Automatic gate valve shut-off device

There is disclosed a system for automatically closing a gate valve of the type customarily installed in a sewer pipe system, the gate valve being positioned such as to divide the pipe into a forward exit section and a rear exit section, the system including fluid sensing means positioned in the forward exit section of the pipe adapted to sense the fluid level, a two phase motor having a forward phase and a reverse phase operationally associated with the gate valve for alternately opening and closing the gate valve, electrical means interconnecting the fluid sensing means and the motor to activate the motor in response to the fluid level sensed by the fluid sensing means, the motor including switch activation means associated therewith and mounted for arcuate movement about a pivot point, and switch means for alternately controlling the forward and reverse phases of the motor, the switch means being mounted in position within the arcuate path of travel of the switch activation means.

BACKGROUND OF THE INVENTION 
The present invention relates to a system for automatically opening and 
closing a gate valve of the type commonly used in connection with sewer 
systems as applied to either a residential or commercial building 
installations. As is well known, gate valves are traditionally installed 
for the purpose of preventing backflow of sewer water or other undesired 
fluid forced back through a pipe due to extreme back pressure. In the 
typical installation, such gate valves are manually operable by means of a 
circular wheel which is rotated by the user in order to close the valve 
thereby occluding the sewer pipe in situations where it is anticipated 
that a back pressure is being created which may possibly cause a back 
pressure flow of the undesired fluid. 
For example, in home installations, gate valves are typically installed 
adjacent to the sump pumps such that when a situation arises where the 
sump pump can no longer handle the tremendous rise of the water level from 
rain water or the like, and it is evident that a back pressure situation 
is being created in the municipal sewer system, the gate valve may be 
closed thereby to occlude the sewer pipe and prevent the municipal sewer 
water from being forced back into the home due to the extreme water 
pressure being created. However, it is evident that in order to operate 
the gate valve, the homeowner must be present, and must manually 
reciprocate the gate valve in order to effect a closing off of the sewer 
pipe. In addition, in many instances, the homeowner may not even be alert 
to the fact that a back pressure situation may exist, and hence, sewer 
water may be backing into the system and into the home, without the 
homeowner having a sufficient warning in order to actually manipulate the 
gate valve and close the house off from the municipal system. 
In order to overcome some situations relating to the lack of awareness of 
the homeowner, various systems have been developed in the nature of alarm 
systems which would alert the homeowner to a back pressure situation. 
Various prior patents deal with alarm systems created for such situations 
set for the purpose of alerting and warning the occupant of the need to 
close the gate valve. For example, U.S. Pat. No. 2,773,251 discloses a 
back flow prevention and alarm device, which in reality, is simply an 
alarm system for indicating leakage in a check valve or for the presence 
of back flow conditions. It is disclosed therein, the device depicted in 
the subject patent takes advantage of a pressure differential existing as 
between the valve chamber and the pressure in the supply line, which come 
under normal conditions, will not activate the contacts, but under a back 
flow situation, will activate the contacts to the alarm bell thereby to 
alert the occupant to a back flow situation, or at least the leakage of 
the valve. Under extreme conditions, the alarm is sounded in order to 
alert the operator to take such measures as may be necessary to prevent 
back flow from occurring. 
Similarly, U.S. Pat. No. 4,398,186 is again directed to a sewer back up 
warning system which utilized an electrically conductive float which rises 
under conditions of back flow thereby to activate a rod which in turn 
completes an electrical circuit containing the back up alarm. It is 
evident that with respect to the two patents discussed herein, both 
disclose only an alarm system, which when activated, still requires that 
the operator manually close the gate valve in response to a back flow 
situation. 
Other prior art patents have similarly attempted to devise systems for 
relieving the back flow pressure, such as that disclosed in U.S. Pat. No. 
4,392,128. The device disclosed therein incorporates a blow-off cap 
including an alarm which is set off by the rising fluid immersing to 
contacts. As is disclosed therein, a buzzer is set off due to the rising 
water level, after which a blow-off cap may be exploded due to the water 
pressure in order to relieve the back flow pressure, although the back 
flow of fluid is certainly not prevented. Hence, it is still incumbent 
upon the oocupant to take such steps as may be necessary in order to 
manipulate a gate valve in order to close off the sewer pipe and stop the 
undesired back flow of fluid. 
