Interlocking gang push-button switch

Disclosed is an assembly of ganged push-button switches each movable between a first position and a latching position. The assembly is comprised of a first switch block and a second switch block connected thereto. The operation rod of each push-button switch is formed with a symmetrical cam portion engaging a single latch member common to both blocks of switches so that any switch previously locked into its latched position will be unlatched by the latch member upon actuation of any one of the switches.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an interlocking ganged push-button switch 
which includes an interlocking mechanism therefor and, more particularly, 
to an improved interlocking ganged push-button switch of a simple 
construction provided with miniaturized cam means and an interlocking 
mechanism which is accurately and smoothly operated. 
2. Description of the Prior Art 
There have been interlocking ganged push-button switches provided with an 
interlocking mechanism, the construction of one form of such switch will 
be described in detail below. In such an interlocking ganged push-button 
switch, however, two cams and two links are combined together to interlock 
the push-buttons of such switches. Consequently, errors in dimensions of 
the contacting portions of the cams and links are accumulated and proper 
strokes of the cams are difficult to obtain. This prevents accurate and 
smooth operation of the interlocking ganged push-button switch. 
SUMMARY OF THE INVENTION 
An object of the present invention is to eliminate the above-described 
drawbacks encountered in the prior art interlocking ganged push-button 
switch, by simultaneously operating push-button switches in switch blocks. 
To this end, according to the present invention, there is provided an 
interlocking ganged push-button switch comprising a first switch block 
including a first frame member, a plurality of first push-button switches 
supported by the first frame member and having a pair of symmetrical cam 
portions formed on each respective operation rod of the switch. A second 
switch block is disposed generally parallel to the first switch block and 
includes a second frame member and a plurality of second push-button 
switches supported by the second frame member and also having a pair of 
symmetrical cam portions formed on their operation rods. Means are 
provided for connecting the first and second frames to each other, and a 
latch member having a plurality of cam parts symmetrical with respect to 
the axis of the latch member and movable in response to the movements of 
the operation rods of the first or second switch are disposed between the 
first and second switch blocks so that one of these cam parts is engaged 
with the corresponding cam portion of the operation rod for the first 
switch with the other thereof engaged with the corresponding cam portion 
of the operation rod for the second switch, and urged in one direction by 
a spring means. 
The above and other objects, as well as advantageous features of the 
invention will become apparent from the following description of the 
preferred embodiments taken in conjunction with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Before turning to the description of the preferred embodiments, a known 
interlocking ganged push-button switch will be described in detail with 
reference to the accompanying drawings. 
The switch of FIG. 1 includes a box member 1 made from an electrically 
insulating material such as a synthetic resin, onto which is fixed an 
insulating base plate 2 having a plurality of stationary terminals 3 
extending vertically therethrough. In the box member 1, an operation rod 4 
also made of an electrically insulating material such as a synthetic resin 
is slidably fitted. The operation rod 4 is shown in FIG. 4 and has 
recesses 5, into which movable contact members (not shown) are to be 
fitted, and an interlocking cam portion 6. As shown in FIG. 2, a stopping 
member 8 is fitted in grooves 7, and a spring 9 is disposed between the 
stopping member 8 and the front surface of a support 10 to return the 
operation rod 4 to its original position. A plurality of push-button 
switches A thus formed are arranged in and secured to the substantially 
cross-sectionally U-shaped metallic support 10 as shown in FIGS. 1 and 2, 
so that the cam portions 6 of the operation rods 4 are within the support 
10 as shown in FIGS. 2 and 3. 
An interlocking latch member 11 having a plurality of cam parts 12 is 
disposed so that the cam parts 12 are engageable with and disengageable 
from the interlocking cam portions 6 of the operation rod 4, and a spring 
13 is disposed between the base portion of an engagement member 12a 
projected from a cam part 12 and the push-button switch A to return the 
latch member 11 to its original position. Thus, a switch block B is 
formed, in which the push-button switches A are interlocked with one 
another. 
