Abstract: A mold structure having at least first, second and third mold parts stacked one on top of the other, each having structure thereon defining at least one part of a mold cavity. The second part is oriented between the first and third parts and has mold cavities on both sides thereof. A support structure is provided for supporting the first mold part for movement toward and away from the third mold part. Structure is included within the mold structure to limit the spacing between the first and second mold parts to a prescribed spacing so that as the first mold part is moved away from the third mold part, the second mold part will be spaced a prescribed distance away from both the first and third mold parts.The invention also includes a mold opening structure which is coaxially aligned with the elongate tie rod extending between the mold parts. This structure further effects a safe and positive opening of the mold structure.

Abstract: A caster with a braking apparatus includes a bracket and a wheel rotatably supported on the bracket, the wheel having a radially inwardly facing annular braking surface thereon between its axle and tread. A braking member has a braking surface thereon adjacent the braking surface on the wheel, and is supported for radial movement between braking and retracted positions in which the braking surface thereon is engaging and free of engagement with the braking surface on the wheel. Radial movement of the braking member is effected by a manually actuable lever. In a preferred embodiment, the bracket is pivotally supported on a bracket support and a further braking surface is provided on the bracket support. A braking element has a braking surface facing the braking surface on the bracket support and is moved by manual actuation of the lever between actuated and deactuated positions in which the braking surface thereon is respectively engaging and free of engagement with the braking surface on the bracket support.

Abstract: An apparatus for lifting a mold top upwardly away from a mold bottom includes a support for the mold bottom, a drive for moving the support horizontally, a frame, and a drive for moving the frame vertically. The frame has two gripping arrangements, movement of the support when the frame is in a lowered position causing the mold top to move to a position between the gripping arrangements, the gripping arrangements engaging vertical side surfaces on the mold top. Subsequent upward movement of the frame lifts the mold top due to engagement of the gripping arrangements with lips provided above the side surfaces. The gripping arrangements each include a roller support member pivotally supported on the frame and two rollers supported on each roller support member for rotation about vertical axes, the rollers rolling on the mold top side surfaces.

Abstract: A wheel bracket assembly includes an upper bracket having two spaced downwardly extending side flanges and a wheel carrying bracket pivotally supported between the upper bracket side flanges for pivotal movement about an axis. The second bracket has a generally horizontal top plate with a transverse, upwardly facing, concave groove and has side flanges which extend downwardly from opposite sides of the top plate and are adapted to pivotally support a wheel therebetween. Pivotal movement of the wheel carrying bracket in one direction is resisted by a resilient element which has one end engaging the top plate at a location within the groove, which extends away from such location approximately along the path of movement of the location about the pivot axis, which tapers in thickness toward such end, which has a semicylindrical head at the opposite end, and which has a transverse groove on each side thereof adjacent the head.

Abstract: A method and apparatus for injection molding articles from a thermoplastic or similar material. A plurality of molds are mounted on a turntable and are indexed to selected positions as the turntable rotates about its axis of rotation. Radial slots divide the turntable into sectors, each having a mold thereon. A clamping mechanism is provided which successively deflects each sector slightly from the plane of the turntable in order to precisely align the mold thereon with an injection nozzle and then securely clamps the halves of the mold together while the injection nozzle injects moldable material into the cavity in the mold. Interchangeable cavities with different size and shape characteristics are provided in the injection molds and associated with each mold is a resettable indicator designating the particular type of cavity presently installed in that mold.

Abstract: A mechanism for locking two mold parts together includes a cylindrical tie rod securely mounted on one mold part and having a circumferential groove therein. A cylindrical collet sleeve is rigidly mounted on the other mold part and has a plurality of axially extending, circumferentially spaced, resiliently flexible arms at one end. The free end of each arm has an inwardly projecting locking member thereon which the arm resiliently urges radially inwardly. When the mold parts are moved to a closed position, the tie rod is received within the collet sleeve and the locking members become axially aligned with and are urged into engagement with the tie rod groove. An annular collar encircling the tie rod is then moved axially until its inner surface snugly engages the outer surface of the collet arms, thereby preventing radially outward movement of the collet arms.

Abstract: A wheel construction for a wheel primarily used in casters produced under high production conditions. The wheel has an axially extending hole therethrough which is lined with a moldable synthetic resin liner which is mechanically secured to the internal surface of the hole. The liner has axially spaced bearing race receiving structure at opposite ends thereof. An axle is received in the hole and bearings are positioned between the axle and the bearing race receiving structure on the liner to provide for a relative rotation between the axle and the wheel.

Abstract: A mechanism for locking together two mold sections includes one or more lock elements rotatably mounted on one of the mold sections, and a respective cylindrical tie rod for each lock element mounted on the other mold section. Each lock element has a cylindrical opening therethrough along its axis of rotation, and a plurality of lock balls disposed in recesses in the surface of the opening so as to form radially inwardly extending hemispherical projections on said surface. Each tie rod is of a diameter slightly less than that of the corresponding cylindrical opening in the lock element, such that the tie rod is axially slidably receivable within the opening. The surface of each tie rod has a plurality of longitudinal guide grooves radially aligned with the lock balls in the surface of the opening, and each lock ball is slidingly received in a guide groove when the tire rod is slidably disposed in the opening. Intersecting each guide groove at substantially a right angle is a lock groove.

