Key switch having elastic portions for facilitating attachment of scissors-type support linkage to keytop and holder, and removal of keytop from linkage

A key switch comprising:

• a keytop;
• a holder spaced apart from and opposed to said keytop;
• a support linkage for connecting said keytop and said holder such that said keytop is movably supported and guided by said support linkage, said support linkage including a first link and a second link which are connected to each other in the form of scissors pivotally about a common primary pivot shaft, each of opposite end portions of each of said first and second links having one of a secondary pivot shaft and a bearing portion, while each of four portions of said keytop and said holder which correspond to said opposite end portions of said first and second links having the other of said secondary pivot shaft and said bearing portion, said bearing portion supporting said secondary pivot shaft at least pivotally about an axis of said secondary pivot shaft;
• a switching portion operated by movements of said keytop to effect a switching action;
• said secondary pivot shafts including at least one special secondary pivot shaft which is carried by a special support portion, and said bearing portions including at least one special bearing portion which engages said at least one special secondary pivot shaft;
• and
• at least one of said special support portion and the corresponding special bearing portion including an elastic portion which elastically yields to allow engagement of said special secondary pivot shaft and said special bearing portion when said keytop is moved toward said holder with said support linkage being interposed between said keytop and said holder before the engagement of said special secondary pivot shaft and said special bearing portion,
• wherein said first link is generally U-shaped and includes a pair of first arm portions and a first connecting portion, which connects said first arm portions at corresponding fixed ends thereof such that said first arm portions are parallel to each other, and wherein said second link is generally H-shaped and includes a pair of second arm portions and a second connecting portion, which connects said second arm portions at least at middle parts thereof such that said second arm portions are parallel to each other,
• and wherein one of said pairs of first and second arm portions has a pair of bosses while the other of said pairs of first and second arm portions has a pair of holes, said first and second links being connected pivotally relative to each other such that said second arm portions are disposed inside said first arm portions and such that said pair of bosses engage said pair of holes so as to provide said common primary pivot shaft.

A key switch comprising:

• a keytop;
• a holder spaced apart from and opposed to said keytop;
• a support linkage for connecting said keytop and said holder such that said keytop is movably supported and guided by said support linkage, said support linkage including a first link and a second link which are connected to each other in the form of scissors pivotally about a common primary pivot shaft, each of opposite end portions of each of said first and second links having one of a secondary pivot shaft and a bearing portion, while each of four portions of said keytop and said holder which correspond to said opposite end portions of said first and second links having the other of said secondary pivot shaft and said bearing portion, said bearing portion supporting said secondary pivot shaft at least pivotally about an axis of said secondary pivot shaft;
• a switching portion operated by movements of said keytop to effect a switching action;
• said secondary pivot shafts including at least one special secondary pivot shaft which is carried by a special support portion, and said bearing portions including at least one special bearing portion which engages said at least one special secondary pivot shaft;
• and
• at least one of said special support portion and the corresponding special bearing portion including an elastic portion which elastically yields to allow engagement of said special secondary pivot shaft and said special bearing portion when said keytop is moved toward said holder with said support linkage being interposed between said keytop and said holder before the engagement of said special secondary pivot shaft and said special bearing portion,
• wherein one of said first and second links has an abutting portion which is abuttable against the other of said first and second links so as to limit an amount of relative pivotal movement of said first and second links in a direction that permits said keytop and said holder to move toward each other.

A key switch comprising:

• a keytop;
• a holder spaced apart from and opposed to said keytop;
• a support linkage for connecting said keytop and said holder such that said keytop is movably supported and guided by said support linkage, said support linkage including a first link and a second link which are connected to each other in the form of scissors pivotally about a common primary pivot shaft, each of opposite end portions of each of said first and second links having one of a secondary pivot shaft and a bearing portion, while each of four portions of said keytop and said holder which correspond to said opposite end portions of said first and second links having the other of said secondary pivot shaft and said bearing portion, said bearing portion supporting said secondary pivot shaft at least pivotally about an axis of said secondary pivot shaft;
• a switching portion operated by movements of said keytop to effect a switching action;
• said secondary pivot shafts including at least one special secondary pivot shaft which is carried by a special support portion, and said bearing portions including at least one special bearing portion which engages said at least one special secondary pivot shaft;
• and
• at least one of said special support portion and the corresponding special bearing portion including an elastic portion which elastically yields to allow engagement of said special secondary pivot shaft and said special bearing portion when said keytop is moved toward said holder with said support linkage being interposed between said keytop and said holder before the engagement of said special secondary pivot shaft and said special bearing portion,
• wherein said first link includes a pair of first arm portions and a first connecting portion, which connects said first arm portions at corresponding fixed ends thereof, and said second link includes a pair of second arm portions and a second connecting portion, which connects said second arm portions at least at middle parts thereof,
• wherein at least one of said pair of second arm portions of said second link has an abutting portion which is abuttable against at least one of said pair of first arm portions of said first link so as to limit an amount of relative pivotal movement of said first and second links in a direction that permits said keytop and said holder to move toward each other, said abutting portion being formed at an end of said at least one second arm portion which is moved toward a free end of said first link remote from said fixed end when said keytop is moved toward said holder, said abutting portion extending from said at least one second arm portion in a direction parallel to an axis of said common primary pivot shaft and outwardly of said second link.

