US3032865A

US3032865A - Assembly device for bus bars

Info

Publication number: US3032865A
Application number: US816919A
Authority: US
Inventors: George H Hart
Original assignee: Hart Manufacturing Co
Current assignee: Hart Manufacturing Co
Priority date: 1959-05-29
Filing date: 1959-05-29
Publication date: 1962-05-08
Anticipated expiration: 1979-05-08

Description

G- H. HART ASSEMBLY DEVICE FOR BUS BARS May 8, 1962 Filed May 29, 1959 3 Sheets-Sheet 1 54 FIG. I 5@ I 28 with INVENTOR. GEOPGE H. HA R T ATTORNE Y5 May 8, 1962 G. HART ASSEMBLY DEVICE FOR BUS BARS 3 Sheets-Sheet 2 Filed May 29, 1959 FIG. 3

FIG. 4

INVENTOR. GEORGE H. HA R 7' ATTORNEYS May 8, 1962 G. H. HART I 3,032,865

ASSEMBLY DEVICE FOR BUS BARS Filed May 29, 1959 5 Sheets-Sheet 3 n I# I I/ I 42 /Z M a: /4

INVENTOR. FIG. 9 w m A? GEORGE H. HART A TTOPNE Y5 United States Patent 3,032,865 ASSEMBLY DEVICE FOR BUS BARS George H. Hart, West Hartford, Conn., assignor to The Hart Manufacturing Company, Hartford, Conn., a corporation of Connecticut Filed May 29, 1959, Ser. No. 816,919 13 Claims. (Cl. 29203) This invention relates to a manually operable assembly device for the simultaneous attachment of a plurality of electrical units such as switches to an improved type of bus bar having restricted socket openings.

A primary object is to provide an assembly device for rapid attachment of electrical units having elongate contacts to bus bars of the type having integral center and outer socket forming strips with portions of the outer strips restricting the socket opening to the extent that they must be distorted by pivotal movement of a bus bar about a contact when partially inserted in the socket to enlarge the socket opening before the contact can be forced completely therethrough. The socket forming strips are termed jaws herein.

1 A further object is to provide a device for positioning a plurality of contact carrying electrical units aligned in relation to one or to a plurality of bus bars and for controlling or manipulating the bus bars through paths of movement in respect to the contacts during a unitary manually controlled operation, in a manner rapidly and effectively to accomplish the clamped engagement of the bars to the contacts of the units.

A still further object is to provide an assembly device which is simple to operate; requires a minimum of operator training for reset from one work pattern to another; is self-contained and portable in that it requires no auxiliary equipment and may be moved by one person to various Work stationsis sufliciently rugged to withstand rough handling; insures accurate performance and trouble-free service life; and substantially decreases assembly time and costs.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth and the scope of the application of which will be indicated in the appended claims.

In the drawings:

FIG. 1 is a fragmentary top view of an assembly device constructed in accordance with the invention.

FIG. 2 is a fragmentary end view of the device of FIG. 1.

FIG. 3 is an enlarged fragmentary view, partly in elevation and partly in section, taken along line 3-3 of FIG. 1.

FIG. 4 is an enlarged fragmentary top view of the device of FIG. 1. 1

FIG. 5 is an enlarged cross-sectional view taken along 5-- 5 of FIG. '1.

FIG. 6 is an enlarged fragmentary view similar to FIG. 5 but with some of the parts omitted.

' FIG. 7 is an enlarged fragmentary cross-sectional view substantially along the line 77 of FIG. 1, but showing dotted an electrical unit and bus bars in a position of final assembly.

FIG. 8 is a top plan view of a bus bar of the type with which this invention is concerned; and

FIG. 9 shows in side elevation a bus bar fragment of FIG. 8.

