Abstract: Intrusion of chips is prevent into gaps formed between inner end surfaces of master jaws and a chuck cover. A top plate is disposed at the center of an end surface of a chuck body. Top covers, which move in conjunction with movements of master jaws when opening and closing the chuck, are disposed in top cover guide recesses formed at three positions on the top plate. Each top cover abuts the center-side end parts of serrated surfaces formed on both widthwise sides of a respective master jaw and the center-side end part of a step section of a stepped claw therebetween, and the top covers close gaps formed at the center-side end parts by the movements of the master jaws at all times by moving in conjunction with movement of the master jaws.

Abstract: A device for activating a screw cap of a container comprises a first holding device for holding the screw cap, and a drive for activating the first holding device, wherein the first holding device is movable in a plane. The first holding device comprises a coupling device for the coupling of an external drive, and therefore the first holding device is movable in the plane.

Abstract: A chuck apparatus grips a workpiece by a gripping section having a pair of chuck members. The chuck apparatus is equipped with a cover member and pressing members. The cover member includes insertion holes through which fingers of the chuck members are inserted, and seal members that surround the insertion holes and abut against the fingers. The cover member is attached to a body so as to cover base portions of the chuck members, and is elastically deformable so as to follow displacement of the chuck members. The pressing members press the seal members against the fingers.

Abstract: An upright chuck assembly includes a base having two elongate notches respectively defined in two sides thereof. A rotary device is connected to the base and includes a horizontal gear set and a vertical gear set which are engaged with the horizontal gear set in the body of the rotary device. An insertion extends from the horizontal gear set and is inserted into one of the adjustable members. The vertical gear set has a connection portion on the top thereof, and a T-wrench is mounted to the connection portion. The rotary device is cooperated with a vertical machine center.

Abstract: A pair of gripping sections performs opening and closing operations along a base member through displacement of a piston by means of a pressure fluid supplied to a chuck body. A pair of fingers, which constitute the gripping sections, is openable and closable in directions perpendicular to opening/closing directions of the gripping sections, by means of a driving force supplied from a driving section. The gripping sections are positioned with respect to a workpiece by actuating the pair of fingers to perform the opening/closing operation. Thereafter, by supplying the pressure fluid, the workpiece is gripped at a desired gripping position by means of the gripping sections.

Abstract: A chuck especially for a machine tool that operates in a universal manner as a two, three or four jaw chuck. The chuck (10) comprises four jaws (25) arranged in diametrically opposed pairs on the front face (12) of the chuck (10). The chuck (10) including drive pinions (36, 37) that drive a scroll (39, 239) that co-axially carries a differential gear train including a pair of differential gears (50, 51) one driving one pair of jaws (25) and the other driving the other pair whereby the differential gear train apportions the drive between the pair of jaws so that one pair may move independently of the other pair.

Abstract: A hammer-drill chuck comprises a generally tubular chuck body centered on a chuck axis and having a central axially extending bit-receiving passage and a radially outwardly open chuck-key centering hole. A plurality of jaws radially but not angularly displaceable in the chuck body have inner ends engageable with the drill-bit shank in the passage. An adjustment ring connected to the jaws moves same radially synchronously and thereby centers the bit in the body by engagement of the inner ends with the shank. This ring is formed with axially backwardly directed teeth positioned axially forward of the centering hole such that when a chuck key is fitted into the centering hole its crown gear meshes with the ring teeth. A locking sleeve angularly nondisplaceable on the body carries at least one tooth axially engageable between the ring teeth.

Abstract: In a scroll chuck accommodating a scroll plate, a dust guard is fitted in a continuous groove formed by the scroll thread of the scroll plate. The dust guard consists of an elastic cord made of a material having rubber-like elasticity, and has such a length as to extend over the full length of the continuous groove. The outside surface of the elastic cord is substantially flush with the crest of the scroll thread.

Abstract: A lathe chuck is disclosed which includes a plurality of gripping jaws actuated by jaw screws. The screws are rotatably mounted in openings extending radially from the central bore of the chuck. The screws include a central passageway having a spring-biased plunger therein which is adapted to be caused to project from the passageway, across the chuck bore, and into engagement with the passageway of a diametrically opposed jaw screws. With the two jaw screws thus interlocked, they may be rotated together by turning only one jaw screw, thereby moving the opposed, linked gripping jaws in unison an identical distance in one direction. The chuck also includes means for the microadjustment of each jaw position, means for interlocking the movements of selected jaws for simultaneous convergence, and means for immobilizing the gearing means and thereby those jaws then engaged; it provides for repetitive return of the coordinated jaws to a prior position, and automatic centering of round stock.

Abstract: A chuck for a machine tool is disclosed which comprises a cylindrical scroll board with a scroll groove being formed on one end surface thereof and having three radial slots formed therethrough at equi-angular intervals, three slider blocks radially movably received within the radial slots and each provided on the under surface with a number of arcuate grooves so as to be in communication with the scroll groove and on the radially inner end with an engaging element, a cup-shaped cover board adapted to rotatively receive therein the scroll board and provided on the annular cover plate constituting the bottom thereof with three radial slots at equi-angular intervals, three claws radially movably received within the radial slots of the cover plate and each provided on the under surface with a number of arcuate projections so as to be in mesh with the scroll groove, and a manipulating member axially movably received within a bore formed in the scroll board centrally thereof and adapted to be moved by an actuating