An exposure station is provided for making both negative-positive and positive-positive electrophotographic prints without employing reverse development techniques to develop one of the images. This is accomplished by projecting an image of a negative original onto a photoconductive-liquid crystal sandwich structure across which a potential is applied to form a temporary image in the liquid crystal, which temporary image is the reverse of the negative original. This temporary image is then proje...

A thread-supply arrangement for use in textile-manufacturing machines includes an accumulating drum which is mounted on a shaft and is to be selectively driven, together with other accumulating drums, when the shaft thereof is driven in rotation by an advancing belt or the like. A single pulley is mounted on the shaft for joint rotation therewith and for selected displacement longitudinally of the shaft between a plurality of positions in different ones of which different advancing belts are tra...

A positive dobby in which a pair of cam plates for moving each heald frame positively vertically are provided separately on the first cam shaft and on the second cam shaft parallel to the first cam shaft, whereby the dobby is constituted without enlarging the pitch between the cam plates corresponding to each heald frame.

Apparatus for interlocking the ends of first and second channel-shaped wall sections, comprising a substantially perpendicular first tongue integral with and extending inwardly from the end of the first wall section, with a slot at the juncture therebetween. A substantially perpendicular second tongue is integral with and extends inwardly from the second wall section. The second tongue is dimensioned for insertion through the aforesaid slot, and it has a detent arranged to cooperate in mechanica...

A positive dobby of the Hattersley type comprising a baulk having draw hooks hinged on the ends thereof which are engageable patternlike with back-and-forth movable draw knives, and a pivotable stop beam which tightly presses on the draw hook when in the patternlike lifted normal position and urges same against the stationary bar so that the locking surface of stop beam and draw hook lie, in the engaged condition, between the pivot axis of the draw hook on the baulk and the pivot axis of the sto...

A positive drive (10) utilizing clutch sleeves (46, 62) having internal splines (48, 64) for splined connection to clutch cams (30, 32) and certain of the clutch (42, 44) friction discs (54, 66) is provided. The positive drive utilizes a drive cam (22) comprising a radially inner ring portion (24) carrying cam surfaces (84, 86) for operative engagement with cam follower ramp surfaces (88, 90) of the clutch cams and radially outwardly extending arm portions (26) for mounting to the positive drive...

A method of selecting genetically transformed cells from a population of cells comprising introducing a desired nucleotide sequence and a co-introduced nucleotide sequence into the genome of a cell whereby the desired nucleotide sequence or the co-introduced nucletoide sequence induces a positive effect by giving the transformed cells a competitive advantage when the population of cells are supplied with an inactive compound thereby allowing the transformed cells to be identified and selected fr...

A catch adapted for mounting on the inside of a door includes a bolt mounted within a bracket to move between projected and retracted positions so the head of the bolt catches on and releases from a strike secured to the door frame. Connected to the head of the bolt is a resiliently flexible loop which normally urges the head into its projected position. When the loop is collapsed by manual operation of an actuator member, the head is retracted to release from the strike.

A draw hook having a bearing end, the outside circumference of which projects beyond the end of the baulk and serves simultaneously as stop against the recoil or repulsion knife and the stop rail. The drawing force for the movement of the heddle frame occurs from the draw hook directly through the bolt onto the baulk. The reaction and the holding force act directly onto the bearing end of the draw hook.

In a central air conditioning system wherein air flow is regulated by bellows inflation which is controlled by a bleed-type thermostat, simultaneous heating and cooling in a zone is prevented by disabling the bleed-type thermostat when the heating system is activated.