US3441898A

US3441898A - Connection device for electric cables

Info

Publication number: US3441898A
Application number: US628901A
Authority: US
Inventors: Nils Ingvar Nodfelt
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-04-06
Filing date: 1967-04-06
Publication date: 1969-04-29
Anticipated expiration: 1986-04-29

Description

April 29, 1969 N. l. NQDF'ELT 3,441,898

CONNECTION DEVICE FOR ELECTRIC' CABLES Filed April e, 1967 l sheet of 2 e e 214 41u 4a 4b`51`d153 sq? 1C 1b 7 1d 5 5G 10 8 7'G1C l l l l FIG.3

April 29, 1969 N. I. NODFELT CONNECTION DEVICE FOR ELECTRIC CABLES sheet 2 @f2 Filed April 6, 1967 Nwe, l.

United States Patent O 3,441,898 CONNECTION DEVICE FOR ELECTRIC CABLES Nils Ingvar Nodfelt, Jarnvagsgatan 76, Gnosjo, Sweden Filed Apr. 6, 1967, Ser. No. 628,901 Int. Cl. H01r 31/02, 7/06 U.S. Cl. 339-48 4 Claims ABSTRACT OF THE DISCLOSURE Background of invention (1) The invention refers to a device for connecting electric cables, preferably of the multiconnector type, and is especially suited for use with electronic apparatuses where it is desirable that the transfer resistance shall be low.

(2) Connection `devices of known type usually are provided with mating male and female contact members. In the present device two male members are mating.

Summary The invention is essentially characterized by each member having an oblique contact end surface and an intermediate portion having flattened surfaces to form a strip shaped bar, the plane of this bar and the plane of oblique front end surface both being perpendicular to the same axial plane of the contact member. The contact members of one coupling part are slightly off-set in relation to those of the other coupling part so that as the parts are tightened together, the oblique contact surfaces slide against each other to move the contact members sidewards.

The members are fitted into bodies of insulating material which are provided with axially protruding ridges encircling the members and adapted to seal off the contact area from the ambient atmosphere. According to a development of the idea the insulating body is designed to receive the individual members in such a manner that any damaged member may be easily exchanged.

Brief description of the drawings Description of the preferred embodiments For the sake of simplicity only the essential components have been indicated.

FIGURE 1 shows a contact member 1 employed in the connection device illustrated in FIGURES 2 and 3. Each member has a cylindrical front end portion 1a and a back portion 1b the last mentioned being provided with 3,441,898 Patented Apr. 29, 1969 "ice a part-tubular portion 1c adapted to be connected to a conductor (not shown in FIGURE 1). The

end portions

1a and 1b are interconnected by a narrow flat strip or band shaped portion 1d which has a width corresponding to the ydiameter of the rst mentioned end portion. This intermediate portion makes an elastic deformation of the member possible The dimensions of the strip portion are, however, such that any fbending in a direction parallel to said plane is prevented. The front end surface 1e :of the front end portion 1a is obliquely arranged with respect to the longitudinal axis of the member and is designed to slide against a correspondingly shaped contact surface 1e of an adjacent member, when the two contact members are brought together into contact. During this contact operation the front end portion 1a of the engaging mem-bers are deflected by the elastic deformation of the strip-shaped intermediate portions 1d.

The connection device illustrated in FIGURE 2 consists of two

coupling parts

2 and 3 respectively, the com ponents of each part being essentially alike. Each

part

2 and 3 consists of a tubular casing 4 provided with unsymmetrically arranged

ridges

4a and 4b which make a connection of the two

parts

2 and 3 possible in one relative position only. The ends of the casings carrying these ridges and recesses have inner and outer diameters which are slightly larger than the ends of the casings remote from the connection. These enlarged portions of the casings 4 are provided with front end inserts 5 of dielectric and elastic material, preferably rubber. Each insert 5 is .provided with seven axially directed passages as shown in FIGURE 3, each adapted to tightly enclose the front end portion 1a of a contact member. The adjacent end surfaces of the inserts 5 are each provided with an annular ridge 5a. In order to prevent moisture from entering the connecting member said ridges are designed to be brought into close contact with each other when the two contact members of the connecting device are connected. The elastic rubber inserts 5 ensure that the end portions of the contact members are held in definite rest positions and permit a sideways movement during the connection operation of the contact member.

In order to retain the contact members in proper axial positions, which is diflicult to achieve solely by front rubber inserts 5, the end of each

casing

2, 3 remote from the connection joint is provided with a back end insert 6 of comparatively hard synthetic resin, into which the back ends 1b of the members are forced. Each insert 6 is provided with an annular flange 6a at about its middle portion which flange 6a is adapted to rest against the outer end of the casing 4. The -llange is locked against casing 4 by a threaded sleeve 7 provided with a flange 7a cooperating with flange 6a through a packing 8.

