Abstract:
A fluid transfer assembly comprises two parallel fluid transfer paths and a shared, linear path actuator for providing positive sequencing of input and output valves of both paths. Corresponding valves of the two paths share a lever assembly which is rotated between first and second positions by reciprocal movement of the liner path actuator.

Description:
TECHNICAL FIELD 
     Valve assemblies for transfer of fluids from an input port to an output port by way of a transfer chamber. 
     BACKGROUND OF THE INVENTION 
     There are a variety of commercial operations wherein a fluid, e.g., a resin which is available in a source volume e.g., a few gallons, is moved under a first pressure to fill a closed dispensing reservoir; and then dispensed from that reservoir to a work site under carefully controlled conditions i.e., pressure and rate of output flow. The injection of a two component epoxy resin into structural cracks of a concrete structure to effect a permanent repair of the structure is an illustrative example of such commercial operations. A dispenser which meters and mixes the two components i.e., base resin and catalyst comprises a pair of transfer assemblies for handling the two components and a common output region where the outputs of the assemblies are mixed and delivered to the work site. Such a prior art dispenser is the CD3-A Dispenser which is marketed by Lily Corporation of Aurora, Ill. Each transfer assembly comprises: an input port, an input valve, a transfer chamber, a transfer input-output port, an output valve, and an output port. The input valves of the two assemblies are positioned opened and closed by a common input valve actuator; and similarly the output valves of the two assemblies are controlled by another common output valve actuator. In the CD3-A dispenser, the actuators are operated in sequence in accordance with locally produced control signals. It is important that the input valves are fully closed before the output valves are opened; and, upon completion of the dispensing of the mixture to the work site, the output valves must fully close before the input valves are opened. If the input and output valves remain simultaneously open, an improper mixture e.g., a mixture having a higher than normal catalyst level can reach the work site. 
     DISCLOSURE OF THE INVENTION 
     In accordance with my present invention: a fluid transfer assembly comprises: an input port, an input valve, a transfer chamber, a transfer input-output port, an output valve, and an output port; first and second lever assemblies, coupled respectively to the input and output valves, for respectively adjusting the input and output valves, shared mechanical actuator means for positioning the lever assemblies in fixed transfer sequences such that the input and output ports are precluded from being in simultaneous communication with the transfer chamber, and means for controlling the actuator means. 
     Advantageously, the use of a single actuator assures positive sequencing of states of the input and output valves and thus eliminates any possibility of direct communication between an input port and an output port. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIGS. 1, 1A and 1B are top and sectional views of a fluid transfer assembly in the &#34;input state&#34; of the assembly; 
     FIG. 1C is a top view of a lever assembly of FIG. 1; 
     FIG. 1D is an edge view of a lever assembly of FIG. 1; 
     FIGS. 2, 2A and 2B are top and sectional views of a fluid transfer assembly in the &#34;output state&#34; of the assembly. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 is a top-view diagram of a dual path fluid transfer assembly in accordance with my invention. The assembly of FIG. 1 comprises a first transfer path assembly 110, a second transfer path assembly 120 and a control assembly 140. The lower transfer path assembly 110 comprises an input valve module 111, a transfer module 112 and an output valve module 113. The second transfer path assembly 120 comprises an input valve module 121, a transfer module 122 and an output valve module 123. 
     In FIGS. 1, 1A and 1B, valves 151 and 152, levers 162 and 163 and actuator rod 143 and actuator 144 are all shown positioned in the input state of the fluid transfer assembly of FIG. 1. The cross sectional views of FIGS. 1A and 1B are schematic in form to represent the functioning of levers 162, 163 and the related valves 151 and 152. Accordingly, not all mechanical detail has been included in FIGS. 1A and 1B; and in FIG. 1A, the levers 162 and 163 are shown in full outline without regard for the presence of the actuator rod 143. 
     The general construction of the lever assemblies 162 and 163 is shown in FIGS. 1C and 1D. The lever 171 of FIG. 1C comprises a through hole 175 for receiving an attached shaft 178, 179 which is operatively coupled to a valve in each transfer path assembly. In the illustrative embodiment of my invention, the unitary lever 171 comprises a first lever arm 173 and a second lever arm 174 which are disposed at 90° from one and another. The surfaces of the arms 173 and 174, which are nearest to each other, provide camming surfaces for operatively engaging the operator member 144 of the actuator rod assembly. As illustrated in FIG. 1D the lever arm 174 is solid and the lever arm 173 is bifurcated to permit the actuator rod 143, as illustrated in FIG. 1, to pass between the legs 176 and 177 of FIG. 1D. 
     In the input state of the transfer path assemblies, the valve 151 is in the open position to permit fluid communication between input port 115 and transfer chamber in transfer assembly 112, and input-output port 114. The valves in transfer assembly 120 are similarly positioned. 
     The lever assembly 162 of FIG. 1A is coupled to a shaft which in turn is coupled to the valves in input valve modules 111 and 121. Similarly, lever assembly 163 of FIG. 1A is coupled to a shaft which in turn is coupled to valves in valve modules 113 and 123 of FIG. 1. 
     In FIG. 1A, lever assemblies 162 and 163 have been placed in the &#34;input state&#34; by movement of actuator rod 143, actuator 140, and plunger 142 from their fully withdrawn positions, as illustrated in FIG. 2A, to their fully extended positions. 
     The dual path fluid transfer assembly of FIGS. 1 and 2 has two stable states, namely, the &#34;input state&#34; and the &#34;output state&#34;. In the &#34;output state&#34;, the positions of valves 151 and 152, levers 162 and 163, actuator 144, actuator rod 143 and solenoid plunger 142 are shown in FIGS. 2, 2A and 2B. The plunger 142, of solenoid 141, is selectively moved between the fully extended position shown in FIG. 1A and the fully withdrawn state shown in FIG. 2A by selectively introducing air at ports 145 and 146. 
     For both directions of travel of actuator arm 143 and actuator 144, input valve 151 and output valve 152 are never simultaneously open to permit communication between the input port 115 and output port 116. As the transfer assembly is cycled from the input state to the output state, valve 151 is closed and only thereafter output valve 152 is opened. Similarly as shown in FIG. 2 as the transfer assembly is cycled from the output state to the input state, valve 152 is first closed and only thereafter valve 151 is open. 
     In the illustrative embodiment of my invention, the actuator 144 is moved bidirectionally between the &#34;input&#34; and &#34;output&#34; states of the transfer mechanism by operation of pneumatic solenoid 141. While this arrangement is the preferred embodiment of my invention, other mechanical arrangements can be used to achieve the desired reciprocating movement of actuator 144. For example, solenoid 141 can be either an electric or hydraulic solenoid. 
     The invention has been described with particular attention to its preferred embodiment; however, it should be understood that variations and modifications within the spirit and scope of the invention may occur to those skilled in the art to which the invention pertains.