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(11) | EP 0 157 551 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Electrical components |
| (57) An assembly for an electrical component, especially for a base of a rotary electric
switch, comprises first and second superimposable base parts. The first part has edge
indentations to receive a plurality of terminals, suitably after connection of cables.
On superimposition of the base parts the terminals are located and locked in the composition
base so formed. |
[0001] This invention relates to electrical components, e.g. switches, and particularly to assemblies therefor.
[0002] Rotary electric switches commonly have terminals which also act as the stationary contact members engaged successively by the moving contact members on the rotors. Each terminal is inserted through slots in the switch base from the prospective interior side of the base and then the feed and load cables are attached to the terminals projecting from the exterior side; soldering is usually employed because of limitation of space but even so the attachment requires skill to obtain a reliable joint and is time consuming.
[0003] An object of the invention is to so design a base for an electrical component that the attachment of cables thereto is facilitated.
[0004] In accordance with one aspect of the invention, an assembly for an electrical component comprises first and second base parts which are superimposable to form a base, and a plurality of terminals which are individually receivable in edge indentations of the first base part, after connection with cables as desired, the arrangement being such that superimposition of the two base parts locates and locks the terminals in the composite base. The cables then may be attached to the terminals when separate from the base and the terminals located in the base thereafter. Techniques, such as crimping, which are easier and quicker than soldering may then be used for cable attachment.
[0005] A second, more limited, aspect of the invention resides in an electric switch assembly comprising a first discoid base part having indentations extending to the edge thereof, a plurality of terminals individually receivable in the indentations and shaped to prevent movement of the terminals axially of the first base part, and a second discoid base part which is superimposable on the first base part to form a composite switch base and which has slots therethrough for the reception of portions of the terminals when received in the indentations, and projections receivable in the indentations to locate and lock the terminals in position. When the switch is a rotary electric switch, those portions may form the stationary contact members.
[0006] The invention includes a method of securing cables to an electric component, in which the cables are first secured to the terminals which are then introduced into the first base part of the composite base described above and then locked in position by superimposing the second base part. After the base parts are superimposed, they may be permanently secured together, as by welding where the parts are thermoplastic resins.
[0007] The invention will be more readily understood by way of example from the following description of an electric switch base and a method of attaching cables thereto, reference being made to the accompanying drawings, in which
Figures 1A and 1B are respectively a plan view and an under-plan view of the first of two base parts, and Figure 1C is a section on the line I-I of Figure 1B,
Figures 2A and 2B are respectively an under-plan view and a plan view of the second of two base parts, and Figure 2C is a section on the line II-II of Figure 2A,
Figures 3 to 7 show the terminals of the switch,
Figures 8 and 9 illustrate the crimping of a cable to a terminal in side view and section respectively, and
Figure 10 is a plan view of the completed base, the connecting cables being omitted for convenience.
[0008] The switch base and terminals shown in the drawings are those for an automobile rotary ignition switch which controls large electric current and which is small in size. The technique illustrated may however be employed in other switch applications.
[0009] The base parts shown in Figures 1 and 2 are made of an electrically insulating material and preferably a thermoplastic material, such as filled nylon. They are of generally circular discoid form. When the two parts are superimposed they form a composite switch base.
[0010] The first base part 10 (Figures 1) is formed with a number of indentations corresponding to the number of terminals required and having widths corresponding to the widths. of the individual terminals to be received in them; five indentations 12 - 16 are shown. Indentation 14 has its edges undercut at 17. On the upper side, the base part has an integral L-shaped projection 18 overlying indentation 13. The edges of each indentation have opposed pips 19.
[0011] The second base part 20 (Figure 2) has an equal number of slots 22 - 26 extending therethrough and a projecting block 32 - 36 adjacent each slot and between the respective slot and the edge of the base part.
[0012] The terminals 42 - 46 (Figures 3 to 7) are made of relatively thick copper strip and each has a slot 52 - 56. In addition, each of terminals 42 and 44 to 46 has a pair of opposed side recesses 62 and 64 - 66. Terminal 43 has an offset T-head 63.