A key switch comprising:

• a keytop;
• a holder spaced apart from and opposed to said keytop;
• a support linkage for connecting said keytop and said holder such that said keytop is movably supported and guided by said support linkage, said support linkage including a first link and a second link which are connected to each other in the form of scissors pivotally about a common primary pivot shaft, each of opposite end portions of each of said first and second links having one of a secondary pivot shaft and a bearing portion, while each of four portions of said keytop and said holder which correspond to said opposite end portions of said first and second links having the other of said secondary pivot shaft and said bearing portion, said bearing portion supporting said secondary pivot shaft at least pivotally about an axis of said secondary pivot shaft;
• a switching portion operated by movements of said keytop to effect a switching action;
• said secondary pivot shafts including at least one special secondary pivot shaft which is carried by a special support portion, and said bearing portions including at least one special bearing portion which engages said at least one special secondary pivot shaft;
• and
• at least one of said special support portion and the corresponding special bearing portion including an elastic portion which elastically yields to allow engagement of said special secondary pivot shaft and said special bearing portion when said keytop is moved toward said holder with said support linkage being interposed between said keytop and said holder before the engagement of said special secondary pivot shaft and said special bearing portion,
• wherein removal facilitating means is provided for facilitating removal of said keytop from said support linkage prior to removal of said support linkage from said holder when a force is applied to said keytop in a direction away from said holder after said first and second links are connected to said keytop and said holder.

A key switch comprising:

• a keytop;
• a holder spaced apart from and opposed to said keytop;
• a support linkage for connecting said keytop and said holder such that said keytop is movably supported and guided by said support linkage, said support linkage including a first link and a second link which are connected to each other in the form of scissors pivotally about a common primary pivot shaft, each of opposite end portions of each of said first and second links having one of a secondary pivot shaft and a bearing portion, while each of four portions of said keytop and said holder which correspond to said opposite end portions of said first and second links having the other of said secondary pivot shaft and said bearing portion, said bearing portion supporting said secondary pivot shaft at least pivotally about an axis of said secondary pivot shaft;
• a switching portion operated by movements of said keytop to effect a switching action;
• said secondary pivot shafts including at least one special secondary pivot shaft which is carried by a special support portion, and said bearing portions including at least one special bearing portion which engages said at least one special secondary pivot shaft;
• and
• at least one of said special support portion and the corresponding special bearing portion including an elastic portion which elastically yields to allow engagement of said special secondary pivot shaft and said special bearing portion when said keytop is moved toward said holder with said support linkage being interposed between said keytop and said holder before the engagement of said special secondary pivot shaft and said special bearing portion,
• wherein each of said opposite ends of said first and second links has said secondary pivot shaft, and wherein the bearing portion which engages the corresponding secondary pivot shaft provided at one of said opposite ends of each of said first and second links consists of a sliding type bearing portion which supports said corresponding secondary pivot shaft pivotally and slidably movably in a direction substantially perpendicular to a direction of movements of said keytop, and wherein the bearing portion which engages the corresponding secondary pivot shaft provided at the other of said opposite ends of said each of said first and second links consists of a non-sliding type bearing portion which supports said corresponding secondary pivot shaft pivotally and so as to prevent sliding movements of said corresponding secondary pivot shaft in said direction substantially perpendicular to the direction of movement of the keytop.

A key switch comprising:

• a keytop;
• a holder spaced apart from and opposed to said keytop;
• a support linkage for connecting said keytop and said holder such that said keytop is movably supported and guided by said support linkage, said support linkage including a first link and a second link which are connected to each other in the form of scissors pivotally about a common primary pivot shaft, each of opposite end portions of each of said first and second links having one of a secondary pivot shaft and a bearing portion, while each of four portions of said keytop and said holder which correspond to said opposite end portions of said first and second links having the other of said secondary pivot shaft and said bearing portion, said bearing portion supporting said secondary pivot shaft at least pivotally about an axis of said secondary pivot shaft;
• a switching portion operated by movements of said keytop to effect a switching action;
• said secondary pivot shafts including at least one special secondary pivot shaft which is carried by a special support portion, and said bearing portions including at least one special bearing portion which engages said at least one special secondary pivot shaft;
• and
• at least one of said special support portion and the corresponding special bearing portion including an elastic portion which elastically yields to allow engagement of said special secondary pivot shaft and said special bearing portion when said keytop is moved toward said holder with said support linkage being interposed between said keytop and said holder before the engagement of said special secondary pivot shaft and said special bearing portion,
• wherein the secondary pivot shafts for connecting one of the opposite ends of each of said first and second links to said keytop and the secondary pivot shafts for connecting the other of the opposite ends of each of said first and second links to said holder include at least one secondary pivot shaft which is formed on one of said keytop and said holder and which engages at least one bearing portion formed on one of said first link and said second link.