Abstract:
A control system for an elastomer extrusion and application apparatus (10,16) including an extrusion rate measuring device (60,200) for receiving a ribbon (12) of extruded elastomer and for providing a signal representing the rate of extrusion, a drive (18) for moving an article (14) to have the ribbon of extruded elastomer applied thereto in a predetermined path, an applicator (16,20,22) along the path for receiving the ribbon and applying the same to the article, a resolver (176) connected to the applicator for providing a signal representative of the rate of application of the ribbon to the article, and a control (FIG. 5) for controlling the speed of the article drive including a circuit for receiving the signals and adjusting the speed of the drive to match a desired proportion between the rate of extrusion and the rate of application.
Abstract:
Uniformity in weight per unit length of continuously extruded tire tread stock is improved by measuring a dimension thereof such as thickness in the tread stock between the extruder die face and the conveyor and controlling the speed of the conveyor in response to deviations from an arbitrary norm of the dimension. A laser beam measuring device for measuring thickness variations in the tread stock before it reaches the conveyor and while the tread stock remains dimensionally unstable following its extrusion.
Abstract:
A lightweight plastics extruder is disclosed which can be used with particular benefit in the preparation of structures wherein a foamable plastic is extruded in a desired location and the extruder moved as foam material is deposited.
Abstract:
An extrusion apparatus, having two die members which are moved relative to one another to extrude a plurality of spaced strands of plastic material in one direction and a plurality of spaced strands in a second direction to form an integral net or net-like structure is operated by generating a first electrical signal having a wave form correlated to a desired motion of the die members, monitoring the actual motion of the die members and generating a second electrical signal having a wave form corresponding thereto, comparing the first and second signals and generating a variable third signal adjusted to compensate for detected differences between the first and second signals, and transmitting the third signal to a torque motor-servo valve combination which controls flow of oil to a hydraulic cylinder piston assembly operatively connected to one or both of the die members for carrying out the desired motion thereof. The motion is carried out with a high order of precision and reproducibility enabling the extrusion of a wide variety of sizes and shapes of plastic net or similar structures.
Abstract:
The operation of an extrusion machine is controlled to obtain a constant cross section in the extrudate without the need to make measurements upon it. The machine is fed by a controlled feeding device which discharges into a reservoir that has a capacity sufficient to ensure that the machine is choke fed, and the reservoir is provided with means, such as a narrow neck, to amplify variations in the level so that unacceptable changes are immediately indicated. Signals representing a rate of feed to the reservoir and the line speed are obtained and the relationship between the feed rate and the speed of the machine and between the feed rate and the line speed are adjusted respectively to maintain a constant level in the reservoir and to establish a constant relationship so that the rate of extrusion of material is kept constant.
Abstract:
Three-dimensional printer fabrication is improved by receiving a digital model of an object specifying two or more different build materials, prioritizing the different build materials with a ranking, identifying exclusive locations where a surface layer of the object has one of the build materials, generating an external structure for the object according to one or more design rules, matching a first build material of the external structure to a second build material of the object at each of the exclusive locations, the matching based on at least one shared property of the materials, generating tool instructions for fabricating the object and the external structure, the tool instructions including one or more selections between the first build material and the second build material based upon the ranking and the matching, and controlling the three-dimensional printer according to the tool instructions to fabricate the object and the external structure.