Abstract: A deformable membrane assembly comprises a deformable membrane (70) in contact with a body of fluid (90) and a selectively operable adjuster for adjusting the pressure of the fluid (90) for causing distension of the membrane (70) in accordance with a predefined form. The membrane is held peripherally by a bendable supporting member (50) that is coupled to a fixed support by at least three engaging members (82) at spaced locations round the supporting member (50). An engaging member (82) is provided at or proximate at least one point round the supporting member (50) where the profile of the supporting member (50) corresponding to the predefined form of the membrane (70) exhibits locally maximum or minimum curvature in the direction of distension of the membrane (70).

Abstract: A deformable membrane assembly comprising a fixed support, a fluid-filled envelope, one wall of which is formed by an elastic membrane that is held under tension around its edge by a flexible membrane supporting member, the supporting member being coupled to the fixed support at a plurality of discrete control points around the supporting member by engaging members for controlling the position of the membrane edge; and an adjuster for adjusting the pressure of the fluid within the envelope to adjust the shape of the membrane; wherein at least three control points are provided that are situated around the membrane edge at spaced locations selected to increase the energy of the lowest order out-of-plane bending mode of the supporting member while allowing the membrane to deform according to one or more selected Zernike polynomials. An article of eyewear comprising such a deformable membrane assembly is also disclosed.

Abstract: A deformable membrane assembly comprises a deformable membrane (70) in contact with a body of fluid (90) and a selectively operable adjuster for adjusting the pressure of the fluid (90) for causing distension of the membrane (70) in accordance with a predefined form. The membrane is held peripherally by a bendable supporting member (50) that is coupled to a fixed support by at least three engaging members (82) at spaced locations round the supporting member (50).

Abstract: An adjustable fluid-filled lens having a rear surface, a front surface, and a body of fluid between the front and rear surfaces. The lens incorporates a diffractive pattern within the fluid.

Abstract: A variable-power lens includes first and second lens elements one behind the other along an optical axis of the lens. Each element has opposed planar and curved surfaces such that the thickness of each element in a direction parallel to the optical axis varies in a direction transverse to the optical axis. The elements are relatively moveable in the transverse direction, whereby the power of the lens may be varied. The elements are arranged such that the curved surface of the first element is adjacent the second element and the planar surface of the first element bears a diffractive pattern.

Abstract: A deformable membrane assembly comprises an at least partially flexible fluid-filled envelope, one wall of which is formed by an elastic membrane that is held around its edge by a resiliently bendable supporting ring, a fixed support for the envelope and selectively operable means for causing relative movement between the supporting ring and the support for adjusting the pressure of the fluid in the envelope, thereby to cause the membrane to deform. The bending stiffness of the ring varies round the ring such that upon deformation of the membrane the ring bends variably to control the shape of the membrane to a predefined form. The moving means comprise a plurality of ring-engaging members that are arranged to apply a force to the ring at spaced control points.

Abstract: A deformable membrane assembly 1 comprising a fixed support; a fluid-filled envelope, one wall of which is formed by an elastic membrane 8 that is held under tension around its edge by a flexible membrane supporting member 2, 10, the membrane supporting member being coupled to the fixed support at a plurality of discrete control points 120 round the supporting member by respective engaging members for controlling the position of the membrane edge relative to the fixed support at the control points, and the member being unconstrained between said control points; and a selectively operable pressure adjuster for adjusting the pressure of the fluid within the envelope, thereby to adjust the shape of the membrane; wherein at least three control points are provided which are situated round the membrane edge at spaced locations on the member that are selected to increase the energy of the lowest order out-of-plane bending modes of the supporting member in response to loading through tension in the membrane that do n

Abstract: The present invention provides a deformable membrane assembly 1 comprising an elastic membrane 8 that is held under tension around its edge by a bendable membrane supporting member 2,10, a body of fluid in contact with one face of the membrane, the pressure of the fluid being controllable for adjusting the shape of the membrane, and one or more bending controllers 24 acting on the supporting member 2, 10 to control the bending of the supporting member in response to loading through tension in the membrane. The bending stiffness of the membrane-supporting member 2, 10 varies round its extent to control the profile of the edge of the membrane 8; etc. upon actuation. A variety of different types of bending controllers are disclosed which permit out-of-plane bending of the supporting member 2, 10 but prevent or control in-plane bending or deformation of the supporting member.

