Background of the Invention
1. Field of the Invention
The invention relates to a computer key, more particularly to a computer key with a push button which includes a retention groove defining portion of a novel structure at an under side thereof to provide a stable hing-type engagement to hooking ends of a respective pair of two pairs of pivotally connected linking arms that are disposed between a base plate and the push button.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional computer key is shown to include a base plate 40, a membrane circuit 60, a push button 11, an upright elastomeric biasing member 50, and a linking frame member 12 consisting of first and second linking frames 121, 122.
As illustrated, the base plate 40 includes a first hingeably retaining groove 401 which defines a first hinging axis, and a first slidably retaining guideway 402 spaced apart from the first hingeably retaining groove 401 in a longitudinal direction of the base plate 40 so as to define an actuation area 403 therebetween. The first hinging axis is transverse to the longitudinal direction.
The membrane circuit 60 is disposed in the actuation area 403.
The biasing member 50 includes an upper depressing portion 501 and a spacing lower portion 502 to space the upper depressing portion 501 from the actuation area and to depress the actuation area as well as a contact area of the membrane circuit 60 so as to generate an electrical signal.
The push button 11 is disposed to actuate the depressing portion 501 of the biasing member 50, and has a second hingeably retaining groove 112 that defines a second hinging axis and a second slidably retaining guideway 113 disposed in an underside thereof. The second hingeably retaining groove 112 and the second slidably retaining guideway 113 are in diagonal positions relative to the first slidably retaining guideway 402 and the first hingeably retaining groove 401 of the base plate 10, respectively.
The first linking frame 121 includes a pair of first linking arms 1211 that extend respectively in a first transverse direction relative to the first hinging axis, a first bracing member 1214 disposed between the first linking arms 1211 to space apart the same in the direction of the first hinging axis, first front and rear hooking ends 1212, 1213 which extend respectively from the first linking arms 1211 away from each other and in the same direction of the first hinging axis so as to be retained hingeably in the first hingeably retaining groove 401, and a pair of first hooking fingers 1215 which extend respectively from the first linking arms 1211 parallel to either of the first front and rear hooking ends 1212, 1213. The first hooking fingers 1215 are fitted to and are slidably retained in the second slidably retaining guideway 113.
The second linking frame 122 includes a pair of second linking arms 1221 extend respectively in a second transverse direction relative to the second hinging axis, a second bracing member 1224 disposed between the second linking arms 1221 to space apart the sane in the direction of the second hinging axis, a transverse axle 1222 interposed between the second linking arms 1221 in the direction of the second hinging axis so as to be fitted and retained hingeably in the second hingeably retaining groove 112, and a pair of second hooking fingers 1223 which extend respectively from the second linking arms 1221 parallel to the transverse axle 1222. The second hooking fingers 1223 are fitted to and are slidably retained in the first slidably retaining guideway 402.
During assembly, the first and second linking arms 1211, 1221 are pivotally connected to each other at intermediate portions thereof. Then, the front and rear hooking ends 1212, 1213 and the second hooking fingers 1223 of the first and second linking arms 1211, 1221 are inserted in the first hinegably retaining groove 401 and the first slidably retaining guideway 402 of the base plate 40 so as to be retained therein. The push button 11 is disposed on the first and second linking arms 1211, 1221 in such a manner that the transverse axle 1222 is aligned with the second hingeably retaining groove 112. A downward pressure applied on the push button 11 will force the transverse axle 1222 through a constricted gap 112a of the second hingeably retaining groove 112 so as to engage the transverse axle 1222 in the latter. At this time, the first hooking fingers 1215 expand outwardly away from each other in the second hinging axis so as to slip into the second slidably retaining guideway 113 of the push button 11.
It is noted that, when the downward pressure applied on the push button 11 is offset relative to the center, such as on the peripheral section of the push button 11, thereby creating an inclined pressure on the transverse axle 1222, the transverse axle 1222 will be forced to slip out of the constricted gap 112a and disengage the second hingeably retaining groove 112.
Summary of the Invention
Therefore, the object of this invention is to provide a computer key which includes a push button with a retention groove defining portion of a unique structure to provide a stable hing-type engagement to hooking ends of a respective pair of two pairs of pivotally connected linking arms that are disposed between a base plate and the push button.