In terms of a system designed to actually shut off the back flow of fluid 
in a back flow situation, U.S. Pat. No. 4,432,388 discloses an automatic 
system for preventing the back up of sewage in a gravity discharge line. 
As disclosed therein, the device consists of an expandable bladder 
consisting of a folded or a pleated bladder which will expand when a 
reverse flow of the fluid is present. Hence, while the device disclosed 
therein does not operate a gate valve in order to shut off the sewer line, 
the device is intended for insertion into the sewer pipe line, and when a 
reverse flow of the fluid is realized, the bladder will expand until the 
opening in the sewer pipe is occluded. Legably, when the back flow 
situation subsides, the fluid would be expunged from the bladder such that 
the pleats or folds in the bladder reappear, thereby to open the fluid 
flow path in the proper direction. 
Attempt to create an automatic system for occluding the sewer pipe is 
disclosed in U.S. Pat. No. 2,630,875. As shown therein, the invention 
consists in providing a back water valve which may be associated with a 
drain pipe, or the like, and may be manually operated, or automatically 
operated by means responsive to the rising or backing up of water in the 
sewer pipe or floor drain. When that does occur, the valve, upon the rise 
of the water, will immediately be closed and remain in such position until 
the liquid recedes, after which the valve will again be brought to the 
open position. Hence, in order for a system of the type disclosed in U.S. 
Pat. No. 2,630,875 to be operable, an additional valve must be positioned 
in the sewer line in order to operate properly. 
What is significant is that the prior art has not yet been able to provide 
a system which may be retrofitted to an existing gate valve, and which 
will operate to automatically open and close the gate valve in response to 
a back pressure situation such as created by heavy rains, flooding or the 
like. The present invention is intended to provide a system which will 
automatically operate an existing gate valve, and which may be retrofitted 
to the same, such that the gate valve will be opened and closed in 
response to the rising and falling of the fluid in the sewer pipe, 
automatically, without the need of providing additional valves or the 
like. 
OBJECTS AND ADVANTAGES 
It is therefore the prinicpal object of the present invention to provide a 
system which may be retrofitted to any existing gate valve, which will 
operate to automatically open and close such gate valve in response to the 
rising or falling of the fluid level in the pipe. 
In connection with the foregoing object, it is a further object of the 
invention to provide a system for automatically activating a gate valve of 
the type positioned in the fluid flow path of a pipe such as to divide the 
pipe into a forward exit section and a rear exit section, the system 
including fluid sensing means positioned in the forward exit section of 
the pipe adapted to sense the fluid level of the pipe, a two phase motor 
having a forward phase and a reverse phase operationally associated with 
the gate valve for alternately opening and closing the gate valve, 
electrical means interconnecting the fluid sensing means in the motor in 
order to activate the motor in response to the fluid levels sensed by the 
fluid sensing means, the motor including switch activation means 
associated therewith and being mounted for arcuate movement about a pivot 
point, and switch means for alternately controlling the forward and 
reverse phases of the motor, the switch means being mounted and positioned 
in the arcuate path of travel of the switch activation means, whereby a 
rise of the fluid level within the pipe will be sensed by the fluid 
sensing means and automatically electrically activate the motor to turn 
the gate valve into the closed position in order to occlude the fluid path 
and seal the forward exit section of the pipe from the rear exit section 
thereof, while the continued operation of the motor causes the motor and 
the associated switch activation means to move arcuately about the pivot 
point and move the switch means to simultaneously deactivate the motor and 
change the phase of the motor from the forward phase to the reverse phase, 
while a lowering of the fluid level in the pipe will similarly be sensed, 
and the reverse of each of the operational steps will be achieved in order 
to open the fluid flow path and reset the motor phase to the forward 
phase. 
In connection with the foregoing object, it is a further object of the 
invention to provide a system for automatically operating a gate valve of 
the type described, wherein the motor and the switch activation means are 
fixedly interconnected and carried on a holding plate such that the motor 
as well as the switch activation means will rotate about a pivot point 
thereby to move the switch activation means throughout an arcuate path of 
travel, with the switch means controlling the forward and reverse phases 
of the motor being located such that the switch activation means will 
strike the switch means as the motor and switch activation means rotate 
throughout the arcuate path of travel. 
In conjunction with the foregoing object, it is a further object of the 
invention to provide a system of the type described wherein the system is 
provided with a mounting standard for fixed securement to an underlying 
support surface in juxtaposition with respect to an existing gate valve, 
such that said system may be retrofitted to an existing gate valve without 
requiring any additional valves or other accoutrements to be added to the 
existing sewer system. 