[0013] In the manufacture of the switch, the feed and load cables are first attached to the terminals 42 - 46, preferably by the crimping technique shown in Figures 8 and 9. One leg of a crimping sleeve 47 is inserted in the slot 52 - 56 of the terminal so that the sleeve surrounds the lower part of the terminal, the bared cable 48 is laid over that part within the sleeve, and sleeve is crimped as in Figure 9.
[0014] Next, the five terminals are introduced radially into the indentations 12 - 16 of the first base part 10 until they pass and are retained by the pips 19. In the case of terminals 42, 45 and 46 the edges of the respective indentations 12, 15 and 16 are located in the slots 62, 65 and 66. In the case of terminal 44, the slots 64 receive the undercut edges 17 while, in the case of terminal 43, shoulders 67 are located on the upper face of the base part 10 and shoulder 68 is located against the head of projection 18. All terminals are thus held against movement normal to the plane of the base part 10.
[0015] The second base part 20 is then superimposed on the first base part so that the upper parts of the terminals 42 - 46 are received in slots 22 - 26 and the projections 32 - 36 are received in the indentations 12 - 16 (Figure 10). The projections bear against the sides of the terminals and lock the latter in position against radial movement in the base parts 10 and 20. The terminals project slightly above the upper face of second base part 20 and constitute the stationary contact member of the rotary switch.
1. An assembly for an electrical component comprising a base and a plurality of terminals
mounted in said base, characterised in that the base comprises superimposable first
and second base parts (10, 20), the terminals (42 - 46) are individually receivable
in edge indentations (12 - 16) of the first base part (10), after connection with
cables as desired, and the arrangement is such that superimposition of the two base
parts (10, 20) locates and locks the terminals (42 - 46) in the composite base.
2. An assembly according to claim 1, characterised in that the second base part (20)
has slots (22 - 26) to receive portions of the terminals (42 - 46) when received in
the indentations (12 - 16) and projections (32 - 36) receivable in the indentations
(12 - 16) to locate and lock the terminals (42 - 46) in position.
3. An assembly according to claim 1 or 2, characterised in that the edge indentations
(12 - 16) have widths corresponding to the widths of the individual terminals (42
- 46) to be received therein, the edges of each indentation (12 - 16) having opposed
pips (19) for retention of the terminals (42 - 46) in the first base part (10).
4. An electric switch assembly comprising a base and a plurality of terminals mounted
in said base, characterised in that the base comprises a first discoid base part (10)
having indentations (12 - 16) extending to the edge thereof, the terminals (42 - 46)
being individually receivable in the indentations (12 - 16) and shaped to prevent
movement of the terminals (42 - 46) axially of the first base part (10), and a second
discoid base part (20) superimposable on the first base part (10) to form a composite
switch base, the second base part (20) having slots (22 - 26) therethrough for the
reception of portions of the terminals (42 - 46) when received in the indentations
(12 - 16) and projections (32 - 36) receivable in the indentations (12 - 16) to locate
and lock the terminals in position.
5. An electric switch assembly according to claim 4 for a rotary electric switch,
characterised in that said portions of the terminals (42 - 46) received by said slots
(22 - 26) form stationary contact members for said rotary electric switch.
6. An assembly according to any one of the preceding claims, characterised in that
said terminals (42 - 46) have been connected to cables by means of crimping.
7. An assembly according to claim 6, characterised in that said terminals (42 - 46)
and cables (48) are attached by crimping sleeves (47).
8. A method of securing cables to an electrical component comprising a base and a
plurality of terminals, characterised in that the method comprises securing the cables
(48) to the terminals (42 - 46), introducing the terminals secured to the cables into
a first base part (10) having edge indentations (12 - 16) to individually receive
said terminals (42 - 46) and then locking the terminals (42 - 46) in position by superimposition
on the first base part (10) of a second base part (20).
9. A method according to claim 8, characterised in that the cables (48) and terminals
(42 - 46) are secured by crimping.
10. A method according to claim 8 or 9, characterised in that the first and second
base parts (10, 20) are subsequently permanently secured together.