GB1604104A - Variable resistor - Google Patents

Description

(54) A VARIABLE RESISTOR (71) I, KONOE ONODA, a Japanese citizen, of 4607 No. 1 Koyama l-chome, Shinagawa-ku, Tokyo, Japan, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to variable resistors.

Conventionally, assembling a third or wiper terminal in a variable resistor is carried out by fitting one end of the third terminal on to a rotatable shaft and mounting the other end on the casing of the variable resistor with rivets. This method of assembly is not very good because skill is needed in the rivetting and the resulting productivity rate is very low.

An object of this invention is to provide a variable resistor in which a third or wiper terminal is fitted simply and rapidly without the need for rivets.

According to the present invention there is provided a variable resistor comprising a casing, at least two terminals and a rotatable shaft, at least one of the terminals being engagable with the shaft and having snapacting means cooperating with a wall of an aperture in the casing to retain said terminal and said casing together.

Preferably, the snap-acting means comprises a lug integral with the terminal and attached to another lug projecting from the terminal which has a pair of paralleljaws for fitting engagingly round the rotatable shaft.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a cross-sectional view of a variable resistor according to one embodiment of the present invention in which a sliding means is not shown; Fig. 2 is a sectional view taken along line A-B of Fig. 1; Fig. 3 is a perspective view of a third terminal; and Fig. 4 shows front elevations of two modifications of a lug projecting from the third terminal.

An abutment wall (3) of a casing 1 of a variable resistor is located between the ends of an inverted U-shaped resistance unit 2, which is fixed to the casing 1 of the variable resistor.

A stepped aperture 4 in the casing 1 has a small portion contiguous with a larger portion. The small portion is open to the outside of the casing 1 and extends inwardly; its width is substantially the same as the width of a lug 8 of the third terminal 7 and it leads into the larger portion which is open to the inside of the casing 1.

A gripping portion 6 at the end of the third terminal has two parallel jaws to fit round the rotatable shaft 5, the shaft being provided with conventional sliding means (not shown). The shaft is able to rotate relative to the third terminal but axial movement therebetween is not allowed.

The lug 8 projects perpendicularly from the third terminal 7 at the centre thereof and is substantially the same width as the small portion of the stepped aperture as stated. The lug is long enough to extend from the opening of the small portion of the stepped aperture 4 into the larger portion thereof when the gripping portion 6 is fitted into the rotatable shaft 5. A second lug 9 is resilient and is formed out of the centre of the first lug 8 or from one end thereof.

The second lug may, alternatively, be formed so that it extends from one side of the first lug or from the top of the first lug, as shown in Fig. 4.

The third terminal is placed against the casing with the lugs facing the stepped aperture 4 and the first lug 8 is inserted, thus depressing the second lug thereon, through the opening of the small portion into the large portion so that the second lug springs into abutment with the wall above where the small aperture meets the large aperture.

The first lug 8 fits snugly in the small aperture portion and the third terminal in then firmly mounted in place.

Further, the second lug extends into the large aperture portion and automatically springs into place with the result that the third terminal is firmly accommodated without slipping off the shaft.

Thus according to the present invention attaching a third or wiper terminal to a variable resistor is carried out simply and quickly without rivetting.

Also, as no rivets are required, the cost of assembling variable resistors is reduced.

WHAT I CLAIM IS: 1. A variable resistor comprising a casing, at least two terminals and a rotatable shaft, at least one of the terminals being engagable with the shaft and having snapacting means cooperating with a wall of an aperture in the casing to retain said terminal and said casing together.

2. A variable resistor according to claim 1, in which the snap-acting means comprises a lug integral with the said terminal.

3. A variable resistor according to claim 2 in which the said lug is attached to another lug projecting from the said terminal.

4. A variable resistor according to claim 1, 2 or 3 in which the said terminal has a pair of parallel jaws for fitting engagingly round the rotatable shaft.

5. A variable resistor constructed and arranged as hereinbefore described with reference to and as illustrated in the accompanying drawings.

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

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. large portion so that the second lug springs into abutment with the wall above where the small aperture meets the large aperture. The first lug 8 fits snugly in the small aperture portion and the third terminal in then firmly mounted in place. Further, the second lug extends into the large aperture portion and automatically springs into place with the result that the third terminal is firmly accommodated without slipping off the shaft. Thus according to the present invention attaching a third or wiper terminal to a variable resistor is carried out simply and quickly without rivetting. Also, as no rivets are required, the cost of assembling variable resistors is reduced. WHAT I CLAIM IS:

1. A variable resistor comprising a casing, at least two terminals and a rotatable shaft, at least one of the terminals being engagable with the shaft and having snapacting means cooperating with a wall of an aperture in the casing to retain said terminal and said casing together.

2. A variable resistor according to claim 1, in which the snap-acting means comprises a lug integral with the said terminal.

3. A variable resistor according to claim 2 in which the said lug is attached to another lug projecting from the said terminal.

4. A variable resistor according to claim 1, 2 or 3 in which the said terminal has a pair of parallel jaws for fitting engagingly round the rotatable shaft.

5. A variable resistor constructed and arranged as hereinbefore described with reference to and as illustrated in the accompanying drawings.