In conjunction with the foregoing object, it is a further object of the 
invention to provide a system for automatically opening and closing a gate 
valve, of the type described, wherein the motor and switch activation 
means and switch means are mounted on a bar which may, in turn, be 
adjusted such that said system may be easily applied to an existing gate 
valve with adjustments being capable in order to accurately and properly 
amount the system both vertically and horizontally with respect to the 
existing gate valve. 
Further features of the invention pertain to the particular arrangement of 
the parts whereby the above-outlined and additional operating features 
thereof are attained. 
The invention, both as to its organization and method of operation, 
together with further objects and advantages thereof will best be 
understood by reference to the following specification taken in 
conjunction with the accompanying drawings.

BRIEF SUMMARY OF THE INVENTION 
In summary, the present invention is directed to a system which may be 
retrofitted to an existing gate valve of the type positioned in a sewer 
system for alternately opening and closing the fluid path traversing the 
sewer pipe, the system being designed to be affixed to the existing gate 
valve, and includes fluid sensing means positioned in the forward section 
of the sewer pipe adapted to sense the fluid level within the pipe, a two 
phase motor having a forward phase and a reverse phase operationally 
associated with the gate valve for alternately opening and closing the 
gate valve and therefore opening and closing the fluid path traversing the 
pipe, electrical means interconnecting the fluid sensing means from the 
motor thereby to activate the motor in response to the fluid level as 
sensed by the fluid sensing means, the motor including switch activation 
means associated therewith and mounted for arcuate movement about a pivot 
point, and switch means for alternately controlling the forward and 
reverse phases of the motor, the switch means being mounted and positioned 
for activation by the switch activation means as the same traverses an 
arcuate path of travel. 
DETAILED DESCRIPTION OF DRAWINGS 
The overall system of the present invention is depicted in FIG. 1 of the 
drawings, and represents the automatic system for alternately opening and 
closing the gate valve. The system 10 is shown to include fluid sensing 
means 12 which is formed by fluid probe 13, which is interconnected by a 
pair of electrical contacts 14 and 16 respectively, to a relay 18. The 
relay 18 is in turn connected to an on/off switch 19 for supplying 
electrical power to the system and to a reversing switch 45 which controls 
the operation of the motor 50. 
As shown in FIG. 1 of the drawings, the sewer pipe 23 as shown to be 
positioned in subflooring 24 and includes a gate valve assembly 25 which 
is a typical installation as may be found in residential as well as 
commercial installations. As depicted in phantom in FIG. 1, a typical gate 
valve assembly 25 usually includes a manual wheel 26 which operates the 
valve block 28 within the valve housing 29. The valve housing 29 in 
effect, divides the sewer pipe 23 into a forward exit section 31, and a 
rear exit section 33 as shown in FIG. 1. In the typical sewer 
installation, the fluid flow path is in the direction of the arrow D 
thereby to exit from the building installation, and enter into the 
municipal sewer system as is well known in the art. 
As indicated previously, the automatic gate valve closure system of the 
present invention is shown to include a motor 50, which is secured to a 
mounting plate 35 by means of lug bolts 36 and 37 respectively. The 
mounting plate 35 further includes switch activation means 38 which is 
basically formed by a U shaped plate 39 welded to, or otherwise formed 
integrally with the mounting plate 35. It will be observed that the U 
shaped plate 39 includes an open section depicted by the numeral 41 which 
accommodates therebetween a switch box 43 as indicated in FIGS. 1, 4 and 
5. Switch box 43 is shown to include a two position switch 45 which is 
reciprocated between the two positions by means of a wire pull 47 coupled 
to its toggle 46. The wire pull 47 is interconnected to the U shaped plate 
39 by means of a pair of holding legs 48 and to the switch 45 by switch 
loop 49. 
The entire system is shown to be carried by a standard 52 which, is in 
turn, slideable carried on a mounting rod 54 which is formed integrally 
with a support plate 55 which may, in turn, be bolted to the underlying 
flooring F by lug bolts 56 and held in position by wing nut 57. The 
precise manner of mounting the support plate to the underlying flooring 55 
is not deemed to be critical to the inventive subject matter herein, since 
any manner of securely fastening the support plate 55 to the flooring may 
be utilized. It will also be apparent that the standard 52 may include any 
typical type of lock mechanism (not shown) for locking the standard 52 in 
any desired position along the mounting rod 54. For example, a threaded 
holding bolt may be employed if desired, or in the alternative, a threaded 
aperture may be applied through collar 53 through which a threaded bolt 
may be applied in order to securely lock the standard 52 in any desired 
position along the mounting rod 54. 
