Keyswitch for computer keyboards

A keyswitch is provided that comprises a key top, a rubber cone, a first lever, a second lever, and a base. An operation surface and an assembly surface respectively form at the top end and the bottom end of the key top. A penetrating accommodation room is installed on the base. The rubber cone is installed between the key top and the base. The first lever and the second lever are installed between the assembly surface of the key top and the base. The two levers are in scissors arrangement. The top ends of the two levers are connected to the assembly surface of the key top. The bottom ends of the two levers are connected to the base. The accommodation room is disposed below the two levers. A bottom board is installed at the bottom of the base. When the two levers are jointly moved downwards via the key top, they can sink into the accommodation room. A low-profile keyswitch can be acquired under the condition of the same key pressing stroke. The compactness requirement of modern products can thus be achieved.

FIELD OF THE INVENTION 
The present invention relates to a keyswitch for computer keyboards, 
especially to a low-profile keyswitch that fits the compactness 
requirement of modern products, and thus is suitable for keyboards of 
notebook computers. 
BACKGROUND OF THE INVENTION 
As shown in FIG. 1, the conventional keyswitch 10 of computer keyboards 
comprises a key top 11a, a rubber cone 12a, a first lever 13a, a second 
lever 14a, a base 16a, and a bottom board 22a. The first lever 13a and the 
second lever 14a are in scissors arrangement. Shafts 18a and 19a at the 
bottom ends of the first lever 13a and the second lever 14a are 
respectively pivotally arranged within pivotal grooves 20a and 21a 
installed at the top of the base 16a. The top ends of the first lever 13a 
and the second lever 14a are connected to the key top 11a. The first lever 
13a and the second lever 14a form a jointly moving mechanism. The rubber 
cone 12a is disposed within the key pressing stroke of the key top 11a. 
When the key top 11a is guided to move upwards or downwards via the two 
levers 13a and 14a, the rubber cone 12a can press or leave a membrane 
circuit 15a to let a switch be on or off. However, the keyswitch 10a, the 
base 16a, the first lever 13a, and the second lever 14a all have a certain 
thickness such that the total height of the keyswitch 10a is increased. 
The compactness requirement of modern products can not be achieved. 
SUMMARY AND OBJECTS OF THE PRESENT INVENTION 
Accordingly, the primary object of the present invention is to provide a 
keyswitch comprising a key top, a rubber cone, a first lever, a second 
lever, and a base, which is characterized in that a penetrating 
accommodation room is installed on the base. The accommodation room is 
disposed below the first and the second levers. When the two levers are 
jointly moved downwards via the key top, they can sink into the 
accommodation room. A low-profile keyswitch can be acquired under the 
condition of the same key pressing stroke. The compactness requirement of 
modern products can thus be achieved. 
The various objects and advantages of the present invention will be more 
readily understood from the following detailed description when read in 
conjunction with the appended drawing, in which:

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
As shown in FIGS. 2 to 4, a keyswitch 10 of the present invention comprises 
a key top 11, a rubber cone 12, a first lever 13, a second lever 14, and a 
base 15. The key top is a generally quadratic cap with an operation 
surface 16 and an assembly surface 17 formed respectively at the top end 
and the bottom end thereof. Two pivotal holes 18 and two slide grooves 19 
are disposed on the assembly surface 17. 
The first lever 13 and the second lever 14 are installed between the 
assembly surface 17 of the key top 11 and the base 15. Corresponding 
shafts 20 and pivotal holes 21 are respectively installed at the central 
part of two sides of the first lever 13 and the second lever 14 to let 
them be pivotally in scissors arrangement and form a jointly-moving 
mechanism. 
The rubber cone 12 is installed between the key top 11 and the base 15. The 
rubber cone 12 is disposed within the key pressing stroke of the key top 
11. A shaft 22 is installed at the top end of each side of the first lever 
13. A slide shaft 23 is installed at the top end of each side of the 
second lever 14. The first lever 13 is pivotally arranged within the 
pivotal holes 18 of the key top 11 via the shafts 22 at the top ends of 
both sides thereof. The second lever 14 is slidably matched to the slide 
groove 19 of the key top 11 via the slide shafts 23 at the top ends of 
both sides thereof. The top ends of the first lever 13 and the second 
lever 14 are thus connected to the assembly surface 17 of the key top 11. 
Shafts 24 and 25 respectively installed at the bottom ends of the first 
lever 13 and the second lever 14 are pivotally arranged within holes 26 
and 27 of the base 15. Positioning plates 28 and 29 are respectively 
installed above the holes 26 and 27 to limit upward movement of the shafts 
24 and 25. A membrane circuit and a bottom board 31 are installed at the 
bottom of the base 15. Holes 33 and 34 corresponding to the shafts 24 and 
25 are respectively disposed at the membrane circuit 30 and the bottom 
board 31. When the key top 11 is guided to move upwards and downwards via 
the two levers 13 and 14, the rubber cone 12 below the key top 11 can 
press or leave the membrane circuit 30 to let a switch be on or off. 
The present invention is characterized in that a penetrating accommodation 
room 32 is installed on the base 15. The accommodation room 32 is disposed 
below the first lever 13 and the second lever 14 to accommodate them. When 
the two levers 13 and 14 are jointly moved downwards by the key top 11, 
they can sink in the accommodation room 32. The thickness of the keyswitch 
10 can be reduced under the condition of the same key pressing stroke. A 
low-profile keyswitch can be acquired such that the compactness 
requirement of modern products are achieved. Moreover, the first lever 13 
and the second lever 14 can be assembled from below except from above the 
base 15, resulting in easier assembly and lower cost. 
Although the present invention has been described with reference to the 
preferred embodiment thereof, it will be understood that the invention is 
not limited to the details thereof. Various substitutions and 
modifications have suggested in the foregoing description, and other will 
occur to those of ordinary skill in the art. Therefore, all such 
substitutions and modifications are intended to be embraced within the 
scope of the invention as defined in the appended claims.