln the further modified form of my invention shown in Figs. 8, 9 and 10 the clamping screw it may be identical with the corresponding part in the other iigures aforedescribed; although, if desired, the screw employed in Figs. 8, -9 and 10 might be shortened to a degree corresponding to the thickness of the upper end wall 59* of the yoke 59, thus correspondingly reducing the over' all height of the complete unit. The yoke 59 (like the yoke 58 of Figs. 6 and '1) preferably consists of a suitable length' of cold rolled seamless steel tubing; the length of said section preferably corresponding to the length of the respec tive sides of the* square steel block 60 here employed. Block 60, as shown, is substantially thinner than the block 4| (Fig. 2) or the nut il! (Fig. 6), and is rigidly and permanently attached to the upper end wall 59 of vyoke 59, as by spot welding at a plurality of points, as indicated at 59D and 59 in Fig. 9. After uniting block 60 to yoke 59 the upper end wall 59 and block 60 are provided with a drilled and tapped openingl common thereto, as indicated by the inner and outerpairs of dotted lines 6| and $2 in Fig. 9. In this manner a thread of suillcient length and strength is provided for cooperative engagement by the threaded shank of screw B4.

The punched and stamped metal member 63 of goodelectrical conductivity is substantially like the member 24 aforedescribed, but diiers therefrom only in respect of the increased length of the slots on opposite sides thereof (one of which is shown in dotted lines at 64 in Fig. 10) to accommodate the length of the tube section forming the yoke 59. Member 63 is inserted into yoke 59 and seated against the lower end wall thereof, whereupon the side walls 59d and 58 are bent or pressed inwardly at 59f`and 598 to overlie and engage the upper surface of member S3, whereby the latter is rigidly and permanently attached to yoke t9, as aforedescribed. The other portions of member 63 may be of the same shape and size as the corresponding portions of the aforedescribed member 2t.

As shown in Figs. 8 and 9 the side walls of yoke 59 may be bent or pressed inwardly at 59h and 591 either before or after insertion of block into or permanent attachment thereof to yoke 5t by spot welding as aforedescribed; thus not only rigidifying yoke 59, but also insuring formation of a conductor wire receiving opening in yoke 59 which is only slightly greater than the diameter of the shank of screw 44, for the purpose aforementioned.

I claim:

1. A solderiess type terminal clamp comprising a U-shaped sheet metal yoke, a metal conductor member positioned within said yoke at the lower end thereof, and a nut and bolt carried between the upstanding arms of said yoke, said nut forming the upper wall of said clamp, and said upstanding arms of said yoke being deformed about said conductor member and said nut to afford retention of said parts in assembled relation and simultaneously to alford spacing of said arms just suilicient to provide clearance therebetween for said bolt when threaded downwardly to effect clamping of a conductor wire between said bolt and said conductor member.

2. A solderless type terminal clamp comprising a. U-shapcd metal yoke, a metal conductor member positioned within said yoke at the lower end thereof and havingr an interlocking engagement with the upstanding arms of said yoke, a nut carried between said arms and forming the upper wall of said clamp, a bolt threaded into said nut, the intermediate portions of said arms being bent inwardly to overlie said conductor and to underlie said nut to retain those parts in assembled relation and simultaneously to afford spacing of said arms just suflicient to provide clearance therebetween for said bolt when threaded downwardly to eiect clamping of a conductor wire between said bolt and said conductor member, and the upper ends of said arms being bent inwardly to prevent upward displacement oi said nut.

3. A solderless type terminal clamp comprising a U-shaped metal yoke, a metal conductor member positioned within said yoke at the lower end thereof, said conductor member having rectangular notches formed in opposite side edges thereof to interlock with the upstanding arms of said yoke, a nut carried between said arms and spot welded thereto, said nut forming the upper wall of said clamp and having a bolt threaded therethrough, the intermediate portions of said arms being bent inwardly to ovcrlie said conductor member and to underlie said nut to retain those parts in spaced relation and simultaneously affording spacing of said arms just sufficient to provide clearance for said holt when threaded downwardly `to eil'ect clamping of a conductor wire between said bolt and said conductor mr-m ber.

4. A solderlcss type terminal clamp comprising a. U-Shaped metal yoke, a metal conductor member positioned within said yoke at the lower end thereof, said conductor member haviiw rectanguiar notches formed in opposite side edges thereof to interlock with the upstandini', arms of said yoke, a nut carried between said arms and spot welded thereto, said nut forming the upper wail ofsaid clamp and having a bolt threadid therethrough, the intermediate portions of said arms being bent inwardly to overlie said conductor member and to underlie said nul, to retain time parts in spaced relation and simultaneously alfording spacing of said arms just suilieient to provide clearance for said holt when threaded downwardly to eilect clamping oi a conductor wire against said conductor member, the latifr having transverse ridges to eid in clamping said wire securely and additionally having a downwardly bent portion having :i screw threaded therethrough for attachment of additional circuit wires.

HERBERT E. HELLER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,109,962 Chadwick Sept. 8, 1914 2,013,013 Van Valkenburg Sept. 3, 1935 2,173,206 Landmeicr Sept. 19, 1939 2,193,202 Millermastcr Mar. 12, 1940 2,232,602 Grace Feb. 18, 1941 2,276,736 Olson Mar. 17, 1942 2,285,928 Jensen June 9, 1942 2,304,972 Van Valkenburg Oct. 15, 1942 2,371,446 Jensen Mar. 13, 1945 FOREIGN PATENTS Number Country Date 542,065 Great Britain Dec. 23, 194i

Images