The ends of the supports 10 for the two switch blocks B.sub.1, B.sub.2 are 
connected to each other with connector members 14 so that these switch 
block B.sub.1, B.sub.2 are opposed to each other and integrally fixed as 
shown in FIG. 5. In order to interlock the push-button switches A in these 
switch blocks B.sub.1, B.sub.2, connecting means 15 which are pivotally 
connected to supporting shafts (not shown) provided in the connector 
members 14, are disposed at the end portions of the interlocking cam plate 
11, as shown in FIG. 6, so that the latch members 11 are interlocked with 
each other. When desired operation rods 4 in the switch blocks B.sub.1, 
B.sub.2 are depressed, the push-button switches in these switch blocks 
B.sub.1, B.sub.2 are interlocked with each other. A more detailed 
description of the above known device can be found in U.S. patent 
application Ser. No. 758,592 filed Jan. 12, 1977 and resulting in U.S. 
Pat. No. 4,122,316 on Oct. 24, 1978. 
Now, an embodiment of the present invention will be described with 
reference to FIGS. 7-12, in which the same parts as in the interlocking 
ganged push-button switch as shown in FIGS. 1-6 are designated by the same 
reference numerals. 
Reference numeral 16 denotes an operation rod slidably fitted in a box 
member 1 of each push-button switch A'. The operation rod 16 is provided 
in one surface thereof with recesses 17 into which movable contact members 
(not shown) are to be fitted. In the opposing surface of the operation rod 
16, a pair of symmetrical cam portions 18 and 19 are formed, and these cam 
portions have respective inclined portions 18a or 19a, peak portions 18b 
or 19b, valley portions 18c or 19c, and engagement portions 18d or 19d. 
Reference numeral 20 denotes grooves into which a stopping member 8 can be 
fitted. 
A plurality of push-button switches A' fitted with the operation rods 16 
are mounted on a support 10. In the push-button switches A', a row of 
stationary terminals 3 are secured to and extend outwardly from the lower 
surface of a box member 1, which lower surface is opposite to the open 
side of the support 10 as shown in FIGS. 8 and 9. This, of course, is 
directly opposite to the interlocking ganged push-button switch as shown 
in FIGS. 1-6, wherein the stationary terminals are secured to the upper 
surface of support 10. Switch blocks B.sub.1, B.sub.2 are thus formed. The 
switch blocks B.sub.1, B.sub.2 are disposed with the open sides of the 
respective supports 10 opposed to one another, and connecting members 24 
are secured to ends of the supports 10. Thus, the switch blocks B.sub.1, 
B.sub.2 are integrally fixed by a suitable means as shown in FIGS. 10, 11. 
A metallic interlocking latch member 21 has a plurality of symmetrical cam 
parts 22 along the longitudinal sides thereof and slide portions 23 at 
each end thereof, as shown in FIG. 12. The slide portions 23 are each 
slidably fitted in and supported by a respective recesses 25 provided in 
the connecting members 24. Each cam part 22 enters a groove 1a (see FIG. 
8) provided in the front portion of the box member 1 of push-button 
switches A' so that the cam part 22 contacts the cam portion 18 or 19 of 
the operation rods 16 in switch blocks B.sub.1, B.sub.2. A spring 26 is 
provided to thereby return the interlocking latch member 21, as shown in 
FIG. 11. As shown in FIGS. 11 and 9, one end of the spring 26 is fitted on 
an engagement member 22a projecting from a cam part 22 of the latch member 
21, while the base end thereof is secured to the front surface of the box 
member 1 of an adjacent push-button switch A', so that the spring 26 
always urges the latch member 21 in the direction P of FIG. 11. By the 
urging force of the spring 26, the cam parts 22 at the upper side, in the 
drawings, of the latch member 21 come into contact with the cam portions 
18 of the operation rods 16 in the switch block B.sub.1, while the lower 
cam parts 22 come into contact with the cam portions 19 of the operation 
rods 16 in the switch block B.sub.2. When the switch is not operated, the 
cam parts 22 at both sides of the latch member 21 are in contact with the 
inclined portions 18a or 19a of the cam portions 18 and 19, respectively. 
The operation of the switch constructed as described above of an embodiment 
of the present invention will be described with reference to FIGS. 9 and 
11. 
