Automatically operated gate valve for recreational vehicles

This invention is a hydraulic device for operating a gate valve in the drainage line of a recreational vehicle. The device consists of a support plate mounted to the gate valve or drainage line. A hydraulic cylinder with a hydraulic rod is pivotally mounted to the support plate. The hydraulic rod is attached to the gate control rod by means of a pivot arm that is also pivotally attached to the support plate. The device is operating by means of a hydraulic pump, a motor and control means for operating the motor, typically an electrical switch.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to gate valves, and more particularly to 
automatically operated gate valves for use with holding or similar tanks 
for recreational or similar type vehicles. 
2. Description of the Prior Art 
Users of recreational vehicles outfitted with a water closet, tub or shower 
or both, and a kitchen sink are required to discharge the waste and gray 
water from these fixtures into onboard holding tanks that must be 
discharged or dumped into an approved sanitary sewer or septic system 
usually located in a trailer court or camp ground. 
Users of recreational vehicles often find it inconvenient or difficult to 
dump the holding tanks into sanitary facilities because of their own 
physical limitations, bad weather conditions, darkness, etc. Dumping 
typically requires kneeling down and reaching under the vehicle for a 
distance of two to two and a half feet. In this position, the operator is 
off-balance and unable to obtain good leverage to operate a manual gate 
valve. This can be especially troublesome for those of slight build, the 
elderly and the handicapped. Moreover, while operating the gate valves, 
the operator is sure to be contaminated with waste should there be a 
failure in the waste hose, hose connection or hose clamp. In addition, 
gate valve operation can be especially worrisome in strange surroundings 
and especially annoying and frustrating in foul weather or when biting 
insects are at their peak. 
One approach to this problem has been through the development of 
telescoping drain assemblies that are swiveled and telescoped to the 
discharge site such as revealed in Feliz U.S. Pat. No. 3,811,462 and 
Sargent et al. U.S. Pat. No. 4,779,650. Although these inventions attempt 
to solve the piping problem between the discharge line of the vehicle and 
the discharge point, neither of them address the problem of valve control 
since both of these inventions continue to use manually operated valves to 
open and close the discharge lines. 
Kemper et al U.S. Pat. No. 4,214,324 and Perez U.S. Pat. No. 4,693,447 
disclose waste dump valves that are electrically controlled for use in 
aircraft and railroad cars respectively. Hilde, Jr. U.S. Pat. No. 
3,375,025 is directed to a pneumatic valve mechanism for use with a mobil 
system for evacuating and recharging portable commodes. 
Pierson U.S. Pat. No. 3,941,349 is directed toward the development of 
electromechanically actuated gate valves. Pierson's inventions, however, 
have several shortcomings and problems. First, all of Pierson's mechanisms 
for controlling the gate valve are contained within the housing of the 
gate valve itself. As such, it is not possible to convert an existing 
manual valve to a mechanically operated device. All the vehicle owner can 
do is to remove the manual valve and replace it with one of Pierson's 
electromechanically operated valves. Further if the electromechanical 
mechanism of the Pierson valve breaks down, it is impossible to repair it 
with out removing it from the drainage line--a process which requires 
replacement of a portion of the drainage lines in addition to the repair 
or replacement of the valve itself. 
Pierson's solenoid driven valves are spring biased so as to remain in the 
closed position unless the solenoid is electrically actuated. As a result, 
Pierson's solenoid devices must draw current continuously while the 
holding tank is being emptied thereby adding to the cost of operation and 
increasing the potential for failure as a result of electrical short or 
burnout. Such continuous operation also increases the chance for an 
electrical fire. Moreover, Pierson's closed biased solenoid valves do not 
allow the valve to be left in an open position, even by manual operation. 
In many instances this is the preferred position, especially when the 
vehicle has been permanently parked and the drainage line hooked up to the 
sanitary sewer. In such a setting, the drainage line is left open without 
further consideration. Using the Pierson valve, the vehicle user must 
periodically open the gate valve to drain the holding tanks even when the 
vehicle is in a parked mode and connected to a sanitary sewer. Such 
additional operation tends only to shorten the life of the Pierson valve. 
Because Pierson's solenoid valves effectively have only a fully opened or 
closed position, it is impossible to adjust the volume of discharge from 
the holding system. In the event of a power failure, the user of a Pierson 
solenoid valve must resort to manual operation of the valve in order to 
empty the holding tanks. 
