Abstract: A moulded seal for a fluid seal arrangement which requires no trimming of the sealing which comprises an elastomeric frusto-conical body part having a sealing lip at its inner face in spaced disposition relative to the lesser diameter end thereof. In use, the space between the sealing lip and the adjacent free end of the body is subjected to an hydrodynamic pumping action away from the lip on displacement of the shaft to reduce fluid pressure in the region of the lip and hence discourage leakage. Various seal arrangements embodying the moulded seal are also disclosed.

Abstract: A face seal arrangement for effecting a fluid seal between a housing and a shaft rotatable therein and comprising a sleeve-like diaphragm interposed between an annular shell and a sealing member has a compression spring of rectangular section material loading the diaphragm outwardly relative to the shell, the spring being disposed between radial flanges of the diaphragm. Each flange has a tapered rim at its axially outer face, the rims being engaged in seatings in the shell and sealing member respectively. The arrangement is a unitized structure in that the sealing ring is held captive relative to the shell with the spring loaded sealing member interposed therebetween and freely movable in the axial direction of the arrangement.

Abstract: A face-seal arrangement for effecting a fluid seal between a housing and a shaft rotatable therein and comprising a sleeve-like diaphragm interposed between an annular shell and a sealing member and having compression spring means loading the diaphragm outwardly relative to the shell further includes a forged sealing ring having a profiled periphery thereto, a sealing surface being provided on the sealing member for engagement with a smooth sealing surface on the sealing ring. The arrangement is a unitized structure in that the sealing ring is held captive relative to the annular shell with the spring-loaded sealing member interposed therebetween and freely movable in the axial direction of the arrangement.

Abstract: A shaft-seal assembly is disclosed which includes a thin polytretrafluorethylene sleeve-like member in line sealing contact with the sealing face of a flexible, frusto-conical support and through which the sealing pressure of a garter spring and the support is applied to the shaft to be sealed.

Abstract: A comparison circuit for use in an apparatus including a source of a coherent light beam of low divergence for quickly and simultaneously establishing a plurality of reference lines or planes for use in leveling, squaring, plumbing, and other alignment functions and for controlling the operation of construction equipment is disclosed.The present invention is a circuit that finds particular utility in automatically adjusting the orientation of the tool. More particularly the present invention is a circuit for comparing the amplitude of a first alternating current signal to the amplitude of a second alternating current signal, such signals being in phase with one another and having the same frequency.

Abstract: An end face seal has a sealing bush with an external circumferential shoulder and is surrounded by an elastomeric loading sleeve which has an inwardly-directed frusto-conical diaphragm abutting the shoulder to load the sealing bush and a radial web directed towards the sealing bush.