Abstract: A compressor for compressing a refrigerant is described. The compressor comprises a case having at least one curved portion and at least one opening, wherein the opening is located in the at least one curved portion, an electrical terminal arranged within the at least one opening and fixed to the case, wherein the at least one opening is an elliptical opening. Also, an electrical terminal for use with a compressor is described.

Abstract: A wood screw has a resilient shaft carrying a spiral thread of nominal pitch from the tip. The thread is interrupted at a plurality of intervals and the shaft is torsionally resilient. When the screw fastener is driven, the shaft twists and contracts so that the thread in the mating material has a pitch which is less than the nominal pitch. The interrupted thread may consist of a plurality of resilient lobes.

Abstract: A tamper proof package for determining whether or not a package has been opened or tampered with before opening the package is provided. The package has an electrical conductor of known resistance which is so positioned that any attempt to open the package or to tamper with the contents destroys all or part of the conductor. The resistance of the conductor can be measured at the time of sale or during the shelf life of the package to determine whether or not the package has been opened or tampered with.

Abstract: The screw has a conventional threaded body, and a tapered leading end for easy entry to a tapped hole. A projection extends radially from the tapered end portion and when the longitudinal center lines of the screw and hole are misaligned, makes first contact with the threads on the tapped hole. As the screw is turned, the projection follows the tapped threads of the hole to bring the machine screw into alignment. When the projection tracks the internal hole threads, the positional relationship between the projection and the first screw thread brings the starting point of the first screw thread into contact with the starting point of the first thread at the entrance of the tapped hole.

Abstract: A fastener, such as a screw or bolt, has a recessed head for receiving a driver therein. Four arcs intersect, providing a squarish opening to the recess, which has circularly concave walls descending from the arcs to the base of the recess. The driver comprises a shaft having a somewhat spherical head in profile. Four arcs intersect to form the external surfaces and a squarish cross-section for the head. The recessed arcs are not concentric with the head arcs when the fastener and driver are mated, and the arc radii of the recess exceed the corresponding arc radii of the mated head. Transmission of force between driver and fastener is efficient even when the driver is tilted relative to the fastener axis.

Abstract: A thread-rolling method as well as thread-rolling dies and method for manufacturing the dies. The shank on which the thread is rolled has a tapered free end region, and the dies which are used for rolling the thread are initially made up of a pair of individual sections having flat and inclined die faces with these sections subsequently joined to each other to form the complete die. The threads may be of lobular configuration, and during the rolling of the thread itself the lobes are simultaneously formed. The lobes for the threads are achieved directly from the thread-rolling dies by pressing across the ridges thereof tools which form in the ridges indentations having a predetermined pattern of distribution which will achieve the required distribution of the lobes on the thread which is rolled.

Abstract: A vibration-resistant, thread-forming screw. The screw has an elongated shank made of a solid, one-piece body and provided with an interior core portion which, in any plane normal to the shank axis, has a circular configuration. Integral with and projecting radially from this core portion are a plurality of lobes uniformly distributed circumferentially about the shank axis and extending along spirals which progress angularly about the shank axis in a direction opposite to the thread. Each lobe has, in the direction in which the screw is turned into a body, an elongated leading leg which progresses gradually away from the shank axis in the latter direction of turning and a relatively short trailing leg which returns abruptly toward the shank axis before joining the leading leg of the next lobe. A specially shaped die for forming the screw.