Pierson has also developed motor driven direct drive and gear drive valves. 
Such motor driven valves are more complex than the solenoid valves thereby 
increasing the potential for malfunction. Since the drive mechanisms are 
contained within the valve housing, the only way to repair such valves is 
by removing them from the drainage line, which, as we have seen, is costly 
since portions of the drainage line must be replaced along with possibly 
the valve itself. 
SUMMARY OF THE INVENTION 
The present invention overcomes the inconvenience and burden of operating 
the manual valves found on most recreational vehicles, especially in 
inclement weather, strange surroundings, and other environmental 
hostilities which make such valve operation :specially onerous for the 
weak, elderly and disabled. It also overcomes the problems and obstacles 
encountered with the self-contained electromechanically operated valves 
found in the prior art, especially the inability to convert an existing 
manual valve to a mechanical valve, the inability to set the valve to any 
position including fully opened or closed, and the necessity for unneeded 
or prolonged operation under certain conditions that do not justify such 
operation and serve only to add to the cost of operation, reduce the 
operational life time, and increase the risk of electrical short or fire. 
The present invention consists of a hydraulic device that is connected to 
the gate of a gate valve for the purpose of opening and closing the valve. 
The invention can be used to convert existing manual gate valves to 
hydraulically operated valves without removing the existing valve from the 
drainage line of the recreational vehicle (RV). Because it can be mounted 
on the existing valve or drainage line, it can be readily removed for 
repair or replacement without the need to remove the gate valve from the 
drainage line. Although the device can be installed within the gate valve 
housing, it is preferable not to do so for the above mentioned reasons. 
Various additional features of the invention allow the gate valve to be 
stopped at any position between fully opened and fully closed so as to 
adjust the volume of discharge form the holding system. The invention uses 
energy only in moving the valve from one position to another. No energy or 
power is required to hold the valve in any desired position and thus the 
valve will remain in the selected position even when power is lost. The 
invention can be disconnected from the valve to allow for manual operation 
of the valve to any position should the device ever fail or power be lost. 
The valve can be operated from remote locations, typically from within the 
RV and from a control panel located on the exterior of the RV preferably 
in the area of the drainage discharge. The invention can also be provided 
with an indicator such as a light, buzzer, or dial to indicate the 
position of the gate valve. 
The invention is not limited to RVs but can be used in any vehicle having 
holding tanks where it is desirable to control the opening and closing of 
the drainage line from the holding tanks. 
In one basic form, especially useful for opening, closing, or holding a 
holding tank gate valve in any position where the gate valve is located in 
a passage connected to a holding tank of a recreational or similar type 
vehicle, the invention consists of a hydraulic cylinder that has a 
cylindrical housing with a hydraulic rod projecting from the center of one 
end, a way or means for connecting the hydraulic rod to the gate of the 
gate valve and a means for controlling the movement of the hydraulic rod 
into and out of the hydraulic cylinder housing. Typically, the means for 
controlling the movement of the hydraulic rod into and out of the housing 
is a hydraulic pump for pumping hydraulic fluid into and out of the 
housing so as to cause the hydraulic rod to move into or out of the 
housing. A motor is used to operate the hydraulic pump and is, in turn, 
controlled by a switch device. Generally, an electrical motor and an 
electrical switch are preferred, however, it is to be understood that 
there are other means for operating hydraulic pumps such as a hydraulic 
motor and that such a device can be operated by vacuum or air pressure 
switching devices. 
A valve can be placed in the hydraulic line for maintaining the amount of 
hydraulic fluid in the hydraulic cylinder so as to control the position of 
the gate within the gate valve. The opening and closing of this valve can 
be controlled by a suitable means such as a solenoid. 
The motor that is used to move hydraulic fluid into and out of the 
hydraulic cylinder is preferably a reversing motor. When a reversing motor 
is used, the switching means for controlling and operating the motor 
should be capable of operating the motor in either a forward or reverse 
direction. It is desirable to the switching means for controlling the 
operation of the motor to be placed at two or more remote locations. For 
example, it is desirable to have one control means such as a switch panel 
located within the recreational vehicle so that one does not have to leave 
the recreational vehicle to control the opening and closing of the gate 
valve. A second desirable location for the motor switching or control 
means is on a panel located on the outside of the vehicle near the point 
of discharge of the drainage system. In such a location, the user of the 
RV can monitor the discharge operation into the sanitary sewer. 