Accordingly, the computer key of this invention includes a base plate, a membrane circuit, an upright elastomeric biasing member, a push button, and a pair of pivotally connected frames consisting of first and second linking frames. The base plate includes a first hingeably retaining groove that defines a first hinging axis, and a first slidably retaining guideway spaced apart from the first hingeably retaining groove in a longitudinal direction of the base plate to define an actuation area therebetween. The first hinging axis is transverse to the longitudinal direction. The membrane circuit is disposed in the actuation area to form a contact area thereon. The upright elastomeric biasing member includes an upper depressing portion and a spacing lower portion to space the upper depressing portion from the actuation area to depress the actuation area as well as the contact area of the membrane circuit so as to generate an electrical signal. The push button is disposed to actuate the depressing portion of the biasing member, and has a hingeably retention groove defining portion that defines a second hinging axis transverse to the longitudinal direction, and a second slidably retaining guideway which are disposed in an underside thereof in diagonal positions relative to the first slidably retaining guideway and the first hingeably retaining groove of the base plate, respectively.
The first linking frame includes a pair of first linking arms 311 that extend respectively in a first transverse direction relative to the first hinging axis, a first bracing member disposed between the first linking arms to space apart the first linking arms in the direction of the first hinging axis, first front and rear hooking ends which extend respectively from the first linking arms away from each other and in the direction of the first hinging axis so as to be retained hingeably in the first hingeably retaining groove, and a pair of first hooking fingers which extend respectively from the first linking arms and parallel to either of the first front and rear hooking ends. The first hooking fingers are fitted to and are slidably retained in the second slidably retaining guideway.
The second linking frame includes a pair of second linking arms 321 that extend respectively in a second transverse direction relative to the second hinging axis, a second bracing member disposed between the second linking arms to space apart the same in the direction of the second hinging axis, second front and rear hooking ends extending respectively from the second linking arms in the direction of the second hinging axis and toward each other to define a first spaced distance therebetween, the second front and rear hooking ends being fitted and retained hingeably in the hingeably retention groove defining portion, and a pair of second hooking fingers extending respectively from the second linking arms and parallel to either of the second front and rear hooking ends. The second hooking fingers are fitted to and are slidably retained in the first slidably retaining guideway. The first and second linking arms are pivotally connected to each other at intermediate portions thereof such that the first and second linking arms confine a space to accommodate depressing movement of the biasing member when the first front and rear hooking ends, the first hooking fingers, the second front and rear hooking ends, and the second hooking fingers are received in the first hingeably retaining groove, the second slidably retaining guideway, the hingeably retention groove defining portion and the first slidably retaining guideway, respectively.
The retention groove defining portion of the push button includes front and rear bearing support members which are spaced apart from each other along the second hinging axis. The front and rear bearing support members have front and rear outboard walls in the second hinging axis. The front and rear outboard walls cooperate to define a second spaced distance which is larger than the first spaced distance. The front and rear outboard walls have front and rear recesses respectively so as to form front and rear bearing surfaces respectively transverse to the front and rear outboard walls and facing upwardly toward the underside of the push button. When the second front and rear hooking ends are to be fitted into the hingeably retention groove defining portion, they are initially forced apart along the second hinging axis, thereby permitting press fitting thereof into the front and rear recesses by slipping on the front and rear outboard walls respectively so that the second front and rear hooking ends are hingeably retained on the front and rear bearing surfaces, respectively.
Brief Description of the Drawings
Other features and advantages of this invention will become more apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, in which:
FIG. 1 is a sectional view of a conventional computer key;
FIG. 2 is a perspective view of a linking frame member employed in the conventional computer key of FIG. 1;
FIG. 3 is a sectional view of a preferred embodiment of a computer key according to this invention;
FIG. 4 is a perspective view of a push button and a linking frame member employed in the preferred embodiment;
FIG. 5 is a sectional view of the push button of the preferred embodiment taken along line V--V of FIG. 4;
FIG. 6 is a sectional view of the push button of the preferred embodiment taken along line VI--VI of FIG. 4; and
FIG. 7 illustrates how two linking frames of the frame member shown in FIG. 4 are connected pivotally to each other before attachment between a base plate and the push button of the preferred embodiment.
Detailed Description of the Preferred Embodiment
Referring to FIGS. 3 and 4, the preferred embodiment of a computer key according to this invention is shown to include a base plate 10, a membrane circuit 600, an upright elastomeric biasing member 500, a push button 20, and a linking frame pair consisting of first and second linking frames 31, 32.
As illustrated, the base plate 10 includes a first hingeably retaining groove 101 that defines a first hinging axis, and a first slidably retaining guideway 102 that is spaced apart from the first hingeably retaining groove 101 in a longitudinal direction of the base plate 10 so as to define an actuation area 105 therebetween. The first hinging axis is transverse to the longitudinal direction.
The membrane circuit 600 is disposed in the actuation area 105 to form a contact area thereon.