Abstract: A prewetted cleaning wipe for cleaning surfaces and having low volatile organic chemical and low nonvolatile residue properties comprising a wipe substrate wetted with an aqueous solution of high purity water and an effective amount of an acetylenic alcohol surface active agent. The surface active agent is preferably an acetylenic diol. Preferred acetylenic diols include dimethyl octynediol and tetramethyl decynediol.

Abstract: A prewetted cleaning wipe for cleaning surfaces and having low volatile organic chemical and low nonvolatile residue properties comprising a wipe substrate wetted with an aqueous solution of high purity water and an effective amount of an acetylenic alcohol surface active agent. The surface active agent is preferably an acetylenic diol. Preferred acetylenic diols include dimethyl octynediol and tetramethyl decynediol.

Abstract: The present invention relates to a siloxane-oxyalkylene copolymer surfactant having the formula MD.sub.x D'.sub.y M wherein M represents (CH.sub.3).sub.3 SiO.sub.1/2 or R(CH.sub.3).sub.2 SiO.sub.1/2, D represents (CH.sub.3).sub.2 SiO.sub.2/2, D' represents (CH.sub.3)RSiO.sub.2/2, and the value of x+y is from 48 and 220, and the ratio x/y is from 5 to 15 inclusive. In the above formulae for M and D', R is a polyether-containing substituent selected from the group consisting of (1)--C.sub.n H.sub.2n O(C.sub.2 H.sub.4 O).sub.a (C.sub.3 H.sub.6 O).sub.b R' moieties having weight average molecular weights of from about 2300-3200 and wherein n is 3-4, the ratio a/b is from 0.5 to 1.3 inclusive, R' represents hydrogen, an alkyl group of 1-4 carbon atoms or --C(O)CH.sub.3 and (2)--C.sub.n' H.sub.2n' O(C.sub.2 H.sub.4 O).sub.a' (C.sub.3 H.sub.6 O).sub.

Abstract: The present invention relates to a siloxane-oxyalkylene copolymer surfactant having the formula MD.sub.x D'.sub.y M wherein M represents (CH.sub.3).sub.3 SiO.sub.1/2, or R(CH.sub.3).sub.2 SiO.sub.1/2, D represents (CH.sub.3).sub.2 SiO.sub.2/2, D' represents (CH.sub.3)RSiO.sub.2/2, and the value of x+y is from 48 and 220, and the ratio x/y is from 5 to 15 inclusive. In the above formulae for M and D', R is a polyether-containing substituent selected from the group consisting of(1) --C.sub.n H.sub.2n O(C.sub.2 H.sub.4 O).sub.a (C.sub.3 H.sub.6 O).sub.b R' moieties having weight average molecular weights in the range 2300-3400 and wherein n is 3-4, the ratio a/b is from 0.5 to 1.3 inclusive, R' represents hydrogen, an alkyl group of 1-4 carbon atoms or --C(O)CH.sub.3 and(2) --C.sub.n' H.sub.2n' O(C.sub.2 H.sub.4 O).sub.a' (C.sub.3 H.sub.6 O).sub.

Abstract: This invention relates to a method for preparing a flexible polyurethane slabstock foam by reacting a polyol, an organic diisocyanate, and water in the presence of at least one urethane catalyst, a siloxane-oxyalkylene copolymer surfactant and, optionally another blowing agent, where the surfactant has the average formula MD.sub.x D'.sub.y M where M is (CH.sub.3).sub.3 SiO.sub.1/2 or R(CH.sub.3).sub.2 SiO.sub.1/2, D is (CH.sub.3).sub.2 SiO.sub.2/2, D' is (CH.sub.3)RSiO.sub.2/2, and the value of x+y is 48 to 220, the ratio x/y is 5 to 15 inclusive, R is a polyether-containing substituent selected from the group consisting of (1) --C.sub.n H.sub.2n O(C.sub.2 H.sub.4 O).sub.a (C.sub.3 H.sub.6 O).sub.b R' group having weight average molecular weights in the range 2300-3400 and wherein n is 3-4, the ratio a/b is from 0.5 to 1.3 inclusive, R' represents hydrogen, an alkyl group of 1-4 carbon atoms or --C(O)CH.sub.3 and (2) --C.sub.n' H.sub.2n' O(C.sub.2 H.sub.4 O).sub.a' (C.sub.3 H.sub.6 O).sub.