The improved bus bar shown in FIGS. 8 and 9 is of the type described and claimed in a pending U.S. application, Serial No. 697,683 filed November 20, 1957, now

ice

Patent No. 2,981,926. Such a bus bar, generically designated 10, is fabricated from metal stock 11 which may be a copper strip cut and formed in areas spaced along the strip to providesets of jaws to receive and clamp fiat elongate contacts transversely of the bar. Each set of jaws is formed by two longitudinal slits made to define a center strip 12 separated from marginal strips 14 on either side thereof and laterally offset from the major plane of the bar to form a pair of lower jaws as viewed in FIG. 9. The center strip has a mid-portion laterally offset in the opposite direction to form a top jaw, the three jaws thus formed defining a contact receiving socket transversely of the bar. The mid-portion of each strip 14 is bent diagonally toward the strip margin at 16, FIG. 8, to form a lip, the outer margin of which is in substantial alignment with the main plane of the strip stock.

The jaws thus formed represent a substantial improvement over conventional bus bar jaws, but because the liplike portions 16 restrict passage of a contact between the outer and center jaws, the contact must first be inserted between one of the outer jaws and the center jaw, with the end thereof abutting the inner margin of the olfset outer jaw, in which position the bus bar may be pivoted against the contact to spread the first two mentioned jaws and thus open the socket to allow projection of the contact past the second outer jaw and through the socket. While the clamping forces exerted by such jaws against a contact projected therethrough greatly exceed comparable forces of conventional jaws, certain difiiculties are encountered in assembly of electrical units to such bars and manual assembly has proved a difficult and tedious operation. The present invention permits a plurality of electrical units arranged in a pre-set pattern and each provided with contacts, rapidly to be attached to a plurality of bus bars having the above-described improved jaws, by a unitary manually controlled operation easily accomplished by persons of limited skill.

As best shown in FIGS. 1 and 2, a press type assembly device includes a base 20 having a pair of

upright posts

22 and 24 at the back thereof as viewed in FIG. 1. The posts are provided with aligned bearings through which shafts 25 project, the shafts being fixed to the ends of a lower offset portion 26 of a pressure plate 28, to mount the plate for manual pivoting by handle 30, from the vertical heavy line position of FIG. 2 to the horizontal dotted line position shown. Compression springs 32 encircle extended portions of each shaft 25, laterally of the bearings, with one end of each spring anchored to the bearing and to the opposite end to the shaft to bias the pressure plate vertically against the counter-bias of bus bar positioning plates carried by each of the positioning blocks, in spring urged engagement with the lower offset portion of the pressure plate, as more fully described below.

Base 20 is provided longitudinally with a pair of inverted

T slots

34 and 36 and an intermediate guy lug slot 38 to receive, respectively, the heads of clamp bolts 39 and guy lugs such as 41 carried by a plurality of electrical unit and bus bar positioning blocks, such as

blocks

40 and 42, and bus bar centering blocks such as 44 and 46, both type blocks being adjustably positionable and clamped in spaced relation longitudinally of the base as later described. Pressure plate 28 is similarly provided with

T slots

48, 50 and a guy lug slot 52 for positioning a plurality of

press blocks

54, 56 for pressure engagement with electrical units held by the positioning blocks during operation of the device.

The fragmentary top view of FIG. 1 shows the various fixtures set up on the left side of the base for assembly of two electrical devices, such as switches, to three spaced bus bars. The right side of the base may have fixtures set up in an identical manner for like assembly of additional electrical units to another separate set of bus bars during the same operation, hence the invention can be fully described by reference only to the apparatus associated with the left side of the base. Alternately, the device may be set up for assembly of four or more electrical units to a single set of longer bus bars; for example, of a length to extend longitudinally over a major portion of the base.

Referring to FIG. 1, it will be noted that

positioning blocks

49 and 42 are not of identical construction, but they both receive and position, in transverse parallel grooves Provided therein, a plurality of bus bars, three bars being simultaneously attached to electrical units by the device shown. The bus bar sockets are accurately positioned transversely of the blocks by fingers 45 extending inwardly of centering blocks 44 and 46 to center the strip-like bars therebetween. The first two bus bars are loosely received in an upright position in the rear transverse grooves (those nearest the pressure plate), while manual positioning of a third or front bus bar in its groove actuates control mechanism described below automatically to position and clamp all three bars inclined in respect to the block grooves with their sockets positioned to receive the tips of the unit contacts therein. Each positioning block is upwardly open and contoured by

removable side plates

35, 37 to receive a contact carrying electrical unit 43 and guide it in a manner to first position its contacts partially extended into the bus bar sockets, and to later guide it as its contacts are urged completely through the sockets.