Abstract: A wheel construction including a rigid circular disk having a hole therethrough in the approximate center thereof. A bearing structure housed in a flexible sleeve is resiliently supported in the hole to facilitate a rotation of the disk about a defined axis of rotation. An annulus of moldable synthetic resin material is fixedly secured to the peripheral surface of the disk. The annulus has a rigid characteristic and the periphery thereof defines a tread mounting surface. An annular tread made of moldable synthetic resin material is fixedly secured to the tread mounting surface on the annulus. The tread has an outer diameter that is precisely concentric with the axis of rotation of the wheel. The materials of the tread and of the annulus are compatible with each other such that the tread becomes bonded to the annulus upon a molding thereof around the peripheral surface of the annulus.

Abstract: A wheel construction having bearing means therein defining an axis of rotation. The bearing means is housed in an elastomeric sleeve having an elastic compressibility characteristic. A pair of identically shaped metallic stampings, each having a central cylindrical shell part axially aligned with the other, is provided for housing the bearing structure therein. Each of the stampings has a surface portion intermediate the central cylindrical shell part and the outer periphery thereof, which are coextensive with a central plane through the wheel construction perpendicular to the axis of rotation. The axially aligned cylindrical shell parts engage at least a portion of the elastomeric sleeve of the bearing structure. An annulus of moldable synthetic resin material is fixedly secured to the peripheral surface of the pair of metallic stampings to hold the cylindrical shell part and the surface portions in axial alignment.

Abstract: A severing device for use in a semiautomatic machine for facilitating the wrapping of an article with thermoplastic film material. The device is designed as an adapter to fit into a presently known machine to permit the removal of the hot wire presently used in such machines for severing the film and to replace such hot wire by a mechanical device for this purpose whose location and operation will not appreciably, if any, require alteration of the manual sequence previously known for effecting such wrapping. The device includes a knife and knife bed assembly which is relatively movable by electrical means. At least one limit switch is positioned adjacent the meeting zone of the knife and knife bed assembly so that upon movement of the thermoplastic film downwardly by the same motion as previously placed same against the hot wire for severing, the film will contact and actuate the limit switch and thereby actuate the knife and knife bed assembly for effecting such severing.

Abstract: An improvement in a bearing retainer construction for use with a bearing apparatus having a king pin for use with a swivel caster. The swivel caster has a swivel plate with a central opening therethrough. A pair of annular bearing ball retainers are disposed upon opposite sides of and spaced from the swivel plate. A plurality of bearing balls are disposed between the retainers on opposite sides of the swivel plate for snug rolling engagement with the retainers and with the swivel plate. The king pin is received in openings through the annular bearing ball retainers and has retaining structure thereon to prevent relative axial movement between the retainers and the king pin. A positive mechanical securement is provided between the pair of bearing ball retainers and the king pin to prevent a relative rotation between the bearing ball retainers and the king pin.

Abstract: An indexing mechanism having a base and a cyclical drive unit mounted on the base and connected through a connecting member to a driven member which is supported on and for movement relative to the base. The connecting member has a coupling arrangement thereon which is movable into and out of engagement with the driven member. A control is provided for effecting a simultaneous (1) coupling by the coupling arrangement of the drive member to the driven member and (2) driving of the driven member by the drive member in one direction and a simultaneous uncoupling of the coupling arrangement to (1) uncouple the drive member from the driven member and (2) to drive the drive member in an opposite direction relative to the driven member.

Abstract: Bearing assembly for a wheel primarily for use in casters produced under high production conditions. The bearing is characterized by the provision of a solid shaft with staked ends in association with a resilient seal all arranged for producing a bearing capable of inexpensive manufacture under high production conditions, but also a bearing having close tolerances and thereby capable of long and accurate operation.

Abstract: A method and apparatus for assembling a bearing assembly having bearings therein in a wheel having a hole in the center thereof of a diameter greater than the outer periphery of the bearing assembly. A plurality of molds are provided on a turntable and are indexed between selected positions as the turntable rotates about its axis of rotation. Each of the molds on the turntable has two alignment devices therein, one alignment device being provided for aligning the axis of rotation of the bearing assembly so that it is coaxial with the central axis of the other alignment device. The other alignment device supports the wheel to effect a placement of the center of the outer diameter of the wheel in coaxial relationship with the axis of the one alignment device. A nozzle is provided on the mold and has inlets or orifices to the mold which are aligned with the spacing between the outer periphery of the bearing assembly and the wall surface of the hole in the wheel.

Abstract: A device for use with a bearing construction for a swivel caster mountable on a caster mounting plate and including a yoke having a swivel plate pivotal about a pivot axis. A securing device is provided for securing the yoke to the caster mounting plate. The bearing construction is composed of a ball bearing retaining structure which normally abuts against the underside of the caster mounting plate. An elastomeric member is mounted between the bearing construction and the caster mounting plate. The elastomeric member has a compressible characteristic sufficient to maintain the caster firmly connected to the mounting plate while simultaneously being capable of yielding to a sufficiently large force applied to the yoke to permit a relative movement between the mounting plate and the yoke to thereby prevent permanent deformation to the yoke when an abnormally high force is applied thereto.

Abstract: A wheel construction having a wheel with an axially extending hold therethrough and having a first diameter. A preassembled bearing housing having a second diameter less than the first diameter is located inside the hole of the wheel. The axis of the bearing housing is concentric with the outside diameter of the wheel. The difference between the first and second diameters defines a spacing therebetween. A moldable synthetic resin material fills the aforesaid spacing and effects a securement of the bearing housing to the wheel.

Abstract: Bearing assembly for a wheel primarily for use in casters produced under high production conditions. The bearing is characterized by the provision of a solid shaft with staked ends in association with a resilient seal all arranged for producing a bearing capable of inexpensive manufacture under high production conditions, but also a bearing having close tolerances and thereby capable of long and accurate operation.