1. Field of the Invention
This invention relates generally to separatory funnel devices having valve structure therewith for accurately controlling the dispensation of liquid therefrom.
2. Description of the Prior Art
A common problem with known devices for dispensing and separating liquids using what is known as "separatory funnels" is that in order to transfer liquid from one container to another, the pressure of the two containers must be equalized. Oftentimes air must be allowed to escape from the second container through the funnel structure. To do this a separate channel must be provided so as not to interfere with the flow of liquid from the funnel or regulatory device. In known type devices this comprises a separate tube commonly termed "a side arm" which is attached below the control valve to near the top of the funnel so as to be above the liquid level therein. This tube is generally made of glass. Such a side arm is relatively expensive to manufacture and attach, is easily broken, and quite impossible to clean.
Another problem with known type devices for use as separatory funnels is that the valve structure thereof is basically an on-off valve, rather than a flow control valve. Thus, while the liquid flow can be turned on and off, it is generally quite difficult to accurately and precisely regulate the liquid flow and/or accurately and precisely determine the amount of fluid flow therefrom.
Existing prior patents which may be pertinent to the present invention are as follows:
______________________________________ 272,379 J. W. Fenner 2/13/1883 2,608,993 H. Andrews 9/2/52 2,670,008 G. Kopp 2/23/54 3,257,170 M. Marcus et al 6/21/66 4,080,965 T. E. Phillips 3/28/78 4,230,300 H. L. Wiltse 10/28/80 ______________________________________
These patents show valve structure for controlling the dispensing of liquid from a container. The Fenner patent has an oil-feed regulating stem b with an oil flow slot therein c. However, this device does not have structure for permitting air or gas flow in a path separate from the oil flow path. The Andrews and Kopp patents show manually adjustable control valves provided with manually actuable structure for controlling the liquid flow past the valves. The Marcus et al patent is for liquid separatory apparatus wherein the valve plug 26 has a transverse bore 36 for liquid flow therethrough and bores 46, 48 for air flow therethrough. However, the overall structural arrangement of this device is entirely different from that of the present invention. The Phillips patent shows an in-line valve assembly for controlling the flow of blood between two containers. The cannula element can be positioned to either a closed position or a flow permitting position. The Wiltse patent shows a flow metering and shut-off valve wherein the valve has spaced seals so that contamination cannot be transferred through the structure when fluid is being introduced into a living person. These patents all show various valve flow and control structures; however, none of the known prior art devices offer the new and novel features of the present invention.