Controlled pollution control valve by-pass device for carbureted internal combustion engine

A fuel saving device for a carbureted engine having a pollution control valve comprising a by-pass duct adapted to convey gases from the crankcase around the pollution control valve directly to the carburetor and a valve in the duct controlled by the manifold vacuum to open the valve at lower pressure in the manifold and close it at less depressed pressures.

BACKGROUND AND SUMMARY OF THE INVENTION 
This invention pertains to devices adapted to increase fuel efficiency in a 
carbureted engine, and more specifically to a device adapted to by-pass 
the pollution control valve (PCV) now required of a normal automobile 
engine and thereby to increase the flow of gases from the crankcase of the 
engine to the engine intake system downstream of the mixing area in the 
carburetor. 
The current requirements of the use of emission controls on automobile 
engines has resulted in a reduction in fuel efficiency on such engines. 
The high cost of gasoline to be used in such engines has made maximum fuel 
efficiency desirable. The emission control commonly in use is the PCV 
system which injects gaseous material from the crankcase of the engine 
into the intake system of the engine at a point just downstream of the 
carburetor. The valve called the PCV simply controls the amount of flow. 
Many devices have been proposed to inject additional fresh air into the PCV 
line entering the intake system. Some have been hand controlled, other 
electrically controlled. 
My device is somewhat similar to the fresh air injection devices, although 
it provides better efficiency. Instead of introducing fresh air and still 
using the PCV with the high pressure drop across the valve, I provide a 
by-pass system allowing substantially higher flow from the crankcase at 
times when the intake manifold vacuum is highest (lowest pressure). I do 
this by means described hereafter and illustrated in the following figures 
.

DESCRIPTION 
Briefly my invention is a by-pass means for the PCV line in a carbureted 
engine having control means in the by-pass by which the PCV is by-passed 
only when the manifold vacuum is greatest. 
More specifically, and referring to the drawings, I build my device in 
conjunction with the conventional PCV 10 adapted to open into the 
crankcase of an automobile engine. Instead of having the valve directly 
connected to the crankcase, I provide a "T" fitting 11 in the line. One 
end 12 of the "T" is adapted to be connected to the customary PCV outlet 
from the crankcase (not shown). 
The outlet from the PCV is, in my device, a tube 13 connected to a pipe 14 
or the like which provides the connection to the engine intake system 
downstream of the carburetor as is well known in the art. 
By using the "T" 11, I can by-pass the PCV 10 and duct the gases entering 
the end 12 of the "T" through the leg 15 and through the pipe 14 directly 
into the intake system. Such direct connection is not satisfactory, 
because it completely negates the effect of the PCV. However, I have 
discovered that the principal inefficiencies caused by the PCV occur when 
the greatest vacuum exists in the intake manifold. Therefore, I provide a 
butterfly valve 17 enclosed in a body 18 inserted into the by-pass line. 
The valve 17 is controlled from the exterior by a lever 19 which can work 
back and forth as illustrated in the two positions shown in FIG. 3. The 
valve is biassed to a normally closed position by means of a tension 
spring 20 engaged between the lever 19 and a bracket 21 which may be fixed 
to the body of the "T" fitting 11. Movement of the lever is controlled by 
a vacuum cylinder device 22 including an operating member 23 attached to 
the lever 19. 
The cylinder device 22 is of the type in which the member 23 is drawn into 
the cylinder by higher degrees of vacuum in the cylinder. The vacuum in 
the cylinder is drawn through a tubular inlet 24, which in my device is 
connected to the same vacuum line that controls the spark advance through 
the position of the distributor in a manner well known in the art. 
Thus when the manifold vaccum is greatest (pressure lowest), the vacuum is 
drawn in the cylinder 22. This results in the pulling of the member 23 
into the cylinder and the opening of the valve 17. Gases from the 
crankcase can then bypass the PCV and be recycled directly into the intake 
system. My tests indicate that such by-pass substantially reduces fuel 
consumption at such times and thus provides real increases in fuel 
efficiency of the automobile engine so equipped. 
In order to provide for more flexibility I may also provide a manually 
adjustable butterfly valve 25 in the body 18. Although I have illustrated 
this valve downstream of the valve 17, it is clear that it could be 
upstream as well. A control handle 26 may be used to control the position 
of the valve. This type of structure may best be used if the device is to 
be sold as an attachment for use with various sizes and types of engines 
to provide for the best setting for each individual engine. 
It is also envisioned that a valve such as the valve 25 might be controlled 
by the temperature of the gas flowing through the body 18 in a manner well 
known in the art. Such a control might be useful if it were desired that 
the by-pass only be opened after the engine is warmed up. It is obvious 
that the heat sensor of any heat controlled valve must be upstream of the 
butterfly valve 17.