Machine for continuous pumping of plastic materials

In a machine for the continuous pumping of plastic materials:

• an elongated, open-top cabinet, having a receptacle supported therein at one end thereof,
• said receptacle having dual, laterally spaced sets of axially aligned inlets and outlets below the open top of the cabinet which communicate the receptacle with internal and external portions of the cabinet, respectively;
• a materials supply hopper mounted above said receptacle for feeding materials downwardly into the latter through the open top of the cabinet;
• a pair of alternately reciprocable, pump chamber-defining sleeves in the cabinet each aligned with a corresponding inlet and outlet and movable through its inlet between a rectracted position substantially outside of the receptacle and an extended position sealing off the hopper from further materials supply;
• a plunger for each of said sleeves, respectively,
• said plungers being alternately reciprocable through their corresponding sleeves for pushing successive charges of materials from alternate ones of said outlets when their sleeves are extended and loaded with materials from the hopper;
• an operating and control pack in the cabinet behind the plungers and sleeves for moving the same through their respective operating cycles in timed relationship with one another so as to effect substantially continuous pumping of materials from the machine,
• said pack including a power device for each of said plungers and each of said sleeves, respectively;
• a plurality of limit switches for controlling reciprocation of the plungers and their sleeves;
• actuating structure associated with said plungers and sleeves for engaging and operating said switches during reciprocation of the plungers and sleeves;
• and a frame common to said plungers, said sleeves, said power devices, said switches and said structure;
• and
• means mounting said frame for vertical swinging movement about a horizontal axis between lowered and raised positions,
• said frame joining said plungers, said sleeves, said power devices, said switches and said actuating structure together for swinging thereof as a unit about said axis for locating the plungers and sleeves in alignment with their respective inlets when the frame is in said lowered position and for projecting the plungers and sleeves accessibly through the open top of the cabinet when the frame is in said raised position,
• said cabinet including an open rectangular section behind said receptacle defining a longitudinally and transversely unobstructed cavity extending between the rear wall of the cabinet and the receptacle on the one hand, and the two lateral sides of the cabinet on the other hand,
• said cavity receiving said pack, said plungers and said sleeves for movement thereof about said axis between said positions,
• said frame including a front transverse plate spanning said cavity from top to bottom and from side to side thereof between the pack and said plungers and sleeves so as to subdivide the cavity into a pair of unobstructed subcavities on opposite fore-and-aft sides of the plate when the plungers, sleeves and power pack are in said lowered position whereby to facilitate cleanup of the machine.