GB1580264A

GB1580264A - Electrical terminals

Info

Publication number: GB1580264A
Application number: GB3900977A
Authority: GB
Original assignee: Siemens Corp
Current assignee: Siemens Corp
Priority date: 1976-09-20
Filing date: 1977-09-19
Publication date: 1980-11-26
Also published as: DE2642262A1; JPS5337886A; SE424937B; SE7710253L; DE2642262C3; FR2365221B1; DK412477A; CH619566A5; DK148573B; DE2642262B2; DK148573C; FR2365221A1

Abstract

The present invention serves the purpose of connecting electric lines to devices by means of a box terminal (4, 5, 6), which is inserted into a corresponding opening (3) of the housing (1) of the device. Provided in this case is a terminal fitting (6) which is constructed as a strip-shaped stamped bent part. Bent out at right angles approximately from the middle of the strip is a thrust pad which penetrates the box-shaped terminal body (4). One end (11) of the terminal fitting (6) is constructed as a terminal lug for an electrical connection, and is to be provided with hook-shaped tabs (12) for insertion in a self-closed fashion into a groove (20) of the housing (2). The other end (13) of the terminal fitting (6) is bent at right angles with respect to the thrust pad (9) approximately at the distance of the length of the shaft of the clamping screw (5) and provided with a fork-shaped opening (14) in such a way that the neck (15) of the clamping screw (5) can be locked home in a recess (19). <IMAGE>

Description

(54) ELECTRICAL TERMINALS (71) We, SIEMENS AKTIENGES ELLSCHAFT, a German company of Berlin and Munich, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to electrical terminals.

According to the present invention, there is provided an electrical terminal comprising: an electrically conductive body having first and second parallel extending portions, and a third portion for insertion into a housing adapted to receive the terminal, said first portion having two wall portions which define therebetween an opening having a narrow portion leading to an enlarged recess, said first and third portions being disposed at or adjacent opposite respective ends of the body, said second portion being disposed intermediate said first and third portions, and said third portion being provided with at least one hook-like projection for snap engaging a corresponding portion of a housing to secure the body therein; an electrically conductive screw arranged to engage in said recess having a head, a screw threaded first shank portion, and a reduced diameter second shank portion between the head and the first shank portion, the diameter of said head and said first shank portion being greater than that of said recess, the diameter of said second shank portion being less than that of said recess and slightly greater than the width of said narrow portion such that said second shank portion can be inserted therethrough into said recess by resiliently urging said wall portions apart, and the length of the shank of the screw being substantially equal to the distance between said first and second body portions; and an electrically conductive clamping member which has an aperture for the passage therethrough of said second body portion and has a portion for threaded engagement with said screw such that, upon turning the screw, a face of said aperture is moved towards and away from a corresponding face of said second body portion, to provide clamping of an electrical conductor between said faces in use of the terminal.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawing, in which: Figure 1 is a sectional perspective view of an electrical terminal in accordance with the invention; Figure 2 is a perspective view of an electri- cally conductive body of the terminal; and Figure 3 shows a pressure screw of the terminal.

In Figure 1, a housing 1 of an electrical apparatus, for example, a relay, is provided with a housing portion 2 which accommodates a plurality of frame terminals, which are located in individual apertures 3 separated by ribs 8. Each terminal comprises an electrically conductive body 6, mounted in a respective aperture 3, together with an electrically conductive pressure screw 5, and an electrically conductive clamping member 4.

The body 6 and screw 5 are illustrated individually in Figures 2 and 3 respectively.

The body 6 is conveniently formed by stamping and subsequent bending of sheet metal, and comprises first and second parallel extending portions 13 and 9. The upper (as seen in Figure 2) body portion 13 has two wall portions which define therebetween an opening 14 having a narrow portion leading to an enlarged recess 19. The lower body portion 9 is bent upwardly at its free end 10. The lower end 11 of the body 6 constitutes a third body portion which is formed as a lug for use as a plug-in electrical connector, for example as an AMP plug. Towards the lower end 11, the body is provided with a central elongate slot 22, and with two oppositely facing hook-like projections 12.

The screw 5 has a head, a screw-threaded first shank portion 16, and a reduced diameter second shank portion 15, between the head and portion 16. A further reduced diameter shank portion 17 is provided at the free end of the screw 5.

The clamping member 4 is provided with an aperture for the passage therethrough of the lower body portion 9, as shown in Figure 1. Thus, the clamping member 4 has a base portion 25 below the aperture and an upper portion above the aperture. The upper portion of the clamping member 4 is provided with a screw thread 18, for threaded engagement with the portion 16 of the screw 5.