With the units in the positioning blocks as shown in FIG. 6, and the contacts thereof between the upper and center jaws of the bus bars, the bars are simultaneously pivoted against the back vertical walls of the block grooves by bus bar control plates as the pressure plate is lowered, the bar jaws being spread by the partially inserted contacts, around which the bars must pivot as they are swung to the vertical. With continued swing of the pressure plate, the units 43 are forced downwardly by

press blocks

54, 56 carried by the pressure plate, with their contacts being thus urged under pressure through the bus bar jaws as shown in FIG. 7.

A positioning block of the type numbered 42 is shown in FIGS. 3 and 4, with FIG. 5 showing the type numbered 40. Each block has the same body 49 with lateral shoulders 51, bored to receive Allen screws 39 threadedly engaging T-nuts 39a to permit adjustability from above the base by an Allen wrench. Each upwardly open block chamber has a bottom wall transversely channeled to define lands and grooves, as shown in FIGS. 1 and 6, the three

parallel grooves

53, 55, 57 being of equal depth. A deeper groove 58 receives dowels 66, extending downwardly from the units 43 as shown in FIGS. 6 and 7. The grooves of the several blocks are in alignment longitudinally of the base to receive the bus bars and dowels, respectively. Each block has thus formed therein spaced pairs of

lands

72 and 74, one at each side of the block, a pair of rear shoulders 75, and a pair of small forward lands 77, with

grooves

53, 55, and 57 therebetween. While the blocks are identical in the above respect, they differ in a manner described below as to bus bar control elements slidably mounted transversely of the lands and grooves.

As shown in FIG. 1, block 40 has a cam plate 63, slidably mounted transversely of the bar grooves and spaced inwardly of the left side of the block. Block 42 has an identical plate 69 spaced inwardly of its right side. Each plate, as shown in FIG. 7, is biased back toward the pressure plate by a spring 71, the plates having upwardly open grooves shaped to register with the block grooves when the plate is held in a forward position against the pressure of its spring 71 by the pressure plate when vertical, as shown in FIGS. 2 and 5, the plates being moved to the FIG. 7 position by' springs 71 as the pressure plate is swung toward the horizontal.

Block 42 carries a bus bar canting plate 70 slidably mounted laterally of cam plate 69 and latched to the block when positioned as shown in FIG. 3 by a stop 74 carried by a pin 78, slidable vertically of the front bar groove and urged upwardly by a coil spring 79. A pawl 73 pivots about a pin 73a, fixed to the block and has a loose pin connection 73b to cam plate 69. The top of plate 70 is provided with lands and grooves for registry with corresponding lands and grooves of both the block and the cam plate when in the latched position of FIG. 3, but the left walls of the grooves are diagonally cut as at 76. Plate 70 is biased to the right as viewed in FIG. 3, by leaf spring 81, but since latched to the block by stop 74, the action of that spring is arrested until pin 78 is depressed to a position flush with the base of the block groove to move stop 74 downwardly and clear of a latching shoulder 80 defined by a notch 83 in the canting plate 70. When unlatched, plate 70 moves to the right sufiiciently to tilt the bus bar as described below, and is returned to the FIG. 3 position as cam plate 69 is recarnrned to the left, by pawl tooth 73c which engages a shoulder 70a in plate 70 to connect plate 70 to cam plate 69 for return of plate 70 to the latched position.

Block 40 has a somewhat different bus bar control plate 82 slidably mounted along its left side laterally of cam plate 68 and biased to the left by spring 84 as shown in FIG. 5. Plate 82 also has upward lands and grooves registerable with those of the block when moved to the right from the position shown against the bias of spring 84. The lands of plate 82 form laterally projecting hook portions 86 and its grooves are defined by vertical walls at the left and diagonal Walls at the right, as shown in FIG. 5, whereas the corresponding grooves of plate 70 have vertical walls at the right and horizontal walls at the left, as shown in FIG. 3. There is no interlinking connection between plate 68 and plate 82 of block 40. Each block is provided with a pair of resiliently mounted rests 96 and 89 which serve both to properly support the electrical units 43 in the block chambers with their contact tips disposed as shown in FIG. 6, and as knockout blocks to raise the units and attached bars as the final step in the assembly operation. Rests 96, 89 are horizontally supported by

slidable pins

91 and 93 having

stops

95, 97 and biased upwardly, respectively, by coil springs 99 and 101.

