Abstract: To assist in complying with strict Federal standards of cleanliness for industrial clean rooms, a sealed upholstered seat is placed in communication with an underlying relatively shallow breather bag which is retained by a seat pan attached to a rigid panel of the seat. The breather bag receives air from the upholstered seat when the seat is compressed and returns the same air to the seat as the seat expands. The escape of particulate matter from the seat into the atmosphere during usage of the seat is eliminated. A seat standard is received through an opening in the pan and passes between two spaced portions of the breather bag. The top of the standard is welded between the side walls of a channel member having side flanges which are attached to the bottom of the seat panel.

Abstract: To assist in maintaining the high degree of cleanliness required by Federal standards in industrial clean rooms, an upholstered seat is provided having an attached bellows which receives air from the seat when the seat is compressed and from which air is returned to the seat as the seat expands. There is no escape of air from the seat and bellows to the atmosphere and no induction of air from the atmosphere to the seat or bellows.

Abstract: To assist in maintaining the high degree of cleanliness required by Federal standards in industrial clean rooms, an upholstered seat is provided having a sealed filter unit through which air must flow when entering or exiting the seat structure. The filter unit is held in a sealed grommet installed in a hard base member on which is mounted a cushion. The base member and cushion are enclosed in an air-impermeable cover. The upholstered seat exceeds Federal standards in its ability to avoid contaminating clean rooms.

Abstract: To assist in maintaining the high degree of cleanliness required by Federal standards in industrial clean rooms, an upholstered seat is provided having a sealed filter element through which air must flow when entering or exiting the seat structure. A hard base member having a cushion mounted thereon is enclosed within an air-impermeable cover. The filter element in the form of a hydrophilic or hydrophobic sheet is placed between the hard base member and cover. The hard base member and cover contain air breathing apertures on opposite sides of the filter element. The upholstered seat exceeds Federal standards in its ability to avoid contaminating clean rooms.

Abstract: An automobile crankcase oil level indicator in ready reach of the vehicle driver has its main components molded from plastics and constructed for ease of assembly and installation. A minimum number of parts are employed to minimize manufacturing costs and to make the device compatible with mass production techniques. A unitized piston, piston rod and piston seal is employed in the device along with a unique simplified coupling between the main cup or housing and the face plate.

Abstract: A low cost, highly convenient, and non-complicated push button adjuster for chair backrests eliminates bulky and unsightly protruding levers, hand wheels and other external operators. A simple push button normally flush with the rear face of a backrest is depressed to shift a connected locking pin out of a detent slot in a backrest support bar so that the backrest is released for height adjustment. The push button and locking pin are spring-biased to the active locking position.