GB2223358A

GB2223358A - Push button switch

Info

Publication number: GB2223358A
Application number: GB8918511A
Authority: GB
Inventors: Takahiko Enei
Original assignee: Alps Electric Co Ltd
Current assignee: Alps Alpine Co Ltd
Priority date: 1988-09-24
Filing date: 1989-08-14
Publication date: 1990-04-04
Also published as: GB8918511D0; JPH0629858Y2; JPH0246333U

Abstract

A push button switch which includes a pair of legs (7) each spaced by a clearance distance d from a housing (3) for supporting the switch on a printed circuit board further includes protrusions (7a, 3a, 3b) on the facing surfaces of the legs and housing. These protusions serve to eliminate the possibility, during a tape automated installation process of installing the switches on the printed circuit board, of the legs of one switch entering the clearance gap of a second switch and becoming jammed therein. <IMAGE>

Description

PUSH BUTTON SWITCH The present invention relates to a push button switch including a frame for enabling it to support itself on a printed circuit board. In particular, the invention relates to a push button switch including a frame and which is held, together with a plurality of similar switches, by a tape for mounting onto a printed circuit board or similar.

The object of the present invention is to provide a push button switch attached with a frame which is capable of positively preventing an inserting accident of the legs of frame when taped, and particularly to prevent the legs of two switches being entangled together, so that automatic installation can be satisfactorily achieved.

In order to attain this object, the present invention comprises a construction in which some protrusions are formed on the internal surface of the legs of a frame and at least on one side surface of each facing surface with said legs of a housing.

According to the present invention there is provided a push button switch comprising a switch main body protruded with a push button at the top of a housing, a frame fixed on a surface of said housing and including legs for self-supporting the switch, extending alongside both sides of said housing with each end portion, and terminals protruded at a side of said housing wherein a plurality of protrusions are formed at each internal surface of said legs and also at least on one side surface of two surfaces of said housing facing with said legs.

According to the present invention, there is further provided a push button switch including a leg, extending at least partially alongside but spaced from a housing and a protrusion on the surface of at least one of the facing surfaces of the leg and housing.

When a switch is constructed as abovementioned, even if a leg of one push button switch facing another in the taped state is located adjacent a clearance between a leg and a side surface of a housing of the other push button switch, since the protrusions on each internal surface of the legs and the protrusions on both side surfaces of a housing limits the location of the legs so that the insertion into the clearance can be prevented, then there is less risk of the push button switches becoming coupled together.

Embodiments of the present invention will now be explained by way of example only with reference to the accompanying drawings, in which: Fig. 1 is a bottom view of a push button switch according to the present invention; Fig. 2 is a side view taken from the direction of arrow A in Fig. 1; Fig. 3 is a side view taken from the direction of arrow B in Fig. 1; and Figs. 4 to 6 show a previously available switch and mounting method.

A conventional example of a push button switch of this kind is shown in Fig. 4. A push button switch 1 comprises a switch main body 2 having a handling button 4 mounted at the top of a boxshaped housing 3 which is assembled with contacts or springs etc. A pair of terminals 5 protrude from a side of the housing 3 by extending from fixed contact points within the housing. A metal frame 6 is fixed on the top surface of said housing 3 and both end portions of this are processed by bending substantially perpendicular thereto. Both end portions of the frame 6, extending along with the side surfaces of the housing 3, serve as legs 7 for self-supporting this push button switch 1 on a printed circuit board which is not shown.

The push button switch 1 may be mounted automatically on a printed circuit board by using an automatic mounting machine. To enable this they are radially taped as shown in Fig. 5. That is, the extending portions of each terminal 5 are releasably fixed on one edge of a long band-like means 10 made of thick paper or the like by using an adhesive tape 11, so that a plurality of push button switches 1 are held to the band-like means 10 with predetermined spacing between switches. Subsequently, the push button switches 1, held by the tape, are fed to the automatic mounting machine. The band-like means of tape 10 is moved intermittently by utilizing the conveying holes 12 so that the push button switches 1 cut out with a part of the extending portion of each terminals 5 are sequentially installed on the printed circuit board.