Detailed operation of the device is as follows:

With pressure plate 28 in the fully vertical position of FIG. 2, an adjustable limiting stop 88 engages a stop post 90, with a cam strip 92, marginally of the inner surface of offset plate portion 26 positioned to hold

cam plates

68 and 69 forced against their spring 71 with the cam plates depressed and the grooves thereof in registry with the bar grooves. When so positioned, plate 70 is latched to block 42, as shown in FIG. 3, and plate 82 is biased by spring 84 into the FIG. 5 position with the inclined groove walls extending partially into the block grooves. The device is now ready to receive the bus bar, a strip at a time, the manual loading operation starting from the back groove, the bus bars being placed in the grooves, with the center bar jaws toward the operator. The jaws defining the bar sockets are properly positioned inthe blocks as they are dropped into the slots between the centering fingers 45. The first two bars are loosely received and may assume either a vertical or a diagonal position, but as the third bar is dropped into the front slots of the blocks, the operator depresses it against pin 78 to unlatch plate '70 which springs rearwardly (toward the pressure plate) under the urge of spring 81 with the inclined groove walls thereof forcing the bars into clamped engagement with the inclined walls of plate 82 and the upper bar margins recessed under the finger-like. hooks 86 firmly to hold the bars in the grooves, as positioned as shown dotted in FIG. 6. v

The electrical units 43 are then dropped, contacts down, into the block channels in which they are loosely received but properly guided to cause their

contacts

83, 85, and 87 to project between the upper and central strip of each bar jaw, with units supported, when so positioned, on rests 96, 89. The operator then swings pressure plate downwardly by handle 30 toward the dotted horizontal position of FIG. 2. During early stages of this final operation, cam strip 92 swings outwardly of

cam plates

68 and 69 to allow biasing springs 71 to move their plates toward the vertical rear groove Walls thereof and pivot the bars from the inclined FIG. 6 to the vertical FIG. 7 position with the bus bars held firmly clamped vertically in the block grooves between the vertical groove Walls 65, 65a and 65b and the lower vertical walls of the block grooves. As the bus bars are thus pivoted simultaneously with the outward swing of the cam strip 92, plate 82 is pushed back clear of the grooves against the bias of its leaf spring 84 by the substantially stronger counter-bias of coil spring 71 to remove the inclined bar positioning Walls of plate 82 from the block grooves, thus permitting vertical bar clamping as above described.

As the pressure plate continues its swing to the horizontal, press blocks 54, 56 engage upper surfaces of the units 43, and force them downwardly of the blocks, depressing rests 89, 96 and forcing

contacts

83, 85, 87 completely through the bus bar jaws, as shown in FIG. 7, to complete the attachment of the bars to the units. As the pressure bar is swung back to vertical, and the press blocks move out of engagement with the units, rests 89, 96 push the units upwardly under urge of their biasing springs, and the attached bus bars are forced out of the grooves to facilitate removal of the unitary assembly. As the pressure plate approaches vertical, cam strip 92 resets the device for the next cycle of operation by forcing

cam plates

68 and 69 forwardly to again register the plate grooves with the block grooves, such depression of cam 69 causing pawl 73 thereof to engage and move plate 70 forwardly for re-latching as shown in FIG. 3.

