US 3001170 A
Description (OCR text may contain errors)
Sept. 19, 1961 D. L. EYRE ETAL 3,001,170
ELECTRICAL CONNECTING DEVICE Filed July 20, 1959 INVENTOR GLENN H. GLUNTZ BY DENZEL L. EYRE 3,601,170 ELECTRIQAL CUNNECTING DEVICE Denael L. Eyre and Glenn H. Gluntz, Harrisburg, Pa., assignors to AMP Incorporated, Harrisburg, Pa. Filed July 20, 1959, Ser. No. 828,384 2 Claims. (Cl. 339-198) This invention relates to devices for forming a common junction among a plurality of electrical conductors.
A known type of connecting device comprises a plurality of terminal-receiving socket members on a common post which is threaded into a nut. A spring surrounds the post and normally biases the plurality of socket members against the post head so that electrical.
terminals can be inserted into the sockets. The nut which accepts the end of the post has a skirt which is coextensive with the spring so that if the post is tightened into the nut, the spring is compressed until the sockets are clamped between the skirt and the head. Upon such clamping of the sockets the terminals are themselves securely clamped in their sockets and cannot be removed. Connecting devices of this type have proved to be very useful in installations requiring a large number of common connections which must be permanent and secure against accidental disengagement but which must be disengageable to permit circuit changes.
An object of the present invention is to provide an improved connecting device of the above described general type but having means to permit a rapid visual determination of whether or not the terminals are clamped in the sockets. A further object is-to provide a connecting device which permits the establishment of a plurality of a common junctions on one post with each of these junctions being electrically insulated from the other junctions on the same post. A further object is to provide a form of socket for terminals of the above described type which has improved electrical characteristics.
These and other objects are provided in a preferred embodiment in which a post extends through a plurality of blocks of conductive metal and is threaded at its opposite end into an opening in a dielectric block. The dielectric block provides a bearing surface which faces the adjacent conducting block and against which this adjacent block can be pressed. A counterboard spacer is interposed between the head of the post and the end of the stack of sockets, and a coil spring is positioned around the post and bears against the shoulder at the counterbore of the spacer. By virtue of this arrangement, when the stack of sockets are only resiliently loaded or pressed together by the spring, the spacer is urged against the head of the post but when the post is threaded into the nut until the spring is fully compressed, this spring is not visible and it is therefore immediately apparent that the stack of sockets is in its locked condition, i.e. the terminals which are received in the sockets cannot be removed. Whether the sockets are in a locked condition or whether they are only loosely biased together by the spring is thus immediately apparent upon inspection of the condition of the spacer. An added feature of the invention is that the post itself provides an insulating surface and dielectric plates are interposed in the stack of conducting plates to form separate common junctions in the same stack. The entire assembly can be easily assembled and disassembled to provide any combination, within the limits of the number of socket members provided, of common junctions for two or more separate conductors.
In the drawings:
FIGURE 1 is a view of the front of a connector module in accordance with the invention;
FIGURE 2 is a side view of the embodiment of FIG- URE l;
nite States Patent by small upstanding FIGURE 3 is a perspective exploded view of the com ponent parts of the preferred embodiment;
FIGURE 4 is a perspective view of a pair of conducting blocks in accordance withthe invention and a tab of the type which the sockets formed by the blocks are adapated to receive; and
FIGURE 5 is a sectional view showing the lower center section of the dielectric member.
In the preferred embodiment of the invention, there is provided a module composed of insulating material such. as an organic plastic comprising a base portion 2 having a pair of hooks -14- on the separator 10 which cooperate withshoulders 16 and hooks 18 on the front side of the module. It will be apparent that the hooks l4 wilkwhen a pair of modules are snapped together, he cammed over the hooks '18 and snapped into the shoulders 16 to lock the parts together.
The post 22 which is threaded into the nut 20 has a threaded end 24, an intermediate portion which has an insulating covering 23, and a head 26 which is slotted to receive a screw driver or other tightening tool. The
blocks or socket members 28 which form the sockets for' the terminals have a central opening 30 through which the screw extends and are beveled at each end 32 to form openings into which the terminals are inserted. A snap ring 27 is provided on the post to retain the socket members in place. The sides 32 of these openings are defined ridges along the lateral edges of the blocks! A: central depression 36 in the blocks cooperates with a similar boss on the tab 38 of the terminal which is crimped at 40 to the end of a wire 42. As is apparent from FIGURE 1, each pair of blocks aligned sockets.
Dielectric separators of plastic or the like 44 are interposed between each pair of blocks 28 so that each pair of blocks forms 1 common junction for two terminals 38. Obviously any number of these separators can be removed to form a common junction for more than two wires. For example, if the lowermost dielectric plate 44 were removed from FIGURE 1, a common junction would be formed by the four lowermost blocks for four wires. Above this lowermost junction, two other junctions would then be formed, each capable of accommodating two wires.
