Abstract: A hitting device particularly adapted for use in the practice of martial arts, such as karate, which may be mounted on a vertical wall or post and carries a desired hitting surface. The bellows portion contracts when contacted axially to absorb the impact of the hitting force. Closable vents are provided in association with the bellows portion to allow for variation of the compressibility of the bellows, thereby varying the resistance to the hitting force by the hitting device. A force indicating assembly is also mounted on the hitting device for approximately indicating to a student the hitting force applied.

Abstract: A piston-cylinder unit for use in a disc brake assembly includes a cylinder and a hydraulically actuated piston received in the cylinder for axial movement therein. The unit has a flexible seal member with its opposite ends attached in sealing engagement to respective axially opposed portions of the piston and cylinder for elastic expansion and contraction in the axial direction. The flexible seal member and the opposing portions of the piston and cylinder form a chamber for receiving fluid pressure for actuation of the piston.

Abstract: The invention relates to a thermostatic control unit for radiator valves, this unit being of the type which has an adjustable bellows. The bellows is adjusted only during initial calibration of the thermostatic control unit or when the temperature setting of the unit is changed. The control unit includes a screw and nut arrangement in which the nut is attached to the free or moving end of the adjustment bellows. About three turns between the screw and the nut have been found suitable to provide a sufficient movement of the nut to allow an adequate adjustment of the bellows. A problem with prior units of this type is that if the screw is turned inwardly more than three turns the thread may bottom and thereby cause an excessive and damaging torque to be transmitted to the bellows. Alternately, if the screw is turned outwardly to disengage from the nut, the nut becomes cocked in the enclosed casing and it becomes impossible for the screw to re-enter the nut.

Abstract: A vacuum contactor for motor control applications and method of making the same that produces a switch of minimum size and extremely long mechanical life. This method comprises the step of heating the vacuum assembly to not over 450.degree. C during the evacuation process thereby allowing use of welded diaphragm bellows having the attendant advantages of much smaller size and longer life for a given length of stroke as compared to formed bellows. Because the operating conditions for motor control applications do not require as high voltage and current breakdown levels and thus the residual gas level inside the vacuum contactor enclosure need not be as low as in the case of circuit breaker (interrupter) applications, limiting the heating to not over 450.degree. C allows use of AM-350 stainless steel welded diaphragm bellows without sacrificing its required mechanical life.

Abstract: An engine, or prime mover, utilizing the various expansion properties of a gas or fluid, hereinafter termed the "working fluid", for converting the pressures associated with said expansion properties into useful work. The engine having a "piston" and "cylinder" arrangement, with suitable valves, camshafts, etc., whereby expansion of the working fluid moves the "piston" exhibiting kinetic energy in accordance with the magnitude of the kinetic effects on the piston.

Abstract: The present invention deals with a bag diaphragm comprising one or more flattened extremely flexible bags assembled together, to be mounted between rigid plates at a variable mean distance and to be inflated in operation by a variable pressure difference, and with an air damper operated by means of a bag diaphragm as mentioned above, this air damper being suitable for air conditioning plants, in constant flow, or constant variable flow, or mixing appliances, in fresh air and return air ducts, where an air flow is to be controlled, the operation of the air damper being possible without any electrical or pneumatic energy supply system, due to the particular characteristics of the aforesaid bag diaphragm and particular design of the damper.