It is also desirable that the hydraulic means for operating the gate valve 
be capable of being disconnected from the gate valve so as to operate the 
gate valve in the event of loss of power or energy with which to operate 
the hydraulics of this invention. In such a case, the hydraulics can be 
disconnected by means of a locking pin or other such quick disconnect type 
feature. When the hydraulics are disconnected, a handle can be attached to 
the gate rod of the gate valve so as to manually operate the valve. 
Finally, it is desirable to know the position of the gate within the valve. 
This can be achieved by providing a sensing and indicating mechanism for 
determining the position of the gate within the gate valve. The sensing 
mechanism is typically a switch responsive to the position of the gate 
while the indicating means can be a visual indicating means such as a 
light or dial, or an audible means such as a buzzer or bell. 
Another aspect of the invention is a means for externally mounting a gate 
valve hydraulic control device, preferably a hydraulic control device, on 
either the gate valve or the drainage line. This aspect of the invention 
consists of a support plate and a means for fastening the support plate to 
the drainage line or the external portion of the gate valve housing. In 
its simplest form, the fastening means can simply be one or more U-bolts 
that pass around the drainage line and pass through aligning holes in the 
support plate where they are fastened to the support plate by means of 
bolts. For additional stability, a saddle piece conforming to the drainage 
line can be secured to the U-bolt after it passes around the drainage line 
by means of bolts and then the support plate bolted on to the projecting 
ends of the U-bolts. 
In another embodiment, rather than using the saddle piece after the U-bolt 
passes around the drainage line, the support plate may have on its under 
surface one or more projecting tangs having a surface conforming to a 
portion of the circular surface of the drainage pipe. In this embodiment, 
the support plate rests on the drainage line as a result of the downward 
projecting tangs that conform to the drainage line and the U-bolt passes 
around the drainage line up through the apertures in the support plate and 
are bolted to the upper surface of the support plate. 
In another embodiment, a suitable slot can be formed in the downward 
projecting tang that conforms to the drain line and a hose-type clamp 
passed there through and secured around the drainage line. The downward 
projecting tang that partially conforms to the drainage line curvature can 
also be extended sideways (outward) beyond the support plate and the hose 
clamp passed around both the projecting tang and the drainage line and 
fastened around both. 
In all of these configurations, it is to be understood that preferably two 
U-bolts are used and that they are located on both sides of the gate valve 
housing and that, if more than one downwardly projecting tang is used, 
they are located in such a fashion so that the gate valve housing can rest 
between the projecting tangs. It is also to be understood that the U-bolt 
can pass around the drainage line or around the circular boss that is part 
of the gate valve housing that receives the drainage line. 
A hydraulic cylinder that consists of a cylindrical housing with a 
hydraulic rod projecting from one end is attached to the support plate by 
suitable means. Such means can consist of two upwardly projecting, support 
plate tangs with aligning holes. The tangs are positioned so as to receive 
a boss on one end of the cylinder housing that has an aperture in it so 
that the apertures in the tangs and the aperture in the boss align so as 
to receive a pivot pin. The pivot pin is locked into place by any suitable 
means including a forced fit into the apertures in the tangs or a head at 
one end of the pivot pin, too large to pass through the tang apertures and 
a cotter pin, nut or other suitable attaching means at the other end. 
A pivot arm with a first and a second end and a pivoting means between the 
two ends is secured to the projecting end of the hydraulic rod. In a 
simple version, the projecting end of the hydraulic rod and the first end 
of the pivot arm have aligning holes through which a pivot pin is passed 
and locked into place by means of a cotter pin or other suitable means. In 
a preferred and more stable version, the pivot arm has two legs that 
project from the first end with each leg having an aligning hole through 
it. The end of the hydraulic rod also has a hole in it and the end of the 
hydraulic rod is received between the legs of the pivot arm so that the 
holes in the legs of the pivot arm and the hole in the end of the 
hydraulic rod align so as to receive a pivot pin that is suitably secured. 