Normally the parts would be as shown at the left in FIGURE 2 with the spring 50 disposed around the uppermost portion of post 22 and bearing against the counterbored section 39 of a spacer 46. The spring thus presses the stack of blocks and dielectric spacers downwardly and the spacer 46 upwardly and the shank of the screw is clearly visible. After the desired terminals have been inserted into the sockets, the screw is threaded into nut 20 until this spring is compressed and the stack of conducting blocks and dielectric plates are clamped firmly b tween bearing surface 8 and the spacer 46 as shown at the right in FIGURE 2.
The salient advantage of connecting devices of the instant type is that a completely secure and permanent con nection can be obtained when the stack of sockets or blocks is in its clamped condition and the terminal can not be removed or the wire disengaged. At the same time, the connections can be rearranged in any desired fashion by merely unclamping the assembly to permit easy with- 28 forms two D drawal of any terminals desired. The instant invention provides a means for immediate determinationofthe condition of the stack of sockets, that is whether or not they are clamped. If any part of the shank of the screw is visible, it is apparent that the stack is not clamped, :but if the spacer is obviouslypressed against the uppermost dielectric spacer or plate or the uppermost block 28, it is apparent that the assembly is clamped. A further'advantageot the invention is that any desired combination of common junctions for any number of wires, within the limits of the total numberof sockets provided, canbe provided on a single clamping post. The-present invention therefore provides a high degree of versatility and flexibflity capable of satisfying widely divergent requirements for common junctions.
It will be apparent that electrical separation of the socket blocks 23 into several groups is possible in the preferred embodiment by virtue of the fact that the spring 59 surrounds the insulated post near the'head thereof rather than at the threaded lower end. By virtuer'of this arrangement the post 22 is not in conducting contact witl'r'any of the socket blocks.
It has been found that connecting-devices inaccordance with the preferred embodiment'have-outstandingly good conducting ability, even when the stack ofconducting blocks are not clamped but are only lightly pressedtogether by the spring. The mating flat surfaces of the-tube and the blocks are believed to contribute materially in this respect in that relatively large intertacial areasbetween. the tabs and block are provided.
.Changes in construction will occur to those skilled "in the art and various apparently different modifications and embodiments may be made without departing from the scope. of the invention. The matter set forth in the foregoing description and accompanying drawings is offered byway-0i illustration only. The-actualsoope of the invention is intended to be defined in the followingclaims.
1. An electrical connecting device for commonly connecting aplurality of wires havingtab type terminals on their ends comprising, a support having=a threaded opening therein and bearing surface adjacentsaid opening, a post having one threaded end extending into said opening andhavinga head at its opposite end, the -intermediate portion of said post having an electrically insulated'surface, a plurality of pairsof conducting ,blocks having aligned central openings in stackedrelationship on said post with said post extending through said openings, dielectric plates separating at least some of said pairs of said conducting blocks from other pairs of said blocks, a counterbored spacer member interposed between said head of said post and the block immediately adjacent said head with the counterbore of said spacer facing said adjacent block, and a coil spring within said ceunterbore and bearingagainst said spacer member and said adjacent block whereby, upon rotation of said screw with concomitant movement thereof into said threaded opening, said spring is compressed until said blocks are securely clamped between said spacer and said bearing surface and tab terminals positioned between adjacent blocks are securely clamped.
2. An electrical connecting device for connecting a plurality of wires having terminals on their-ends comprising, a support having a threaded opening therein and a bearing surface adjacent said opening, a post having a threaded end extending into said opening and having a head at its opposite-end, a plurality of pairs of conducting socket members having aligned openings intermediate their ends, said post extending throughsaid socket members, a spacer having'a central'bore and a counterbore surrounding said post, acoil springsurrounding said post and extending into said counterbore, saidcoil spring being efiective between said spacer and one of said socket members whereby, upon insertion of an electrical terminal into one of the sockets formed by said socket member, said terminal is resiliently clamped by virtue of said spring, and upon rotation of'said screw, said spring is compressed until said socket members are clamped between said spacer and said support and rigidly clamp said terminal.
References Citedin the file of thispatent UNITED STATES PATENTS 848,505 Steinberger Mar. 6, 1907 1,919,952 Knutson July 25, 1933 2,326,327 Brewer .Aug. 10, 1943 2,360,304 McLoughlin et a] Oct. 10', 1944 2,408,979 Hill et a1. July 16, 1946 2,441,393 Buchanan et al. May 11, 1948 FOREIGN PATENTS 440,174 Germany Feb. 1, 1927 694,724 Great Britain July29, 1953 757,366 Great Britain Sept. 19, 1956 awn...