Abstract: This invention relates to a three-phase thermal protector having two pairs of fixed and movable contacts for opening and closing the neutral of wye-connected phase windings of a three-phase induction motor.

Abstract: A structure for mounting a motor protector substantially as a thermally responsive switch in an enclosed electric compressor including an electric motor and a compressing means provided in a closed housing. The structure includes a terminal support provided air-tightly through an upper wall of the compressor housing, a plurality of conductive pins for connecting an external power-supply circuit to the motor, the conductive pins projecting inside and outside the terminal support. One of the inner conductive pins is conductively connected to a terminal pin provided in the motor protector or to an equivalent thereof. Thus, the motor protector is disposed and held within the compressor housing so that heat is exchanged between the motor protector and a coolant gas. A motor winding is connected to the other terminals and the other conductive pins provided in the terminal support.

Abstract: A thermally responsive snap-acting switch consists of an elastic plate cantilever mounted at one end on a header, a thermally responsive element which includes a central dish-shaped portion for inducing snap action and one end of which is connected with the other end of the elastic plate in an opposed relation to the elastic plate, a support one end of which includes a portion receiving a connection between the elastic plate and the thermally responsive element so that it slides and is inclined on the receiving portion, and a projection which exerts a force on the dish-shaped portion of the thermally responsive element to calibrate the operative temperature of the thermally responsive element. The calibration is performed either by employing a screwed stud as the projection or by plastically deforming the receiving portion of the support.

Abstract: A snap action type thermally responsive switch comprising a fixed contact secured to a stationary frame, a rectangular thermally responsive plate having a central dish-shaped portion and being secured at one lengthwise end to the stationary frame and carrying a movable contact, the plate being determined at the ratio of length to width to be more than two, a calibrator screw projecting toward the convex side of the dish-shaped portion to depress thereagainst at the normal temperature, the calibrator means being positioned to contact the dish-shaped portion within the region ranging from the central point to a point away from the central point that is equal to one-third of the width of the plate in the direction toward the secured end thereof.

Abstract: In a hermetic type thermally responsive switch comprising a fixed contact support having a fixed contact at its end and cantilever disposed in a hermetically sealed vessel, a elongated support supporting a thermally responsive disk which has a movable contact and cantilever disposed in said vessel through a connecting means; said fixed contact support comprises laminated metallic sheets each having different elastic modulus, while a spacer means is interposed in electrically, thermally insulated relationship between said elongated support and said connecting means so as to calibrate the snap temperature of said disk.

Abstract: In a seat belt retractor having a reel to which a belt is anchored at one end and which is spring biased pawl is pivotally mounted on a retractor frame for movement into and out of engagement with a pair of ratchet-toothed flanges provided on the reel. Disposed coaxially with the reel are a cam wheel rotatable simultaneously therewith and an inertia wheel rotatable through a predetermined angle relative to the cam wheel. These wheels have on and along their peripheries protuberances which are disposed at a predetermined pitch. During rotation of the reel in a direction of belt extension at relatively low acceleration, the inertia wheel is rotated in synchronism with the cam wheel via a spring. This spring yields, upon a high acceleration being imparted to the reel in the direction of belt extension, to permit the inertia wheel to lag behind the cam wheel by the predetermined angle.