The other end of the pivot arm is suitably secured to a control rod of the 
gate valve. This control rod is joined at one end to the gate of the gate 
valve and at the other end to the second end of the pivot arm. The second 
end of the pivot arm is secured to an end of the control rod by means of a 
collar that passes around the control rod and has a projecting tang to 
receive the second end of the pivot arm. The pivot arm and the tang of the 
collar have suitable aligning apertures for receiving a pivot pin through 
them. The pivot pin is secured by means of a locking pin. By removing the 
locking pin and pivot pin, the control rod is capable of being 
disconnected from the hydraulic mechanism of this invention. The collar 
can be secured on the end of the control rod by means of other collars 
that are securely attached to the control rod by means of set screws or 
other locking devices and are positioned on either side of the tanged 
collar. Alternatively, the tanged collar can itself have a set screw for 
locking it to the control rod. 
The invention further consists of a means for securing the pivoting means 
of the pivot arm to the support plate. This is accomplished by providing a 
connecting plate that is attached at one end to the pivot means of the 
pivot arm and at the other end to a tang projecting from the support 
plate. Both ends of the connecting plate are attached to the tang and to 
the pivot arm by means of a pivot pin and suitable fastening means for the 
pivot pin. 
As discussed previously, the hydraulic cylinder is operated by means of 
hydraulic fluid, a method or means for pumping the hydraulic fluid into or 
out of the cylinder or both, such means being a motor, preferably a 
reversing motor, a control means for controlling the motor, hydraulic 
valves in the hydraulic line for controlling the amount of hydraulic fluid 
in the cylinder and as a result, the position of the gate in the gate 
valve, and means for controlling the hydraulic valve such as a solenoid. 
The foregoing and other advantages of the invention will become apparent 
from the following disclosure in which one or more preferred embodiments 
of the invention are described in detail and illustrated in the 
accompanying drawings. It is contemplated that variations in procedures, 
structural features and arrangement of parts may appear to a person 
skilled in the art without departing from the scope of or sacrificing any 
of the advantages of the invention.

In describing the preferred embodiment of the invention which is 
illustrated in the drawings, specific terminology is resorted to for the 
sake of clarity. However, it is not intended that the invention be limited 
to the specific terms so selected and it is to be understood that each 
specific term includes all technical equivalents that operate in a similar 
manner to accomplish a similar purpose. 
Although a preferred embodiment of the invention has been herein described, 
it is understood that various changes and modifications in the illustrated 
and described structure can be affected without departure from the basic 
principles that underlie the invention. Changes and modifications of this 
type are therefore deemed to be circumscribed by the spirit and scope of 
the invention, except as the same may be necessarily modified by the 
appended claims or reasonable equivalence thereof. 
DETAILED DESCRIPTION OF THE INVENTION AND BEST MODE FOR CARRYING OUT THE 
PREFERRED EMBODIMENT 
FIG. 1 is a perspective view showing the general arrangement of the 
components of this invention in a recreational vehicle (RV) 6 shown in 
phantom. It is to be understood that the invention is not limited to RVs 
but, in fact, could be used in any mobile vehicle where it is necessary or 
desirable to have one or more holding tanks and to periodically discharge 
such holding tanks. 
Waste water from toilets (water closets; not shown) is discharged into a 
waste water holding tank 2 while gray water from sinks, showers, and bath 
tubs (not shown) is discharged into a gray water holding tank 4. The 
discharge line 12 from the gray water tank is typically connected to the 
discharge line 8 from the waste water holding tank 2. Discharge line 8 has 
a cap 14 at its end to prevent inadvertent discharge into the environment. 
Manual gate valves 16 and 18 are incorporated into discharge or drain line 
8 and discharge or drain line 12 to control the flow of waste water and 
gray water from the holding tanks 2 and 4, respectively. 
In normal operation, the cap 14 is removed from the end of the discharge 
line 8 and connected to the sanitary sewer by means of a flexible pipe or 
other connecting means(not shown). The waste water holding tank is first 
discharged by opening gate valve 16. After the waste water holding tank 2 
has been discharged, gate valve 16 is closed and the gray water holding 
tank 4 is discharged by opening gate valve 18. The gray water holding tank 
4 is discharged after the waste water in order to rinse the flexible pipe 
or other connecting means. Gate valves 16 and 18 are then closed and the 
end cap 14 replaced on discharge line 8. 
