Patent Application
20060055086
In the golf ball manufacturing process, it is common practice to form the cover of the golf ball using injection molding. A mold comprising a pair of parallel plates containing opposed hemispherical cavities is used to form a spherical cavity within which a fluid thermoplastic material is supplied around a golf ball core. Dimples on the finished golf ball are formed by protrusions in the mold cavities.
After the thermoplastic material sets, the plates are separated and the golf ball is removed from the cavity. The protrusions in the cavities impede the removal of the molded golf ball, and, therefore, it is common practice to provide ejector or knockout pins in the cavity of the mold plates which eject the ball out of the mold. A major drawback to the use of ejector pins is that the pins blemish the outer surface of the ball. Another drawback is that the channels within which the pins move become clogged with molten thermoplastic material.
The present invention relates to an apparatus for extracting molded golf balls from an upper or lower mold cavity without the use of ejector pins, thereby eliminating surface imperfections and simplifying the operation of the mold apparatus.
Accordingly, it is a primary object of the present invention to provide a mechanism to remove a molded golf ball from an injection mold without the use of ejector or knockout pins. The extraction mechanism includes a frame on which is mounted at least one gripping mechanism which has a central axis. The gripping mechanism includes a plurality of radially spaced gripping fingers with their longitudinal axes parallel to the central axis of the gripping mechanism. The central axis of the gripping mechanism is aligned with a central axis of the molded golf ball. The gripping fingers are displaced laterally toward the central axis with sufficient force to partially compress at least the golf ball cover so that the ball surface clears the protrusions in the golf ball mold when the frame is moved away therefrom. The gripping fingers are subsequently displaced away from the central axis, whereby the golf ball is released so that it may return to its original configuration. The gripping fingers may be made of any material sufficient to withstand the forces necessary to compress the molded golf ball without marring the surface of the ball, and may also be contoured to match the curvature of the golf ball or the aerodynamic surface pattern of the ball.
According to a further object of the invention, the gripping fingers are designed such that the force applied to the golf ball is equally spaced about the central axis, thereby reducing the possibility of deforming the molded golf ball.
Other objects and advantages of the invention will become apparent from a study of the following specification when viewed in the light of the accompanying drawings, in which:
Referring initially to
The prior art method suffers from a number of drawbacks. First, if the force applied to the golf ball by the ejector pins 16 is set too high, the molded golf ball may be damaged. Furthermore, thermoplastic material may remain in the voids between the lower plate 10 and the ejector pins 16, which clog the pins or otherwise cause imperfections in the ball surface.
Referring now to
The robotic arm 20 is connected with a motor 34 whose operation is controlled by a controller 36. The controller controls the operation of the motor to position the frame as will be developed in greater detail below. In lieu of a robotic arm, other manipulators known in the art such as air cylinders, mechanical linkages and the like may be used to position the frame between the mold plates.
A plurality of gripping mechanisms 38 are connected with the frame. As shown in
As shown more particularly in
The gripping fingers 42 are designed to grip only the exposed portion of the molded golf ball. Thus, the fingers preferably include a contoured surface 42a which conforms to the surface contour of the golf ball 32. The fingers are made of any rigid durable material such as metal or synthetic plastic. The contoured surface of each gripping finger may be smooth or roughened or may be coated with a material which assists in gripping the golf ball surface.
After the cover layer has been molded onto the golf balls in the golf ball mold 26, the mold plates are separated. The controller moves the multi-axis robotic arm to position the frame 18 adjacent to the molded golf balls in the mold plate cavities with the gripping mechanisms aligned with the associated golf balls. The frame is then moved to position the gripping fingers around the corresponding golf ball as shown in
The controller 36 then controls the robotic arm to move the frame away from the mold 26, thereby extracting the balls from the mold cavities. The frame is then moved to a receptacle. When the gripping fingers are displaced away from the central axis, each gripping mechanism releases its golf ball which drops into the receptacle. Once released, each golf ball expands back to its normal configuration. The golf ball surface does not contain any deformations or imperfections since no ejector pins are used during the extraction process.
In most instances, when the upper and lower mold plates are separated, the golf balls are retained in the lower mold plate. However, in some instances, one or more balls may be retained in the cavities of the upper mold plate. The versatility of the invention can accommodate either situation by positioning the frame with the gripping fingers facing the plate in which one or more balls are retained and actuating the gripping fingers as described above to extract the golf balls therefrom.
In an alternate embodiment (not shown), a small hand-held frame having a single gripping mechanism connected therewith can be manually positioned between the plates for extraction of at least one golf ball. The gripping mechanism includes gripping fingers as set forth above which can be operated under pneumatic or hydraulic pressure to displace the fingers to grip the exposed surface of the ball. When the ball is compressed and freed from the cavity, the frame and gripping mechanism are withdrawn from between the mold plates and manually positioned adjacent a receptacle, and the golf ball is released for deposit therein.
While the preferred forms and embodiments of the invention have been illustrated and described, it will be apparent to those of ordinary skill in the art that various changes and modifications may be made without deviating from the inventive concepts set forth above.