While only one of each type of bar positioning block is shown and described above, two or more of each type block are often used for simultaneous attachment of four or more electrical units to bus bars. When three units are to be attached, it is preferable to set up the device with a type 42 block spaced on opposite sides of a type 40 block. To facilitate set-up for any desired pattern of assembly, a measuring rule 104 is fixed to the top of base 28 along the front margin thereof, and an identical rule 186 is mounted, With its scale in longitudinal registry therewith to the front surface of the pressure plate adjacent the top of the press blocks, as best shown in FIG. 6. Each press block is provided with .a scale pointer 108 overlying rule 106 and each front wall of a positioning block carries a rule line, as indicated by groove 110, FIG. 4. Corresponding scale settings of the pointers and marking lines accurately establish vertical registry between each positioning block and its co-operating press block.

As will be apparent to persons skilled in the art, various modifications and adaptations of the structure above described will become readily apparent without departure from the spirit and scope of the invention, the scope of which is defined'in the appended claims.

I claim:

I. A press-like assembly fixture for attaching electrical units having strip-like contacts to an elongate bus bar having transverse sockets formed by jaws and in which socket restricting portions extend longitudinally thereof, said fixture comprising a base, a pressure plate mounted for movement in respect to the base, positioning means supported on said base for positioning a bus bar lengthwise thereabove, clamping means supported on the base and transversely oriented with respect thereto and operatively associated with said positioning means for clamping said bus bar in a transversely inclined position relative to said base, means on the base for positioning a plurality of electrical units above the bus bar with tip portions of said contacts extending vertically relative to said base into said sockets and underlying said restricting portions, pivoting means supported adjacent the base and operatively associated with said bus bar positioning means and said clamping means and connecting said pressure plate for actuation thereby to pivot the bus bar about the contacts and into a position of alignment therewith, whereby said restricting portions are forced laterally outwardly of said sockets, and means on said pressure plate to force said contacts through the bus bar sockets.

2. An assembly device for forcing elongate contacts of electrical units through bus bar sockets formed transversely of the bar by longitudinally extending jaws having socket restricting portions which must be forced laterally by pivotal manipulation of the contacts to permit contact extension therethrough, said device comprising longitudinally extending support means for disposing a plurality of bus bars lengthwise on edge and in parallel spaced relation, means mounted adjacent said support means for positioning a pluarlity of contact carrying units with their contacts overlying the sockets formed in the supported bus bars, means on said support means and transversely oriented with respect thereto for positioning and clamping said bars in a transversely inclined position relative to said support means with the bar jaws thereof positioned to allow the contact tips to enter the sockets and underlie said restricting portions, pivoting means mounted adjacent said support means for spreading the bar jaws by pivoting the bars from said inclined position about said contact tips into alignment with the contacts, whereby said restricting portions are forced laterally outwardly of the socket, means on said support means for clamping said bars in said position, and forcing means mounted adjacent said support means for forcing the contacts of the units through the spread bar jaws.

3. The device of claim 2 wherein said support means comprises positioning blocks provided with longitudinally extending bus bar receiving grooves, and said means for positioning and clamping said bars comprising a bus bar control plate slidably mounted on each block for transverse movement relative to the block grooves, each plate being provided with grooves registrable with the block grooves, and with cam means connecting said forcing means and said control plate and operable by said forcing means for moving said control plate from a position of registry of the grooves thereof with the block grooves to a position of non-registry therebetween to clamp the bus bar in the block grooves.

4-. In a device for attaching an electrical unit having an elongate contact to a bus bar having a transversely positioned socket defined by jaws and in which a longitudinally extending socket restricting portion must be forced laterally outwardly to enable the socket to receive the contact, support means for holding the bar along its length with the socket positioned to receive the contact, means on said support means and operable therewith to position the unit with the contact thereof disposed partially within the socket and underlying said restricting portion, means on said support means for pivoting the bar about the contact from the contact receiving position to force the socket restricting portion laterally outwardly of the socket and thereby align the socket with the contact, and means mounted adjacent said support means for urging said contact into said spread socket.

