Abstract: A foldable transformer comprises an insulative enclosure (2) and a plug (16) rotatably attached to the enclosure. The enclosure includes a storage cavity (4), a pair of pin holes (14), and a pair of parallel slots (12). An arcuate engaging block (8) is formed on a bridge (10) between the slots. The plug includes a transverse rod (18), a pair of rotary pins (22), and a pair of fixed pins (24) fixed in the pin holes. . A groove (20) defined in the rod engagingly accommodates the engaging block. The rotary pins are manually rotated outwardly from the cavity. The engaging block is released from the groove by the rod prosing against the engaging block and thereby elastically deforming the bridge. The rotary pins are rotated out to an unfolded position in which another groove (21) defined in the rod engagingly accommodates the engaging block.

Abstract: A foldable transformer comprises an insulative enclosure (2) and a plug (16) rotatably attached to the enclosure. The enclosure includes a storage cavity (4), a pair of pin holes (14), and a pair of parallel slots (12). An arcuate engaging block (8) is formed on a bridge (10) between the slots. The plug includes a transverse rod (18), a pair of rotary pins (22), and a pair of fixed pins (24) fixed in the pin holes. A groove (20) defined in the rod engagingly accommodates the engaging block. The rotary pins are manually rotated outwardly from the cavity. The engaging block is released from the groove by the rod prosing against the engaging block and thereby elastically deforming the bridge. The rotary pins are rotated out to an unfolded position in which another groove (21) defined in the rod engagingly accommodates the engaging block.

Abstract: A keyswitch device consists of a keycap, a supporting plate, a switch, a first hinge member and a second hinge member. The supporting plate is arranged under the keycap and forms a tag defining an aperture, and a tab opposite the tag. The first hinge member has a planar portion and a biased portion angled from the planar portion. The planer portion defines an engaging hole therein and extends into the aperture of the tag. The engaging hole of the planar portion is locked by the tab. The first hinge member further forms shaft rods pivotably engaging the second hinge member, and engaging rods slidably received in the keycap. When the keycap is downwardly depressed, the switch is actuated to conduct a switch action. The biased portion is resiliently deflectable to the planar portion. The second hinge member pivotally connects between the supporting plate and the keycap.

Abstract: A key switch arrangement comprises a key cap, a key switch subassembly pivotally mounted to a bottom surface of the key cap, a circuit membrane under the key switch subassembly and forming a switch electrode thereon, a rubber member disposed between the key switch subassembly and the circuit membrane and forming a rubber cone for triggering the switch electrode when the key cap is compressed by an external force, and a supporting plate defining an opening therein. Engaging means is insert molded into the opening of the supporting plate, and comprises a pair of first and second engaging arms for pivotally engaging with the key switch subassembly.

Abstract: A key switch comprises a key cap, a support device, a support board, a membrane circuit, and a base. A number of slots formed on sides of the support device engage with hooks of the key cap whereby the key cap is slidably engaged with the support device. A number of protrusions outwardly extends from edges of a bottom surface of the support device to engage corresponding U-shaped positioning portions. Thus, the height of the key switch is limited and the assembly thereof is simplified.