As can be seen in FIG. 1, gate valves 16 and 18 are typically located below 
and toward the center of the RV 6. As such, the operator must kneel or 
otherwise position him or herself under the vehicle to open manually gate 
valves 16 and 18. Such a position is particularly uncomfortable and 
insecure at night and strange surroundings especially when accompanied by 
biting insects and drenching rain. Such a position can be particularly 
unpleasant should the flexible pipe or other means for connecting drainage 
pipe 8 to the sanitary sewer come lose during the discharge of waste water 
from holding tank 2. 
This invention eliminates the need for manual operation of gate valves 16 
and 18 by providing hydraulic mechanisms 20 and 10. These mechanisms are 
essentially similar in nature except for the fact that they are of 
different sizes to accommodate the different sized gate valves found in 
the different sized waste water and gray water lines. The hydraulic 
mechanism is connected to a hydraulic pump, motor, and other control 
devices indicated schematically by the numeral 60 in FIG. 1. The hydraulic 
mechanisms 10 and 20 are connected to the hydraulic center 60 by means of 
hydraulic lines 58 and 56. 
Typically, the switch means 80 is located within the recreational vehicle 6 
while switch means 90 is located on the outside of the recreational 
vehicle 6 in such a position so as to allow the user to observe the 
drainage of the tanks into a sanitary sewer. Switch means 80 has a switch 
82 for controlling hydraulic means 10 and switch 84 for controlling 
hydraulic mechanism 20. Switch means 90 has a switch 92 for controlling 
hydraulic mechanism 10 and switch 94 for controlling hydraulic mechanism 
20. Switch means 80 also has an indicator light 86 to indicate the 
position of gate valve 18 and indicating means 88 for indicating the 
position of gate valve 16. 
By placing hydraulic mechanisms 10 and 20 on gate valves 16 and 18, it is 
possible to discharge the waste water from tanks 2 and 4 either remotely 
from within the recreational vehicle 6 or from a position on the outside 
of the RV 6 so as to observe the discharge from the tanks. Such hydraulic 
mechanisms completely eliminate the need to crawl under the RV to open 
gate valves 16 and 18. 
FIG. 2 is a front elevational view showing the details of the operation of 
the hydraulic mechanism 20. The gate valve (gate valve housing) 16 has a 
circular boss 22 for receiving an end of the discharge line 8. The 
drainage line 8 is joined to the circular boss 22 of the gate valve 16 by 
suitable means such as a plastic cement. The gate valve 16 has a control 
rod 24 that is attached to the gate 21 of the gate valve and projects from 
the gate valve 16 so as to control the movement of the gate by being 
pushed into or pulled out of the gate valve 16. 
In the embodiment shown in FIG. 2, a clamp 26 is passed around the circular 
boss 22. A saddle member 28 is then placed on the U-clamp and the U-clamp 
firmly bolted to the circular boss by means of nuts 30. Two U-clamps are 
used on each side of gate valve 16. A support plate 32 having appropriate 
aligning apertures therethrough to receive the ends of the U-clamp 26 is 
then placed on the ends of the U-clamp 26 and firmly secured to the 
U-clamp by means of nuts 34. 
In an alternate and preferred embodiment shown in FIG. 7, the saddle member 
28 is replaced by a downwardly projecting tang 36 that generally conforms 
to the outer surface of the drainage line 8 or the circular boss 22. In 
FIG. 5, the U-clamp 26 passes directly through the apertures in support 
plate 32 and is bolted thereto. The U-clamp 26 can pass around the 
circular boss 22 or around the drainage pipe 84. For the purposes of this 
description the circular boss 22 is considered to be a part of the gate 
valve 16. 
In another embodiment of the device (not shown), the support plate tang 36 
can have a slot through it capable of receiving a hose clamp. The hose 
clamp is passed through the slot and around the circular boss 22 or the 
drainage pipe 8 so as to secure the support plate 36 to the drainage line 
8 or the circular boss 22 thereby eliminating the U-bolts 26. It is also 
possible to extend the support tang 36 outward (sideways) beyond plate 32 
and pass a clamp or other securing means around the projecting tang 36 and 
the drainage line 8. For the purposes of this invention, these and 
alternate fastening means are considered to be equivalent. 
In yet another embodiment shown in FIGS. 5 and 6, it is possible to secure 
the support plate with one or more downwardly projecting tangs 33,35, and 
37 that are secured directly to the gate valve 16 rather than to the 
circular boss 22 or drainage line 8. The downward projecting tangs 33, 35 
and 37 are fastened to the gate valve 16 by means of suitable fasteners 
such as nuts 31 and bolts 39 passing through the gate valve 16. 
