Patent Application
20070082078
The present invention relates generally to injection molding and deals more particularly with a measuring fixture for measuring plastic parts produced by injection molding.
In the plastic injection molding field, it is necessary to inspect plastic injection molded parts at several stages during the development and production process. In order to be inspected, the plastic injection molded part has to be placed in fixtures to control the correct orientation within the measuring machine. In the past, for each new plastic injection molded part undergoing the development and production process, several measuring fixtures had to be produced to hold the part in different orientations. Accordingly, it would be a great advantage to provide a universal measuring fixture which could hold the injection molded parts in a wide range of orientations within the measuring machine.
It is an object of the present invention to provide a novel measuring fixture for measuring injection molded parts.
It is also an object of the present invention to provide a simple and inexpensive means for measuring injection molded parts.
It a further object to provide such an measuring fixture which may be readily and economically fabricated and will enjoy a long life in operation.
It has now been found that the foregoing and related objects can be readily attained in a novel measuring fixture for use in holding an injection molded part in various orientations in a measuring machine. The measuring fixture comprising a base, an upstanding structure mounted on the base for supporting a part holding component in various orientations and a part holding component mounted on the upstanding structure in various orientations and adapted to mount an injection molded part.
Desirably, the measuring fixture has two additional upstanding structures mounted on the base for supporting the part holding component in various orientations. The first upstanding structure is adapted to support the part holding component with the longitudinal axis in a horizontal orientation while the second upstanding structure is adapted to support the part holding component with the longitudinal axis in a vertical orientation and the third upstanding structure is adapted to support the part holding component with the longitudinal axis in a forty five degree angle orientation to horizontal.
According to the invention, each upstanding structure includes at least one recess for mounting the part holding component on the upstanding structure in various orientations. The part holding component has at least one octagonally shaped mounting portion dimensionally sized for insertion in the at least one recess for mounting the part holding component on each upstanding structure in various orientations.
In still other features of the invention, at least a portion of the part holding component is transparent for purposes of backlighting and at least a portion of the upstanding structure is cutout for purposes of illumination of the injection molded part during measurement.
Ideally, the upstanding structure includes retaining devices for temporarily securing the part holding component in assembly with the upstanding structure. These retaining devices for temporarily securing the part holding component in assembly with the upstanding structure can be spring loaded detents.
The invention will be fully understood when reference is made to the following detailed description taken in conjunction with the accompanying drawings.
Turning now to the drawings and considering the invention in further detail, a measuring fixture is illustrated therein and generally indicated by the reference numeral 10. The measuring fixture is designed for holding injection molded parts 12A, 12B during inspection thereof in a measuring machine (not shown). The measuring fixture 10 has a base 14 which is adapted to be mounted in the measuring machine. Extending upwardly from the base 14 are three mounting devices generally indicated by the reference numerals 16, 18, 20 which permit measuring the injection molded parts 12A, 12B in a range of orientations, e.g., 0°, 45°, 90° and 180°. The injection molded parts can be components for cellular phones such as device covers.
The first mounting device 16 has two spaced apart, equally sized stanchions 30A and 30B with defined angled collar recesses 32 on their inner facing sides. Seated in the angled collar recesses 32 is a universal part holding component 34 for mounting the injection molded parts 12A, 12B on either side using screws (not shown). The universal part holding component 34 has a metal frame 35 with a part specific mounting plate 36 attached thereto by screws 37. The part specific mounting plate 36 is made of transparent polycarbonate plastic to allow application of correct backlighting within the measuring machine. The universal part holding component 34 also has spaced apart octagonal end extensions 38 extending from the ends thereof to permit the universal part holding component 34 to be accurately placed in the angled collar recesses 32 in eight different angled positions by simply lifting the universal part holding component 34 from the angled collar recesses 32, rotating the universal part holding component 34 until the desired position is reached and then reinserting the same into the angled collar recesses 32 until it is seated therein. In each of the eight positions, the longitudinal axis of the universal part holding component 34 is maintained in a horizontal orientation.
If it is desired to maintain the longitudinal axis of the universal part holding component 34 vertically, the second mounting device 18 can be used. The second mounting device 18 has two stanchions 40A, 40B mounted on the base 14. The stanchion 40A lies on the base 14 and has a generally rectangular form. The stanchion 40A also defines angled U-shaped recess 42 and has a pair of spring loaded detents 44 (
Using the third mounting device 20, the longitudinal axis of the universal part holding component 34 can be held at a forty five degree (45°) angle. The third mounting device 20 has two stanchions 60A and 60B mounted on the base 14. The stanchion 60A extends upwardly from the base 14 and has forty five degree (45°) angled slot 62 cut therein. A pair of spring loaded detents 64 extend into the slot 62 to removably retain the octagonal end extension 38 of the universal part holding component 34 therein. The stanchion 60B has an upstanding portion 66 spaced from the stanchion 60A and a cantilevered portion 68 extending outwardly toward the stanchion 60A. The upstanding portion 66 is provided with a cutout 70 (
While three universal part holding components 34 are illustrated in
In use, the measuring fixture 10 allows the measurement of injection molded parts 12A, 12B in a wide range of orientations within the measuring machine. The universal part holding component 34 can be positioned in any of twenty four (24) positions within the measuring fixture 10 as required by the features of the injection molded parts 12A, 12B which need to be measured. The transparency of the part specific mounting plate 36 allows the application of the correct backlighting within the measuring machine. Accordingly, the present invention provides an advantage over the prior art by making the measuring process easier. A further advantage is realized from the reduced manufacturing cost since the measuring fixture 10 can be universal and reusable for all different types of injection molded parts as only the part specific mounting plate 36 need be replaced for each project.
The preferred embodiment described above admirably achieves the objects of the invention. However, it will be appreciated that departures can be made by those skilled in the art without departing from the spirit and scope of the invention which is limited only the following claims.