The illustrated terminal is assembled as follows.

Firstly, the shank portion 17 of the screw 5 is engaged in the screw threaded bore 18 of the clamping member 4. Then, the lower portion 9 of the body 6 is passed through the aperture in the clamping member 4 whilst the reduced diameter shank portion 15 of the screw 5 is snap engaged into the recess 19 in the upper portion 13 of the body 6. To this end, the diameters of the head and screw threaded portion 16 of the screw 5 are greater than that of the recess 19, and the diameter of the reduced shank portion 15 is less than that of the recess and slightly greater than the width of the narrow portion of the opening 14. Thus, as the shank portion 15 of the screw 5 is pushed through the opening 14, the walls of the opening are resiliently urged apart, to allow the shank portion 15 to be snapped into the recess 19.

The screw 5 is thus made captive in the body 6, and the bent end 10 of the lower body portion 9 assists in holding the clamping member 4 in place. Of course, it is necessary for the length of the shank portion 15 to be greater than the thickness of the sheet metal from which the body 6 is formed.

The assembled parts 4, 5 and 6 are then introduced in to the respective aperture 3 downwardly from above (as seen in Figure 1), to take up the position illustrated in Figure 1. To this end, the housing portion 2 is formed with a respective slot 20, the width of which is substantially equal to the thickness of the body 6, and the length of which is equal to the width of the end 10. As the body 6 is inserted into its respective aperture 3, the hook like projections 12 are resiliently urged towards one another, and eventually snap-engage under a lower side 21 of the housing portion 2. The slot 22 allows the necessary elastic deformation of the lower end 11 of the body 6. The upper body portion 13 extends from the body 6 for a distance greater than does the lower body portion 9, and an end 23 thereof abuts a respective shoulder 24 in the housing portion 2, between the body portions 9 and 13. As shown in Figure 1, the upper face of the base 25 of the clamping member 4, and the lower face of the lower body portion 9, are disposed adjacent an aperture 7 in the housing portion 2, which aperture is surrounded by a flared mouth.

The terminal is used as follows.

Upon turning the screw 5, the clamping member 4 can be moved upwardly and down wardly as seen in Figure 1, to bring the oppos ing faces of the base 25 and pody portion 9 towards and away from one another. Thus, an electrical conductor inserted through the aperture 7 can be clamped between these faces, upon tightening the screw 5. As indi cated above, the lower end 11 of the body 6 is electrically connected to internal wiring of the apparatus (such as a relay) inside the housing 1, and an electrical connection can therefore be made between the internal wiring and the conductor inserted through the aper ture 7.

In Figure 1, the terminal is shown in the fully open position. In the fully closed posi tion of the terminal, the opposing faces of the face 25 and body portion 9 are clamped to gether. As shown in Figure 1, the length of the shank of the screw 5 is substantially equal to the distance between the upper and lower body portions 13 and 9. Due to this con figuration, a reliable electrical connection between the screw 5 and the body 6 can be obtained upon applying the pressure downwardly on the head of the screw 5, whether the terminal is open, closed or partially closed. Thus, when a test probe is applied to the head of the screw 5, electrical connection with the body 6 is always obtained, either by the head of the screw 5 bearing against the top of the body portion 13, or by the free end of the shank bearing against the upper face of the body portion 9, or by the upper portion of the clamping member 4 bearing against the upper face of the body portion 9. This is of particular advantage insofar as automatic testing of the apparatus within the housing can be carried out, irrespective of whether the terminals such as illustrated are open or closed. This is of great advantage over previously proposed terminals of which we are aware, in which it is necessary to close the terminals in order to carry out testing.

The illustrated terminal readily lends itself to automatic assembly. Thus, the apparatus in the housing 1 can be provided with terminals as illustrated on an automatic assembly machine, and then automatically tested with the terminals open. The tested apparatus can then be sent directly to a customer with the terminals already open, which is often of great advantage to a customer. Because the screw 5 is held captive in the body portion 13, there is virtually no chance of losing such screws in transit of the apparatus, even with the terminals open.

It may be appreciated that the illustrated terminal can be manufactured and assembled in a relatively simple manner. In particular, production of the body 6 involves only simple stamping and bending operations. Due to the nature of the terminal, the terminal can be introduced directly into the housing portion 2, which is formed integrally with the main housing 1 of the apparatus. Of course, the length of the screw threaded portion 16 of the screw 5 is such that, in clamping electrical conductors of both maximum and minimum permissible cross-sections, sufficient turns of the portion 16 engage the screw thread 18 of the clamping member 4.

