Bellows

About: Bellows is a research topic. Over the lifetime, 15312 publications have been published within this topic receiving 73914 citations.

Method and apparatus for manufacturing packaging bags, and bags obtained thereby

Abstract: The present invention relates to a method of manufacturing packaging bags having lateral bellows, the method being characterized by the fact that it comprises the steps consisting in: forming respective cutouts ( 150, 160 ) in each of the two lateral, bellows-forming zones of a packaging bag sheet ( 100 ) so that the bag has only two thicknesses superposed at the mouth of said bellows, at least over a portion of its width; and heat-sealing ( 184, 186 ) the adjacent edges of the sheet to the peripheries of the cutouts ( 150, 160 ) to close the bag. The invention also provides apparatus for implementing the method and bags obtained thereby.

Load break switch

Abstract: A single-phase ground enclosed load break switch for distribution voltages has a hermetically sealed cylindrical metal housing of from 2 to 6 inches diameter which contains an insulating gas under pressure. The switch has a movable contact assembly to contact a pair of opposed stationary coaxial conductors within the housing. Movement of the contact assembly along one conductor breaks the connection with the other conductor and simultaneously reduces the sliding contact force on the first conductor. The switch has conductive bands coaxially positioned near the housing around the conductors for low voltage measurements monitoring conductor energization and contact position. A rocking bellows at the fulcrum of a crank actuator provides a compact hermetic seal for the actuator without excessive strain of the bellows. A safety interlock with a visual indicator locks the contact assembly in case of a loss of pressure. Excessive pressure in the switch causes the bellows to be punctured with consequent locking of the contact assembly. The switch is small enough to be mounted directly on a transformer or placed into a cable, without the need for a separate enclosure.

Flexible dip tube for liquid dispenser

Abstract: A flexible dip tube for a liquid dispenser, the tube comprising an elongated integrally formed element having elongated end sections and an elongated intermediate section with a pair of spaced bellows defining flexible/weight portions respectively between one end section and the intermediate section and between the other end section and the intermediate section, one of the bellows functioning as a weight filled with liquid causing the tube to flex at the other end of the bellows.

Pressure controlled switching valve for refrigeration system

Abstract: A refrigerant flow switching device for alternatively conveying flow of refrigerant from either a high presure or a low pressure evaporator to a compressor of a refrigeration system and a refrigerator using such a refrigeration system. The device utilizes the pressure difference between the higher pressure refrigerant from the high pressure evaporator and the lower pressure refrigerant from the low pressure evaporator or atmospheric pressure to open and close a first flow controller of the device positioned in a conduit leading from the high pressure evaporator to the compressor. The device further comprises a second flow controller, such as a check valve positioned in a conduit leading the low pressure evaporator to the compressor, which stays open only when the first flow controller is closed. The first flow controller comprises a bellows which is expanded from a first position to a second position by the pressure of refrigerant from the high pressure evaporator against a constant force provided by a compression spring, positioned against the bellows. The bellows attached through "U" shaped preloaded springs to a gate having an orifice causes the gate orifice to snap open or close when the bellows expands or compresses respectively for either allowing or preventing flow of refrigerant from the high pressure evaporator to the compressor.