5. In a device of the character described, an electrical unit and bus bar positioning block comprising a base provided with an upwardly open chamber for receiving the electrical unit and a groove extending through the block for supporting a bus bar below the chamber a pair of centering blocks, each centering block located laterally and on opposite sides of said positioning block and containing means for centering a bus bar extending therebetween and supported by said groove, a cam plate slidably mounted in said block for transverse movement relative to said block groove, said plate having a groove registrable with the block groove, a positioning plate slidably mounted on said block for transverse movement relative to said block groove and having a groove registrable with the block groove and including an inclined wall, resilient means connecting said cam plate and said block and biasing said cam plate toward a direction of non-registry of its groove with the block groove, and resilient means connecting said positioning plate and said block and biasing said positioning plate in the opposite direction for non-registry of its groove with the block groove with the inclined wall thereof partially restricting the block groove.

6. In a device for attaching elongate bus bars to electrical units having strip-like contacts, a longitudinally extending base, a plurality of blocks for positioning the elongated bus bars and electrical units and mounted in aligned longitudinal spaced relation on said base, a longitudinally extending pressure plate pivotally mounted on said base, a plurality of press blocks mounted in aligned longitudinal spaced relation on said pressure plate and in transverse alignment with said positioning blocks and movable by pivotal movement of said pressure plate into registry with said blocks, each positioning block being provided with parallel transversely spaced grooves in longitudinal alignment with corresponding grooves of the other blocks along the base and dimensioned for supporting the bus bars on edge along their length, each said block being formed with an upwardly open vertical chamber above the grooves for the reception of electrical units, means on said base and connecting said pressure plate and associated with each block and operable in response to pivoting of said pressure plate to a position of non-registry between said positioning blocks and press blocks to move and clamp said bus bars along their length to a transversely inclined position in respect to the vertical chambers, and further means on said base and connecting said pressure plate and associated with each block and operable in response to the pivoting of said pressure plate from said position of non-registry toward a position of registry between said positioning blocks and press blocks to move and clamp the bus bars along their length into transverse vertical alignment with said block chambers.

7. In a device for attaching bus bars to electrical units, a base, a plurality of positioning blocks aligned on said base, each block provided with an upwardly open chan1- her for the reception of an electrical unit, each block chamber having at the bottom thereof a plurality of spaced parallel grooves for the reception of bus bars, inclined wall means on the base and associated with said blocks and extending into said grooves for positioning and clamping bus bars in an inclined position relative to said upwardly open chamber, vertical wall means on the base and associated with said blocks for subsequently positioning and clamping the bus bars vertically relative to said chamber, a pressure member mounted on said base to pivot from a position vertically thereof to a horizontal position adjacent said positioning blocks and above said chamber, and cam means cooperatively connected between said pressure member and said inclined wall means and said vertical wall means for actuating said inclined wall means by vertical positioning of said pressure member and for actuating said vertical wall means in response to the pivoting of said pressure member from the vertical toward the horizontal position.

8. In a device for attaching the strip-like contact of an electrical unit to a bus bar having a transverse socket formed therein and defined by a center jaw and a pair of marginal jaws laterally olliset from the center jaw, longitudinally extending support means for supporting the elongated bus bar on edge along its length, means on said support means and transversely oriented with respect thereto for holding the bar in a transversely inclined position relative to said support, means on said support means for positioning the electrical unit above said bar with the contact extending downward between and in contact with one of the marginal jaws and the center jaw of the socket, pressure means mounted adjacent said support means and movable into engagement with the electrical unit, and pivoting means connecting said pressure means and said bus bars and operable by movement of the pressure means to pivot said bars about said contacts from the transversely inclined position to a position of transverse alignment with said downwardly extending contact where by said jaws are spread and said contact may be urged between the center and both marginal jaws by force exerted on said unit by said pressure means.

9. In a fixture for attaching electrical units having strip-like contacts to bus bars provided with transverse sockets, a longitudinally extending base, a member pivotably attached to said base, a plurality of positioning blocks mounted on said base, each said block being provided with a longitudinally extending groove leading upwardly into an open chamber, said blocks being positioned on the base to align said grooves to receive a bus bar positioned to extend between the blocks, the open chamber of each block being adapted to receive an elec trical unit with its contact extending downwardly within the transverse sockets of the bus bar, means on the base and associated with said blocks for positioning said bar with the transverse sockets inclined upwardly in the grooves, forcing means on the base for forcing said bars from the socket inclined position to position the sockets vertically, actuating means connecting said member and said forcing means for actuating said forcing means in response to the pivoting of said member, means on said member for forcing the electrical unit toward said groove and said contact through a bar socket when said socket is vertically positioned, and knockout means in said blocks for urging said bus bar and attached unit upwardly upon deactivation of said forcing means.