In FIG. 2, the support plate 32 has a hydraulic cylinder tang 38 attached 
to it by means of suitable fasteners such as machine screws 40. The 
hydraulic cylinder 42 is comprised of a cylindrical housing 44, a 
hydraulic rod 46 that projects out of the center of one end of the 
cylindrical housing 44 and a hydraulic cylinder boss (tang) 48 that is 
secured to or a part of the hydraulic cylinder housing 44 at the end 
opposite the hydraulic rod 46. The hydraulic cylinder housing boss 48 has 
an aperture through it and is attached to the hydraulic cylinder tang 38 
by pivoting means such as a pivot pin 50. The pivot pin passes through the 
apertures of the hydraulic cylinder tang and the hydraulic cylinder 
housing tang and is suitably secured by suitable means such as, for 
example, by an enlarged head at one end of the pivot pin 50 and a securing 
pin at the other end of the pivot pin 50. The hydraulic cylinder 42 also 
has a hydraulic line 52 that allows for the admission and release of 
hydraulic fluid into and out of the hydraulic cylinder 42. 
A pivot arm 54 has a first end 56 and a second end 58. The first end 56 is 
secured to the hydraulic rod 46 by means of suitable aligning apertures in 
the hydraulic rod 46 and the end 56 of the pivot arm 54 and a pivoting 
means such as a pivot pin 62. The second end 58 of the pivot arm 50 is 
secured to the control rod 24 of the gate valve 16 by means of a collar 64 
that has a tang 66 having an aperture in it that aligns with an aperture 
in the second end 58 of the pivot arm 54. A pivot pin 68 is passed through 
the apertures in the second end 58 of the pivot arm 54 and the collar tang 
66 and secured b.: suitable means such as an enlarged head at one end of 
the pivot pin 68 and a securing pin such as a cotter or locking pin at the 
other end. The collar 64 may be secured to the control rod 24 by means of 
circular collars 70 and 72. Collar 70 is secured to the control rod 24 by 
means of a set screw 74. As seen in FIG. 3, collar 72 is secured to the 
control rod 24 by means of aligning apertures that pass through both the 
collar 72 and the control rod. A securing pin 76 passes through the 
apertures and secures the collar in place. Using this means of attachment, 
the pin 76 can be readily removed thereby releasing the collar 72 from the 
control rod 24 and allowing the collar 64 to the removed from the control 
rod 24 in those instances where power is lost or the user is otherwise 
unable to control the hydraulic mechanism in its usual fashion. In such an 
instance, a handle 202 (FIG. 7) can be secured to control rod 24 and the 
gate valve 16 manually operated. Alternatively, collars 70 and 72 may both 
be secured to control rod 24 by means of set screws with the second end 58 
of the pivot arm 54 being released from collar tang 66 by removing the 
securing pin (a pin such as pin 76 shown in FIG. 3) from the pivot pin 68 
and removing pivot pin 68. 
Returning to FIG. 2, the pivot arm 54 is secured to the support plate 32 by 
means of a connecting plate 130. The connecting plate 130 is secured to 
the pivot arm 54 by means of aligning apertures in the pivot arm and a 
first end 134 of the connecting plate 130. The apertures are secured with 
a pivot pin 132 and means for securing the pivot pin within the apertures. 
The second end 136 of connecting plate 130 is secured to the support plate 
tang 138 by means of aligning apertures that receive a pivot pin 140 which 
is suitably secured. 
A switch 142 is secured to the gate valve 16 by means of an attaching arm 
144 that is secured to the gate valve 16 by means of a machine screw 146. 
As the pivot arm 54 moves the gate valve rod 24 into the closed position, 
the pivot arm contact flange 148 makes contact with switch 142 causing an 
indicator light 88 to be turned either on or off. Preferably, the light is 
off when the gate 21 is in the closed position and comes on as the pivot 
arm contact flange 148 disengages switch 142 as the gate 21 is opened. 
FIG. 4 illustrates the hydraulic and electrical control system by which the 
hydraulics are operated. Typically, the electrical system operates off of 
the recreational vehicle 6 battery 152. Hydraulic cylinder 170 is operated 
by switch 154 while hydraulic cylinder 180 is operated by switch 172. 
Switches 154 and 172 are three position switches such as a rocker-type 
switch that is disconnected in its center or second position. 
