Abstract: A pushbutton switch has a housing with a reciprocating plunger. The plunger is made in two parts with a hollow insert pressed in place to provide a slot inside the plunger with a longitudinally extending portion and a spirally extending portion. A rotatable shaft fits within the hollow insert and has a plurality of teeth at the lower end of the shaft. An electrical contact member with three circumferentially extending fingers is on the shaft over the teeth and with the fingers extending downwardly for contacting three electrical terminals in the housing to which contact may be made by external leads. When the plunger of the switch is depressed, the shaft moves downwardly and rotates without rotating the electrical contact member. When the plunger is released, the shaft also moves upwardly and rotates in the reverse direction whereupon a tooth engages a pawl extending downwardly from the contact member, advancing the contact member in rotation and changing the state of the switch.

Abstract: A pushbutton has a body including a barrel and a plunger longitudinally movable in the barrel. A plurality of longitudinally extending teeth on the plunger engage a plurality of longitudinally extending teeth on a rotatable ratchet coaxial with the plunger. The ratchet is spring loaded against the plunger. A rotatable electrical contact cup connected to the ratchet makes or breaks contact with a fixed electrical terminal in the body. The plunger teeth each include a driving face which causes rotation of the ratchet. The driving face has an angle from a normal to the longitudinal direction of the plunger wherein the angle is at least the arctangent of the coefficient of friction between the ratchet teeth and the plunger tooth plus the arctangent of the effective coefficient of friction between electrical contacts in the switch, plus a margin of safety greater than the arctangent of the effective coefficient of friction between other parts of the switch. The angle is up to about 30 degrees.

Abstract: A pushbutton, momentary ON switch has a body including a barrel with longitudinally extending internal splines and ways between the splines. A plunger has radially extending lugs in the ways and is longitudinally movable in the barrel. A plurality of longitudinally extending camming teeth on the plunger engage a plurality of longitudinally extending camming teeth on a rotatable ratchet coaxial with the plunger. The ratchet is spring loaded against the plunger. The ratchet has radially extending dogs which fit into the ways when the plunger is retracted and come out of the ends of the ways when the plunger is advanced. A rotatable electrical contact cup connected to the ratchet and electrically connected to an external lead makes or breaks contact with a fixed electrical terminal in the body. The plunger teeth include a leading ramp face and a trailing ramp face wherein the leading ramp face extends a greater distance in the circumferential direction than the trailing ramp face.

Abstract: Apparatus for the drying of sludges and other fouling feed materials. A rotary screw type indirect heat exchanger is provided having at least one screw member. The screw member includes a helical-shaped flight having a helix angle of about 10 degrees or less and a surface roughness of about 63 micro-inches or less. Means are provided for rotating and heating the screw member and for spreading feed material onto the screw member. The apparatus operates at heat transfer rates and for a time period sufficient to reduce the moisture content of the feed material without requiring mechanical cleaning of feed material foulants from the screw member.

Abstract: An improved operator assembly for a rocker switch having a switch contact member movable relative to fixed contacts. Movement of an inner rocker moves the switch contact to turn the switch on and off. An outer rocker is located adjacent the inner rocker. The rockers are normally coupled by an inserted safety key for common movement. The rockers include stop components interengagable when the outer rocker is moved manually without a key toward a position corresponding to the off position of the switch, for example. The stop components are not interengagable when the outer rocker is moved toward a position which would turn the switch on. With this arrangement, when the key is removed with the switch on, the outer rocker can be manually operated to turn off the switch. However, if the switch is off, manual operation of the outer rocker in the opposite direction will not be accompanied by movement of the inner rocker and consequently the switch cannot be turned on.

Abstract: A pushbutton switch which permits partial actuation without a change of state, including a body, a cover and a contact cup having a plurality of tabs, the cup rotatably mounted on the cover. A plunger and ratchet mechanism mounted in the body incrementally rotate the contact cup and tabs upon successive actuations of the switch. A first terminal mounted on the cover is interruptibly in contact with one of the tabs as they are rotated by operation of the ratchet mechanism, while a second terminal mounted on the cover maintains electrical contact with the contact cup. A plurality of camming ramps formed in the cover are in intermittent communication with the tabs, first lifting them above a planar portion of the first terminal, then permitting one of them to come to rest on the planar portion of the terminal completing an electrical circuit between the first and second terminals. In another embodiment, a third terminal is mounted on the cover in a coplanar spaced apart relationship with the first terminal.

Abstract: A miniature ratchet type push button activated electrical switch having a mainspring and an auxiliary spring wherein spring rates, spring lengths and spring orientations are selected such that a substantial depression of the push button is required before electrical continuity is broken in a closed circuit. This configuration additionally serves to reduce the amount of audible noise generated by the switch during the ratcheting operation.

Abstract: A dual lighted rocker switch having a printed circuit board. Bi-pin terminated bulbs and conductive terminals are connected to a printed circuit board to form a sub-assembly. The sub-assembly is placed upon a cover, which is then slid in to place in a housing. The housing has a rib that acts as a stop to inhibit movement of a rocker which would cause the switch to short directly across the terminals of an external battery. The printed circuit board and cover improve the durability of the rocker switch. The printed circuit board is provided to make the assembly of the rocker switch easier. Thus the design of the switch provides for a reduction of cost and time in production of the rocker switch.

Abstract: An electrical switch adapted to be mounted on a gas strut assembly employed with a liftgate, for example, on an automotive vehicle. The switch is open or non-conducting when the strut is compressed and the liftgate is in the closed position. The switch is closed or conducting when the strut is extended enough to allow the liftgate to be unlatched and opened a predetermined distance as measured at the bottom of the liftgate. In one embodiment, the switch is affixed to the strut by an already existing fastener at the end of the strut that tightens the switch against a shoulder on the strut. In another embodiment, the switch fits snugly on the strut and is correctly positioned by the strut during initial assembly and actuation. Internally, the switch is provided with a pair of sleeve-like members that move longitudinally with respect to each other. One of the members has a pair of elongated contact fingers, while the other member is encircled by a metallic band.

Abstract: A miniature push-button switching apparatus having a housing for enclosing a plunger and a rotating ratchet mechanism for engaging and disengaging the switching contacts, the switching apparatus having a "momentary-on" position for temporarily engaging an electrical load in addition to a "stable-on" switch position with the ratchet mechanism employing a helical contact spring as a switching contact, the contact spring increasing the active length of the switching contact for significantly reducing possible spring yielding problems and further exhibiting improved resiliency properties which enhance the ratchet switching mechanism and reduce the possibility of spring distortion.