10. In a device for attaching an electrical unit to a bus bar, a positioning block comprising a base, said base being formed with an upwardly open chamber to receive the electrical unit and a groove extending transversely through the block for receiving the bus bar below the chamber, said groove opening upwardly into the chamber, a cam plate longitudinally disposed and slidably mounted in said block for movement transversely of said groove, said cam plate having a groove registrable with the block groove, said groove in said positioning plate having an inclined wall, resilient means connecting said block and said cam plate and biasing said cam plate in one direction for non-registry of the groove thereof with the block groove, resilient means connecting said block and said positioning plate and biasing said positioning plate in the opposite direction for non-registry of the groove thereof with the block groove, latch means in said block and latching said positioning plate against the biasing of its resilient means with the groove thereof in registry with the block groove, and means in said block adjacent the bottom of the block groove and connecting said latch means for releasing said positioning plate with resultant movement thereof under the biasing urge of its resilient means to a position of non-registry of its groove with the block groove to move the inclined wall into a position 7 partially to restrict the block groove.

blocks to position the bus bars therein extending between the blocks in an inclined position with respect to the base when said pressure plate is positioned vertically, means mounted on the base adjacent said positioning blocks and connecting said pressure plate to swing said bus bar from said inclined position to a vertical position relative to said base responsive to movement of said pressure plate toward a horizontal position, said lastmentioned means including a cam plate carried by each block with portions extending toward the pressure plate, spring means biasing said cam plate into contact with a portion of said pressure plate when said pressure plate is vertically positioned, said portion of said pressure plate swinging outwardly to allow the cam plates to move under urging of their spring means as the pressure plate is tilted from the vertical, and repositioned responsive to its return to the vertical.

12. In a device for attaching electrical units having contact strips to bus bars provided with transverse sockets having socket restricting portions therein, a base, a pres sure plate pivotally mounted on the base for movement from a vertical to a horizontal position with respect thereto, holding means supported on said base and movable in response to contact by one of the bus bars therewith to a position holding and clamping the bus bars with the sockets transversely inclined relative to said base, means on the base for holding electrical units above the bus bar with their contact strips projecting downwardly within the transverse socket and underlying the socket restricting portions, means connecting said pressure plate and said holding means and operable by movement of said pressure plate from the vertical toward the horizontal position to pivot said bus bars about the engaged contact strips into a vertical position relative to said base, whereby said restricting portions are moved laterally outwardly of the sockets, and means canted by said pressure plate for pressing the electrical units downwardly to project the contacts through the sockets to complete the assembly of the bus bars on the unit contact strips.

13. The device of claim 12 in which said bus bar holding means and said means for holding the electrical units comprises a plurality of blocks fixed in aligned spaced relation to said base and are provided with bus bar receiving grooves in parallel spaced relation at the bottom of upwardly open unit positioning chambers in each block, each groove has side walls contoured to permit a bus bar to be held in an inclined position relative to the base and in a vertical position relative to the base, said means connecting said pressure plate and said holding means is a cam slidably supported by each said block for transverse movement relative to the grooves, each cam is biased by resilient means connecting it to its associated block to maintain the bus bars clamped vertically of the grooves, said pressure plate provides a stop surface and said cam is depressed against its resilient means by said stop portion of the pressure plate when said pressure plate is in the vertical position to permit the bus bars to be inclined in the grooves, and said stop portion is swung outwardly with movement of the pressure plate toward the horizontal with said cam being moved by its resilient means and thereby moving the bus bars from said inclined to a vertical position.

References Cited in the file of this patent UNITED STATES PATENTS 1,173,214 Postel Feb. 29, 1916 1,975,422 Hellenbroich Oct. 2, 1934 2,324,009 McDonough July 13, 1943 2,685,126 MacPheat Aug. 3, 1954 2,820,283 Anderson Jan. 21, 1958