The biasing member 500 includes an upper depressing portion 501 and a spacing lower portion 502 to space the upper depressing portion 501 from the actuation area 105 to depress the actuation area 105 as well as the contact area of the membrane circuit 600 so as to generate an electrical signal.
As shown in FIGS. 3, 5 and 6, the push button 20 is disposed to actuate the depressing portion 501 of the biasing member 50, and has a hingeably retention groove defining portion 22 that defines a second hinging axis transverse to the longitudinal direction, and a second slidably retaining guideway 23 disposed in an underside thereof in diagonal positions relative to the first slidably retaining guideway 102 and the first hingeably retaining groove 101 of the base plate 10, respectively.
The first linking frame 31 includes a pair of first linking arms 311 that extend respectively in a first transverse direction relative to the first hinging axis, a first bracing member 312 disposed between the first linking arms 311 to space apart the same in the direction of the first hinging axis, first front and rear hooking ends 313, 314 extending respectively from the first linking arms 311 away from each other and in the same direction of the first hinging axis so as to be retained hingeably in the first hingeably retaining groove 101, and a pair of first hooking fingers 315 that extend respectively from the first linking arms 311 and parallel to either of the first front and rear hooking ends 313, 314. The first hooking fingers 315 are fitted to and are slidably retained in the second slidably retaining guideway 23 of the push button 20.
The second linking frame 32 includes a pair of second linking arms 321 that extend respectively in a second transverse direction relative to the second hinging axis, a second bracing member 322 disposed between the second linking arms 321 to space apart the same in the direction of the second hinging axis, second front and rear hooking ends 323, 324 which extend respectively from the second linking arms 321 in the direction of the second hinging axis and toward each other to define a first spaced distance therebetween, the second front and rear hooking ends 323, 324 being fitted and retained hingeably in the hingeably retention groove defining portion 22, and a pair of second hooking fingers 325 that extend respectively from the second linking arms 321 and parallel to either of the second front and rear hooking ends 323, 324. The second hooking fingers 325 are fitted to and are slidably retained in the first slidably retaining guideway 102 of the base plate 10.
Referring to FIG. 7, the first and second linking arms 311, 321 are pivotally connected to each other at intermediate portions thereof such that the first and second linking arms 311, 321 confine a space to accommodate depressing movement of the biasing member 500 (see FIG. 3) when the first front and rear hooking ends 313, 314, the first hooking fingers 315, the second front and rear hooking ends 323, 324, and the second hooking fingers 325 are received in the first hingeably retaining groove 101, the second slidably retaining guideway 23, the hingeably retention groove defining portion 22 (see FIG. 3) and the first slidably retaining guideway 102 (see FIG. 3), respectively.
Referring again to FIG. 4, the hingeably retention groove defining portion 22 of the push button 20 includes front and rear bearing support members 222 that are spaced apart from each other along the second hinging axis. The front and rear bearing support members 222 have front and rear outboard walls 224 in the second hinging axis and define a second spaced distance larger than the first spaced distance. The front and rear outboard walls 224 have front and rear recesses 221 so as to form front and rear bearing surfaces 221A. The front and rear bearing surfaces 221A are transverse to the front and rear outboard walls 224 respectively and face upwardly toward the underside of the push button 20. When the second front and rear hooking ends 323, 324 of the second linking arms 321 are to be fitted into the hingeably retention groove defining portion 22, they are initially forced apart in the second hinging axis, thereby permitting press fitting of the hooking ends 323, 324 into the front and rear recesses 221 by slipping on the front and rear outboard walls 224 respectively so that the second front and rear hooking ends 323, 324 are hingeably retained on the front and rear bearing surfaces 221A respectively.
The front and rear bearing support members 222 respectively have front and rear bottom walls 225 that are parallel to the second hinging axis and that cooperate with the front and rear outboard walls 224 to form front and rear joining edge portions 225A, respectively. The front and rear joining edge portions 225A are rounded so as to facilitate slipping of a respective one of the second front and rear hooking ends 323, 324 into a corresponding one of the front and rear recesses 221.
Each of the front and rear recesses 221 includes a proximate wall portion 221C relative to the second slidably retaining guideway 23 and a distal wall portion 221B which are transverse to a respective one of the front and rear bearing surfaces 221A to define a respective one of the front and rear recesses 221. Each of the front and rear bearing support members 222 further includes a guide-in block member 223 that extends from and beyond the distal wall portion 221B in the second hinging axis so as to define an abutment wall 223A to further facilitate slipping of the second front and rear hooking ends 323, 324 into the front and rear recesses 221.
While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.