Trw Limited

Other

The United States of America as Represented by the United States

The United States of America as Represented by the Administrator of the

Robert W Vaughan

Robert J Jones

Michael K O'Rell

Clyde H Sheppard

Howard E Green

Robert A Buyny

John F Creedon

James G Vaughan

A clutch for engaging and disengaging rotary systems and devices such as alternators and generators, which includes a hollow engaging knob fitted with projecting engaging pins, a spindle shaft and plate mounted on a rotating shaft and cooperating with the engaging knob and engaging pins, and a drive pulley rotatably positioned on the rotating shaft and having seats for selective registration with the engaging pins. A spring is positioned in the hollow cavity of the engaging knob to facilitate biasing of the engaging pins through apertures in the spindle plate and in registration with the seats in the drive pulley when the clutch is engaged. Retraction of the engaging knob and engaging pins against the bias of the spring facilitates retraction of the pins from the pulley seats, and effects disengagement of the clutch and free rotation of the drive pulley.

Clutch

Vinyl polybutadiene maleimide prepolymers which are peroxide curable are provided. The prepolymers are formed from the reaction product of a vinyl polybutadiene providing pendant vinyl groups and a maleimide and, more particularly, a mixture of aliphatic maleimides with cycloaliphatic or aromatic maleimides in combination with a peroxide-free radical initiator. The prepolymer is a vinyl polybutadiene backbone structure having grafted maleimide polymers forming cross-linking between polybutadiene backbone segments. The resultant prepolymer can be subsequently cured to a hard resin by heating in the presence of a peroxide-free radical initiator to form cross-linking between vinyl polybutadiene structures through the pendant vinyl groups. The resultant hard resin provides strength retention at elevated temperatures and exhibits a flexibility and strength without being brittle.

Flexibilized vinyl polybutadiene maleimide resins

Clock face

Vinyl polybutadiene bisimide copolymers which are peroxide curable are provided by two methods of formation. In the first method a bisimide cross-linked vinyl polybutadiene prepolymer is formed by combining a high vinyl content polybutadiene providing pendant vinyl groups with a bisimide in the presence of a first free radical initiating catalyst. The resultant cross-linked prepolymer is cured to a hard resin by the formation of additional cross-linkages through the pendant vinyl groups by heating the prepolymer to a temperature of at least about 300.degree. F. in the presence of a second free radical initiating catalyst. The second method discloses a method wherein the bisimide cross-linkages are formed in situ. In the second method, a high vinyl content polybutadiene providing pendant vinyl groups is reacted with maleic anhydride to form a maleic anhydride vinyl polybutadiene adduct. The adduct is subsequently combined with an aromatic polyamine and a free radical initiating catalyst. The mixture is heated to about 250.degree. F. to form a prepolymer having bisimide cross-linkages between the vinyl polybutadiene backbone segments. By continuing to heat the prepolymer to at least about 300.degree. F. still in the presence of the free radical initiating catalyst, the prepolymer is cured to a hard resin by the formation of cross-linkages between the pendant vinyl groups.

Vinyl polybutadiene bisimide copolymers

Structurally stronger titanium articles are produced by a weld-bonding technique comprising fastening at least two plates of titanium together using spot-welding and curing an adhesive interspersed between the spot-weld nuggets. This weld-bonding may be employed to form lap joints or to stiffen titanium metal plates.

Weld-bonded titanium structures

Structurally stronger titanium articles are produced by a weld-bonding technique comprising fastening at least two plates of titanium together using spot-welding and applying a bead of adhesive along the edge of the resistance spot-welded joint which, upon heating, flows and fills the separation between the joint components.

Capillary flow weld-bonding

A low temperature curing polymeric adhesive composition may be made by reacting an amino alcohol having between 1 and 3 amino groups and between 2 and 5 hydroxyl groups with a stoichiometric amount of a carboxylic acid or derivative. Free radical catalysts and accelerators may be added to speed the cure of the adhesive. These adhesive resins can be cured at or near ambient room temperature and are highly desired for fabrication of bonded materials possessing long fatigue life because of reduced stresses that might be induced at higher cure temperatures. A generalized formula may be illustrated as follows: ##EQU1## WHERE R' may be hydrogen, alkyl, or cycloalkyl; R' may be hydrogen or alkyl; R is an alkyl; R.sub.1 may be hydrogen, an alkyl, or phenyl; m is an integer from 1 to 3; and n is an integer from 1 to 2.

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Manhattan Beach, CA, United States of America

Robert W Vaughan