摘要:
In accordance with a preferred embodiment of this invention, a linear stitching design having improved definition, is embossed onto the surface of a hot, formable plastic sheet and then coated in one operation. The improved definition is achieved by employing a restrained elastomeric anvil to support the sheet during the embossing operation. The elastomeric anvil provides a relatively uniform distribution of pressure on the sheet during the embossing step and urges the sheet into intimate contact with the recessed features on the embossing die surface. Once the sheet is formed but before the embossing die and anvil surface are separated, paint is injected through passages in the embossing die onto the surface of the thermoplastic sheet. The paint is injected under sufficient pressure to force the thermoplastic sheet, which is supported by the elastomeric anvil, away from the die surface; this provides the necessary space to allow the paint to flow onto specified areas of the sheet.
摘要:
An apparatus for producing tires suitable for use on vehicles from elastomers, especially from rubber by injection-molding is disclosed. The apparatus has a multi-part cord defining an inner side of a mold cavity for receiving separately prefabricated reinforcements of the tire. The cord can be reduced in size to define the external periphery by relative displacement of individual parts for the removal of the tire from the mold. The mold core with the reinforcements is inserted into a multi-part injection mold by which the core is completely enclosed.
摘要:
A flexible mold and process is provided for making pots, and the like, the mold comprising a cylindrical-shaped rubber-like resilient member having an annular-shaped cavity contained therein, and an open top. The construction of the mold is such the pressurized air may be introduced into the cavity to move the outer peripheral portion of the mold radially outwardly to release the part being molded. A nail, or similar article may be inserted into the central part of the mold to protrude through the open top of the mold along the central axis thereof. The nail causes a hole to be formed in the bottom of the article being molded which serves as a water hole when flower pots, for example, are being molded, and which also provides a convenient hole through which the releasing pressurized air may be introduced into the mold cavity.
摘要:
Hoop stresses are relieved to eliminate the formation of cracks produced ing the molding of a thermoplastic fitment cover about a support ring structure. Heated plastic is directly molded about the support ring to form any desired cover shape. Hoop stresses created in the cover as the fitment shrinks upon cooling are relieved by means of an interfacing cushion of elastomer. Variation in elastomer configuration provides the flexibility of allowing the elastomer to be "snapped-on" or to be directly molded onto the support ring.
摘要:
A finished plastic-handled brush is prepared by a single molding step involving gateless molding of the brush back by a tunnel-gating and novel punch-pin finishing apparatus and process which eliminates the usual gate stud, and removing the finished brush back and securing tufts of bristles in the face of the brush back to complete the brush construction.
摘要:
A clamp for holding together the portions of a mold used in molding solid objects from a reacting liquid such as polyurethane has a C-shaped frame which is pivotally mounted on a pedestal to swing through an arc. The C-shaped frame of the clamp consists of an integral structure having an upper jaw connected by a column to a lower jaw. The frame supports a bed, crown and platen. The bed and crown are each a plate-like member that is mounted to pivot relative to one of the jaws. The platen is mounted preferably on the bed or lower one of such members. The mold portions are mounted on the crown and platen with the parts being arranged to move so that the mold portion engage and disengage. The invention also includes a method of molding wherein the mold portions are engaged and disengaged by a process that involves pivoting at least one and preferably both of the portions relative to the C-shaped frame.
摘要:
A method for selecting replacement valve stems to replace corresponding defective valve stems including the steps of selecting a set of pattern valve stems representing the replacement stems and employing such pattern valve stems to construct a mold having coded cavities defining the contour of such pattern valve stems. Fluid plastic is then poured into the cavities of such mold while the mold is spun to force such plastic positively into such cavities under the influence of centrifugal force, the valve stem models formed in such cavities then cured and removed from the mold. The coded valve stem models are then collected together on a display board or the like to be displayed in a market area for viewing by customers so a customer desiring to replace a defective valve stem may compare such defective valve stem with the model valve stem to obtain a code designation to indicate the replacement valve stem corresponding with such defective valve stem.
摘要:
A unitary mold for use in casting concrete objects, for example, meter box covers and the like. The mold comprises a one-piece tray molded from flexible polyvinylchloride having a bottom wall and a peripheral sidewall having an external annular flange on the upper end thereof, and a steel ring that is placed on the exterior of the tray prior to casting an object to ensure dimensional stability. The top surface of the bottom of the tray is formed with whatever nonskid or other pattern is desired for the top surface of the cast object, and can include a cavity to receive various pattern inserts for forming lettering, indentations or other formations on the cast object. The inner surfaces of the side walls are tapered inwardly from the lower end to the top thereof, to form side walls on the cast object that taper inwardly from the top to the bottom of said object. To remove the object from the mold, the ring is first removed, and the polyvinylchloride tray is then flexed or stretched as required to free the object.
摘要:
A device for molding a pneumatic tire, by forming a molding cavity between an outer hard mold and a flexible hollow toroidal core, pouring a fluidized tire-forming material in the cavity while applying an internal pressure to the core, and releasing the internal pressure upon hardening of the tire-forming material.
摘要:
Improvements in the O''Driscoll et al. U.S. Pat. No. 3,700,761 composition consisting of regulating critical proportions of PVP, HEMA, MA, EDMA, Water and the first and second stage initiators for producing hydrophilic lens blanks from which reproducible and predictable hydrated lenses are obtained with ratios of acceptance of 95 - 98%, to dimensional standards between the grinding dry and hydrated wet states and with ratios of resisting dimensional change in wet storage of upwards of ninety five percent. Compositions lying outside of the critical ranges of proportions provide lenses which are unpredictable (90% rejection) drift in size and do not provide reproducibility between dry and wet states and thereby create fitting problems. Critical ratios of MA TO EDMA lying between 2.5/3.2 at 15% PVP content down to 1/1 at 28% PVP content provide reproducibility and predictability dry-to-wet and the optimum ratio is 1.5/0.7 at 20% PVP (reagents containing less than 1% water). Further improvement is made in the method of casting and cutting of U.S. Pat. No. 3,700,761, in which there is used a disposable mold of Teflon, high-density polyethylene or of RTV Silicone material with break-away curved bottom which is discarded to provide a convex surface requiring no cutting thereby eliminating many cutting and grinding steps on the conventional hard-lens lathe. Water-soluble medicaments as in Pat. No. 3,700,761 can be added to precision-cut eye bandages by dissolving in H2O and adding a total of 5% H2O to HEMA or the medicament can be used in eye drops, the bandage with 5% added containing 65% H2O instead of 60%.