Abstract: A cryogenic freezer and a method of controlling temperature within the cryogenic freezer. The cryogenic freezer includes an inner vessel. The inner vessel defines a storage chamber. The cryogenic freezer includes an outer vessel surrounding the inner vessel. The outer vessel may define a vacuum-insulated space in between the outer vessel and the inner vessel. The cryogenic freezer includes a temperature sensor configured to measure a temperature within the storage chamber. The cryogenic freezer includes a controller coupled to the temperature sensor. The controller is configured to pulse an amount of cryogen into the storage container to control the temperature within the storage container.

Abstract: A cryocooler is described that can include a pressure wave generator, and a refrigeration device (for example, a cold-head), which can be used to liquefy a gas when the gas is exposed to a surface of the refrigeration device. The pressure wave generator can include one or more motors. Each motor can include a stator, and at least one electrical coil wound around a portion of the stator. The electrical coil can generate a reversing magnetic field when alternating electric current is passed through the electrical coil. The motor can further include a pressurized container that can be placed within the space enclosed by the stator, and a piston that can be placed inside the pressurized container. The stators can be placed external to the pressurized container. The piston is made by combining magnets that have opposite and transverse polarities, and are combined adjacently on a common reciprocating axis.

Abstract: A cryocooler is described that can include a pressure wave generator, and a refrigeration device (for example, a coldhead), which can be used to liquefy a gas when the gas is exposed to a surface of the refrigeration device. The pressure wave generator can include one or more motors. Each motor can include a stator, and at least one electrical coil wound around a portion of the stator. The electrical coil can generate a reversing magnetic field when alternating electric current is passed through the electrical coil. The motor can further include a pressurized container that can be placed within the space enclosed by the stator, and a piston that can be placed inside the pressurized container. The stators can be placed external to the pressurized container. The piston is made by combining magnets that have opposite and transverse polarities, and are combined adjacently on a common reciprocating axis.

Abstract: A convertible stadium includes a playing field, a seating area, a stationary roof structure and a large, heavy roof panel mounted for movement with respect to the stationary roof structure, A plurality of cable drums are mounted for movement together with the roof panel. Each cable drum has at least one cable wound thereabout. The cable is secured to the stationary roof structure and is payable from the respective cable drum. The system is designed so as to minimize movement between the cable and the roof panel, so there will be no possibility of frictional engagement therebetween.

Abstract: A movable roof member includes a transport mechanism that is constructed and arranged to permit the roof member to move in a predetermined path with respect to the underlying structure of the supporting edifice. The transport mechanism includes structure for supporting both ends of the roof member, which bridges an otherwise open area of the edifice. In order to permit some flexure and movement of the roof member with respect to the underlying edifice, as will inevitably occur as a result of natural forces such as winds, a lateral release system is provided for maintaining the transport mechanism in a predetermined orientation while simultaneously permitting a limited amount of movement of the roof member in a direction that is nonparallel to the predetermined path of movement. The lateral release system has been found to be most effective when it is provided at but one end of the roof member.

Abstract: A convertible stadium includes a playing field, a seating area, a stationary roof structure and a large, heavy roof panel mounted for movement with respect to the stationary roof structure, A plurality of cable drums are mounted for movement together with the roof panel. Each cable drum has at least one cable wound thereabout. The cable is secured to the stationary roof structure and is payable from the respective cable drum. The system is designed so as to minimize movement between the cable and the roof panel, so there will be no possibility of frictional engagement therebetween.

Abstract: A movable roof member includes a transport mechanism that is constructed and arranged to permit the roof member to move in a predetermined path with respect to the underlying structure of the supporting edifice. The transport mechanism includes structure for supporting both ends of the roof member, which bridges an otherwise open area of the edifice. In order to permit some flexure and movement of the roof member with respect to the underlying edifice, as will inevitably occur as a result of natural forces such as winds, a lateral release system is provided for maintaining the transport mechanism in a predetermined orientation while simultaneously permitting a limited amount of movement of the roof member in a direction that is nonparallel to the predetermined path of movement. The lateral release system has been found to be most effective when it is provided at but one end of the roof member.

Abstract: A post attachment device for connecting a helmet to a head and neck support. The device includes a post anchor having a base, a button, a resilient member, a post, a retainer and a catch having a slot with a larger first section connected by a channel to a smaller second section. The button is positioned in an indention in the base with the resilient member positioned therebetween. The post extends through the button, the base and the helmet. The retainer is secured on the post adjacent the inner surface of the helmet. To secure the post attachment device, the catch is orientated over the post. The button is then pressed into the base while the catch is moved backwards to move the post into the second section of the slot.

Abstract: A hitch assembly is disclosed for use with endless track land vehicles that allows an implement mounted by a three-point hitch arrangement up to about 15 degrees arcing movement off the longitudinal axis oriented in the direction of travel of the land vehicle. A pivotal mounting means is connected to two horizontal arms which are joined at the rear by another member. The mounting means and connecting arms form a four-sided polygonal structure which can be raised or lowered by a hydraulic ram since the arms are pivotally connected at the corners. Finally, a telescoping linkage assembly, after the hitch assembly has been raised through 75 percent of its travel, urges the implement mounting means on the rear vertical connecting arm into a common, pre-selected travel position.