WHAT WE CLAIM IS:- 1. An electrical terminal comprising: an electrically conductive body having first and second parallel extending portions, and a third portion for insertion into a housing adapted to receive the terminal, said first portion having two wall portions which define therebetween an opening having a narrow portion leading to an enlarged recess, said first and third portions being disposed at or adjacent opposite respective ends of the body, said second portion being disposed intermediate said first and third portions, and said third portion being provided with at least one hook-like projection for snap engaging a corresponding portion of a housing to secure the body therein; an electrically conductive screw arranged to engage in said recess having a head, a screw threaded first shank portion, and a reduced diameter second shank portion between the head and the first shank portion, the diameter of said head and said first shank portion being greater than that of said recess, the diameter of said second shank portion being less than that of said recess and slightly greater than the width of said narrow portion such that said second shank portion can be inserted therethrough into said recess by resiliently urging said wall portions apart, and the length of the shank of the screw being substantially equal to the distance between said first and second body portions; and an electrically conductive clamping member which has an aperture for the passage therethrough of said second body portion and has a portion for threaded engagement with said screw such that, upon turning the screw, a face of said aperture is moved towards and away from a corresponding face of said second body portion, to provide clamping of an electrical conductor between said faces in use of the terminal.

2. A terminal according to claim 1, wherein said body has been formed by stamping and subsequent bending of sheet metal.

3. A terminal according to claim 1 or 2, wherein said first and second body portions extend substantially at right angles to the remainder of said body.

4. A terminal according to claim 1, 2 or 3, wherein said third body portion is formed as a lug for use as a plug-in electrical connector.

5. A terminal according to claim 1, 2, 3 or 4, wherein said body is mounted in a housing having an aperture adjacent which said faces extend, for clamping an electrical conductor inserted through said aperture in use of the terminal.

6. A terminal according to claims 4 and 5, wherein two oppositely facing hook-like projections are provided on said third body portion, for snap-engaging corresponding portions in said housing to secure said body therein.

7. A terminal according to claim 5 or 6, wherein said housing is formed with a flared mouth around said aperture in the housing.

8. A terminal according to any preceding claim, wherein said second body portion extends from a central portion of said body.

9. A terminal according to any preceding claim, wherein said screw has a further reduced diameter shank portion at the free end thereof.

10. A terminal according to claim 5 or to any one of claims 6 to 9 as appendant thereto, wherein said first body portion extends from said body for a distance greater than that for which said second body portion extends, and abuts a shoulder in the housing between said first and second body portions.

11. A terminal according to claim 6 or to any one of claims 7 to 10 as appendant there to, wherein said third body portion is formed between said hook-like projections with an elongate slot.

12. An electrical terminal according to claim 1 comprising an electrical terminal member substantially as hereinbefore described with reference to Figure 2 of the accompanying drawing.

13. An electrical terminal substantially as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawing.

14. Electrical apparatus provided with a terminal according to any preceding claim.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. terminal can be manufactured and assembled in a relatively simple manner. In particular, production of the body 6 involves only simple stamping and bending operations. Due to the nature of the terminal, the terminal can be introduced directly into the housing portion 2, which is formed integrally with the main housing 1 of the apparatus. Of course, the length of the screw threaded portion 16 of the screw 5 is such that, in clamping electrical conductors of both maximum and minimum permissible cross-sections, sufficient turns of the portion 16 engage the screw thread 18 of the clamping member 4. WHAT WE CLAIM IS:-

1. An electrical terminal comprising: an electrically conductive body having first and second parallel extending portions, and a third portion for insertion into a housing adapted to receive the terminal, said first portion having two wall portions which define therebetween an opening having a narrow portion leading to an enlarged recess, said first and third portions being disposed at or adjacent opposite respective ends of the body, said second portion being disposed intermediate said first and third portions, and said third portion being provided with at least one hook-like projection for snap engaging a corresponding portion of a housing to secure the body therein; an electrically conductive screw arranged to engage in said recess having a head, a screw threaded first shank portion, and a reduced diameter second shank portion between the head and the first shank portion, the diameter of said head and said first shank portion being greater than that of said recess, the diameter of said second shank portion being less than that of said recess and slightly greater than the width of said narrow portion such that said second shank portion can be inserted therethrough into said recess by resiliently urging said wall portions apart, and the length of the shank of the screw being substantially equal to the distance between said first and second body portions; and an electrically conductive clamping member which has an aperture for the passage therethrough of said second body portion and has a portion for threaded engagement with said screw such that, upon turning the screw, a face of said aperture is moved towards and away from a corresponding face of said second body portion, to provide clamping of an electrical conductor between said faces in use of the terminal.