In the first position of switch 154, motor 156 is activated by closing the 
circuit to electrical connector 158. Solenoid 160 is also activated 
through electrical connector 162. Solenoid 160 causes valve 164 to open. 
With valve 164 open, the motor 156 drives pump 166 which causes hydraulic 
fluid to flow from reservoir 168 to the hydraulic cylinder 170 forcing the 
cylinder rod 186 out of the hydraulic cylinder 170. When switch 154 is set 
to its third position, solenoid 160 is activated again opening valve 164. 
Motor 156 is also activated but this time in a reversing mode which causes 
hydraulic fluid to be returned from hydraulic cylinder 170 through the 
pump 166 and into reservoir 168 thereby causing the hydraulic rod 186 to 
be withdrawn into the hydraulic cylinder 170. 
Switch 172 is shown in its second or disconnect position with solenoid 174 
in the closed position. When such switch 172 is moved to its first 
position, solenoid 174 causes valve 176 to open as a result of a 
connection through connector 178. In the first position, motor 156 is 
caused to operate in a forward position, causing pump 166 to pump 
hydraulic fluid from reservoir 168 through valve 176 into hydraulic 
cylinder 180 causing hydraulic cylinder rod 182 to move out of the 
hydraulic cylinder 180. When switch 172 is allowed to return to its open 
position, solenoid 174 closes valve 176 thereby maintaining fluid in 
hydraulic cylinder 180 and the rod 182 in a fixed position. When the 
switch 172 is moved to its third position, the solenoid 174 opens valve 
176 and the motor 156 operates in a reverse manner causing pump 166 to 
withdraw hydraulic fluid from hydraulic cylinder 180 and return it 
reservoir 166 thereby causing hydraulic cylinder rod 182 to be withdrawn 
into the hydraulic cylinder 180 thereby opening gate valve 16. 
The position of the gate 21 in the gate valve 16 can be shown by means of 
indicator lights 188 and 190, each being used with a separate hydraulic 
cylinder. The indicator lights 188 and 190 are used in conjunction with 
contact switches 192 and 194, respectively. As illustrated, the contact 
switch would normally cause the lights 188 and 190 to be in the "on" 
position when the gate valve is open such as is shown in FIG. 2. When the 
pivot-arm contact plate 148 disengages from switch 142 as when the gate is 
in the opened position, switch 142 is closed causing current to flow and 
the indicator light to be activated. 
In FIG. 4, cylinder rods 182 and 186 relate to cylinder rod 46 in FIGS. 2 
and 7, switches 154 and 172 relate to switches 82 and 84 or 92 and 94 in 
FIG. 1, lights 188 and 190 relate to lights 86 and 88 in FIG. 1, and 
switches 192 or 194 relate to switch 142 in FIGS. 2 and 7. 
FIG. 7 illustrates some additional refinements that may be incorporated 
into this invention. Tang 204 rests on the edge of gate valve 16 to 
provide additional stability and ease of assembly when mounting the 
hydraulic mechanism 20 on the drainage line 8 or circular boss 22. Switch 
tang 206 (see also FIGS. 5 and 6) provides a convenient mounting location 
for switch 142. For additional mechanism stability, a clevis can be formed 
at the first end 56 of the pivot arm 54 so that the legs 208 of the clevis 
receive the end of the hydraulic rod 46 between them. Tang 210 can be cast 
as an integral part of support plate 32. In addition, a pair of tangs 210 
can be provided so as to receive the hydraulic cylinder tang 48 between 
them. Tang 212 may also be cast as an integral part of support plate 32. A 
pair of tangs 212 may be used with a pair of connecting plates 130 that 
are placed on each side of pivot arm 54. When a pair of connecting plates 
130 are used, bosses 214 cast as a part of pivot arm 54 (or separate 
sleeves) are used so that a sufficient distance is provided between plates 
130 so that they do not contact switch tang 206 or switch 142. 
It is possible that changes in configurations to other than those shown 
could be used but that which is shown if preferred and typical. Without 
departing from the spirit of this invention, various means of fastening 
the components together may be used. 
It is therefore understood that although the present invention has been 
specifically disclosed with the preferred embodiment and examples, 
modifications to the design concerning sizing and shape may be apparent to 
those skilled in the art and such modifications and variations are 
considered to be within the scope of the invention and the appended 
claims.