When a desired operation rod 16 in the switch block B.sub.1 is depressed 
against the resilient force of the spring 9, the inclined portion 18a of 
that operation rod operates against the associated cam part 22 to move the 
latch member 21 in the direction X as shown in FIGS. 9 and 11, and 
compresses the spring 26. When, during this movement of the interlocking 
cam plate 21, the cam parts 22 have passed the peak portions 18b of the 
cam portions 18 of the operation rod, the cam parts 22 are urged into the 
valley portions 18c by the resilient force of the spring 26. At the same 
time, the interlocking latch member 21 moves in the direction P, as shown 
in FIGS. 9 and 11, and returns to its original position, while the 
movement of the operation rod 16 is stopped with the rear end thereof 
contacting the back of the box member 1. When the operation rod 16 is then 
released, the engagement portions 18d engage with the associate cam part 
22 so that the operation rod 16 is not returned to its original position 
but locked as it is. (At this time, the switch is changed over.) When a 
desired operation rod 16 in the switch block B.sub.2 is then depressed, 
the inclined portion 19a of this rod urges the associated cam part 22 so 
as to move the interlocking latch member 21 in the direction of the arrow 
X. Thus, the interlocking latch member 21 will come to be locked in the 
same manner as mentioned above. When the interlocking latch member 21 is 
thus moved, any operation rod 16 which has been previously locked is 
released as the engagement portions 18d thereof are disengaged from the 
associate cam part 22 by a movement of the latch member 21. When another 
operation rod 16 in the switch blocks B.sub.1 or B.sub.2 is then 
depressed, it is locked in the same manner as mentioned above and, at the 
same time, any operation rod 16 which has been locked is released. In the 
switch of this embodiment, each of the operation rods 16 in the switch 
blocks B.sub.1 and B.sub.2 is interlocked with every other operation rod 
by a single interlocking latch member 21. 
In the interlocking ganged push-button switch of the present invention, 
each of the operation rods 16 in the switch blocks B.sub.1 and B.sub.2 is 
interlocked by a single interlocking latch member 21 owing to the pair of 
symmetrical cam portions 18 and 19 of the operation rods 16. Thus, unlike 
the prior art interlocking ganged push-button switch, connecting members 
such as those shown as elements 15 in FIG. 6 are not needed in the switch 
of the present invention. Consequently, the interlocking push-button 
switch of the present invention has a more simple construction and can be 
miniaturized and assembled easily. The strokes of the interlocking cam 
plate 21 in the switch of the present invention can be easily determined 
and this allows the switch to be accurately and smoothly operated as well 
as the productivity and performance thereof to be improved. 
FIG. 13 shows another embodiment of an operation rod which has a conical 
cam 35 instead of the two cam portions of the embodiment as described 
above. Referring to the FIG. 13, reference numeral 35a denotes an inclined 
portion, 35b a peak portion, 35c a valley portion, and 35d an engagement 
portion. This cam has the same operation as the cam portions 18 and 19 of 
the operation rod 16 in the embodiment described previously. 
FIGS. 14 and 15 show another embodiment of the interlocking push-button 
switch provided with an interlocking mechanism of the present invention. 
In FIGS. 14 and 15, the parts designated by the same reference numerals as 
those used in FIGS. 10 and 11 are the same ones as those shown in FIGS. 10 
and 11. A plurality of push-button switches A' are arranged in two rows to 
oppose one another. A front plate 40 and a rear plate 41 are attached to 
the front and rear surfaces, respectively, of two adjacent switches, and a 
screw rod 42 is passed through holes (not shown) in these plates 40 and 
41. The screw rod 42 can then be tightened by means of a nut 43 fitted on 
a portion thereof that projects beyond the rear plate 41. Thus, the 
push-button switches A' are integrally fixed so that a plurality of cam 
parts 45 formed along the longitudinal sides of an interlocking latch 
member 44 are engageable with and disengageable from cam portions (not 
shown) of operation rods 16 in the push-button switches A' in each row in 
the same manner as in the previously-described embodiment of the present 
invention. In addition, springs 47 for returning the interlocking cam 
plate 44 to its initial position are provided in respective rectangular 
openings 46 in the latch member, and are supported by a respective edge 
portion of the openings 46 and respective screw rods 42. This push-button 
switch has an operation similiar to that of the previously-described 
embodiment.