The legs 7 of each push button switch are formed by bending both end edge portions of frame 6 after fixing on the top surface of the housing 3. In order to prevent an invasion of a flux or solder according to a capillary phenomenon, a clearance d (shown in Fig. 5) of about 2.0 mm is formed between a leg 7 and a side surface of the housing 3. However, the band-like means 10 which holds these push button switches 1 is generally successively folded for holding in a hand as shown in Fig. 6, hence there may arise a case in which a leg 7 of one push button switch 1, which faces another push button switch is inserted into the clearance d of the other push button switch 1 so that it becomes impossible or very difficult to disengage.In such a case, the folded band-like means 10 becomes impossible to unfold, so that the automatic installation of the push button switches 1 becomes impossible to execute.

A push button switch shown in Figs. 1 to 3 is formed with a protrusion 7a on an internal surface of legs 7 which enables the switch to be selfstanding or self-supporting. The legs are formed by bending both end portions of a frame 6 made of metal plate. Also, large and small protrusions, respectively 3a, 3b are formed on the surfaces of the housing 3 which are adjacent legs 7. Protrusions 7a are formed by pressing upon cutting out a frame 6 by a press machine, and the protrusions 3a, 3b are formed integrally with the housing upon moulding the housing 3 within a metal mould by an injection moulding machine. Other parts not labelled in Figs.

1 to 3 are the same as conventional parts explained with reference to Figs. 4 to 6.

The protrusions 3a, 3b, 7a of push button switch 1 serve to prevent the legs of other push button switches being inserted into the clearance d between a leg 7 and a housing of one push button switch. That is to say, even though a push button switch 1 is radially taped by a band-like means 10 made of thick paper or the like prior to installation, and this band-like means is successively folded, so that the legs 7 of one puh button switch 1 are located adjacent the clearance d of another push button switch 1, the legs 7 of the first switch are limited by the protrusions of the second switch so that it becomes difficult to locate the leg within clearance d, even when protrusions 7a are insufficient, they are limited by the protrusions 3a, 3b, so that it is impossible to enter into the clearance d.Therefore, there is less chance that the legs 7 of one push button switch 1 in a taped state is inserted into the clearance d of another push button switch 1; that is to say, the coupling by insertion of the push button switches into each other, which has been a problem heretofore, can be substantially or wholly avoided, so that installation can be satisfactorily achieved. Furthermore, all of the protrusions 3a, 3b, 7a can easily be formed, without significantly increasing the material cost and difficulty of processing.

Further, although in the above embodiment, the protrusions are provided at both internal surfaces of legs 7 and on the side surfaces of a housing 3, even if the protrusions are provided at either one of them, there is still an effect preventing the inserting accidents of the legs 7.

As described above, according to the present invention, since the protrusions are formed on the internal surface of the legs of a frame and on the side surfaces of a housing, an incident in which the legs of one push button switch are inerted into the clearance between a leg and a housing of a second push button switch, when mounted in a taped state is unlikely to arise, therefore satisfactory installation can be achieved.

Claims

1. A push button switch comprising a switch main body protruded with a push button at the top of a housing, a frame fixed on a surface of said housing and including legs for self-supporting the switch, extending alongside both sides of said housing with each end portion, and terminals protruded at a side of said housing wherein a pluralityof protrusions are formed at each internal surface of said legs and also at least on one side surface of two surfaces of said housing facing with said legs.

2. A push button switch including a leg, extending at least partially alongside but spaced from a housing and a protrusion on the surface of at least one of the facing surfaces of the leg and housing.

3. A push button switch as claimed in claim 2 including protrusions on the facing surfaces of both the leg and housing.

4. A push button switch as claimed in claim 2 or claim 3 including two protrusions of different size on a surface of the housing.

5. A push button switch as claimed in any one of claims 2 to 4 including two legs, each extending at least partially alongside and spaced from the housing and a protrusion on at least one of the facing surfaces of each respective pair of Facing surfaces of the housing and leg.

6. A push button switch substantially as hereinbefore described with reference to, and as illustrated by, Figs. 1 to 3 of the accompanying drawings.