The coupling parts are retained in tted position bymeans of

tubular members

14, 15. Member 14 is freely rotatable about the coupling part. They co-operate at their outer ends with anges thereon and are threaded at their meeting portions.

As shown in FIGURE 2, the end portions of the contact members, in their rest position, are somewhat offset in relation to each other. During the connecting operation the oblique contact surfaces will slide upon each other While forcing the top parts of the contact members sideways against the action of the rubber inserts 5 and the resiliency of the mem-bers. During this sliding movement any possible oxide coating on the contact surfaces will be removed and a continued good contact between the members is ensured by the resiliency. As each member consists of a single part only the total transfer resistance between the contacting ends of the cables joined by the conecting means will be insignificant. The risk of oxidation of the connected contact members is comparatively small, since the contact surfaces of the members is completely protected from the influence of the atmosphere by the ridge portions 5a of the rubber inserts.

In the modied connection device shown in FIGURE 4 the member 1, in the same manner as shown in FIG- URES 1-3 is provided with a cylindrical front end portion 1a and a cylindrical back end portion 1b. The last mentioned portion is provided with an elongated sleeve portion 1c adapted to enclose a conductor (not shown). The

end portions

1a, 1b are interconnected by a flat strip or band-shaped intermediate portion 1a'. The front end portion is provided with an oblique contact surface 1e.

The connection device consists of two contact members each containing an insert 6 of dielectric material, for instance a comparatively hard synthetic resin. The insert 6 is provided with the appropriate number of passages 9, of which one only is shown in FIGURES 4 and 5. In the middle part of each passage a ridge 10 is arranged. The back end portion 1b of the Contact member is provided with a transverse recess 11 adapted to co-operate with said ridge 10. The contact member is shaped to be retained within the passage 9 by its own resiliency. The planes of recess 11, the at strip or bandshaped intermediate portion 1d and the oblique contact surface 1e are perpendicular to the same axial plane the longitudinal axis of the contact member. The free opening 12 between the top of the ridge 10 and the opposite wall of the passage 9 is slightly larger than the cross sectional area of the front end portion of the contact member.

The contact member 1 is inserted in the passage 9 with the pointed front end portion 1a first and is pushed inwards until the recess 11 encloses ridge 10. By the form of the member an eicient locking is obtained, the member contacting the passage at three points A, B and C respectively. When the

parts

2 and 3 of the connection member are brought together the oblique contact surface 1e of one member will be forced against the corresponding surface 1e of the adjacent member. During this operation the contact in point C is released while the pressure of the member against the ridge (point B) is increased. When it is desired to replace a contact member an oblong tool is inserted behind the member, i.e. between the side of the member which extends towards the lip of the oblique surface. By means of this tool the end portion `1b may be moved against the action of the resiliency of the member suciently to make possible a release of recess 11 from the ridge 10 so that the member may be removed.

What I claim is:

1. In a connection device for electric cables including two coupling parts adapted to be connected together, each coupling part comprising of a body of insulating material and at least one rod-like contact member carried thereby in a position to mate with a' juxtaposed member in the opposite coupling part, said members at their back ends being connected to conductors in the cables, said members each including an oblique contact front end surface for contacting a corresponding front end surface of the juxtaposed member and an intermediate portion of each member having attened surfaces on its opposite sides to form a narrow strip-shaped bar,

the member in one coupling part being slightly olf-set in relation to the juxtaposed member in the other coupling part so that as the two coupling parts are tightened together, the oblique Contact Surfaces slide against each other and elastically bend the contact members.

2. A connection device according to claim 1 in which the insulating body of each coupling part is provided with an axially protruding ridge encircling the contact members supported by the body and designed to be brought into sealing contact with the juxtaposed ridge of the other coupling part.

3. A connection device according to claim 1 in which the insulating body includes of a back portion for rigidly supporting the back ends of the contacts members and a front portion enclosing the front ends of the contact members, said front and back portions being connected by a tubular member leaving the intermediate portion of the members free.

4. A connection device according to claim 1 in which the individual contact members are located in bores in a comparatively rigid body of insulating material, there being a recess in the back end portion of the member and a correspondingly shaped ridge in the wall of the bore, the free opening between the ridge and the opposite wall of the bore being slightly larger than the cross sectional area of the front end portion of the member.

References Cited UNITED STATES PATENTS 397,553 2/1889 Johnston 339-49 XR 2,572,448 10/ 1951 Child. 2,638,573 5/1953 Glickman et al. 2,972,728 2/1961 Cole 339-64 3,185,955 5/1965 Keller 339-91 MARVIN A. CHAMPION, Primary Examiner. PATRICK A. CLIFFORD, Assistant Examiner.

U.S. Cl. X.R.