The standard 52 further includes a horizontal sleeve 59 which accommodates 
a slideably moveable support rod 61 therein. The support rod 61 is shown 
to support the switch box 43 containing the two position switch 45 
therein, as well as to support the U shaped plate 39 carrying the motor 50 
thereon. The combined U shaped plate 39 and the motor 50 are shown to be 
pivotally mounted to the support rod 61 by means of a bolt 63 positioned 
through appropriate apertures through the U shaped plate 39 in order to 
securely set the bolt 63 in position. As will be observed in FIGS. 1, 4 
and 5 of the drawings, the open section 41 of the U shaped plate 39 is 
sized such that it will clearly accommodate therebetween the switch box 43 
as well as the dimensional sizing of the support rod 61. As indicated, the 
entire assembly including the U shaped plate 39 as well as the motor 50 is 
designed to pivot about the bolt 63 in a manner which would be indicated 
hereinafter. 
The underside of the support rod 61 is shown to include an L shaped bracket 
65 which has one leg thereof secured to the support rod 61, and has the 
opposed leg thereof extending downwardly from the underside of the support 
rod 61. Similarly, the outer surface of the lower portion of the U shaped 
plate 39 includes an L shaped bracket 67 which again includes one leg 
thereof secured to the U shaped plate 39, and the opposed leg extending 
downwardly therefrom. As shown in FIGS. 1 and 2 of the drawings, a 
compression spring 69 is fixedly secured between the two vertically 
extending legs of the respective L shaped bracket 65 and 67 respectively. 
The motor is shown to further include a square motor shaft 70 which is 
operated by the motor 50, surrounded by a shaft rod 71 which has a square 
shaped internal bore being sized to accommodate the square motor shaft 70. 
As is well known in the art, the manual wheel 26 found mounted to the 
typical gate valve 25 is generally provided with a square shaped bore in 
order to accommodate the square shaft leading from the valve block 28. In 
the typical gate valve 25, the valve block 28 is reciprocated between the 
open and close position by means of a threaded shaft 73 the upper end of 
which is square shaped as depicted in FIG. 3. Hence, when the manual valve 
wheel 26 is turned, the threaded shaft 73 is similarly turned thereby to 
screw threadedly reciprocate the valve block 28 into position or out of 
position. The present invention contemplates substituting the manual valve 
wheel 26 by simply utilizing the shaft rod 71 which, as indicated, 
includes a square shaped bore 72 thereby to accommodate the positioning 
therein of the threaded shaft 73. Hence, once the motor shaft 70 commences 
turning, it will in turn turn the shaft rod 71, which in turn rotates the 
threaded shaft 73 in order to move the valve block 28 into and out of the 
occluding position. 
Operationally, the switch 19 is operated between an on and an off position 
to supply and cut-off electrical power to the system, while the two 
position switch 45 is operated to control the forward and reverse phases 
of the motor 50. It will therefore be appreciated the present invention 
contemplates that the motor 50 be a two phase motor having both a forward 
and a reverse phase associated therewith. 
In operation, the switch 19 is operated to its on position. Initially, the 
switch 45 has been operated such that its contacts 76 and 77 are closed. 
Also, the relay contact 75 is closed. With specific reference to FIG. 1 of 
the drawings, in a normal situation, sewer water traverses the sewer pipe 
23 in the direction of the arrow D and exists the subject building via the 
rear exit section 33, through the forward exit section 31, and into the 
municipal sewer. In those situations where excessive rain water or flood 
conditions occur, back pressure occurs, thereby forcing water back through 
the forward exit section 31 in the reverse direction of arrow D. It will 
be appreciated that as the back pressure of the water increases, water 
will be forced into the upstanding pipes 15 wherein the probe 13 is 
located. The probe 13 is designed to sense the presence of fluid, and 
close a circuit (not shown), which then sends an electrical signal via 
electrical contacts 14 and 16 respectively to relay 18. The relay then 
operates and, as illustrated in FIG. 6, closes the contact 74 to couple 
power through contacts 76 and 77 of the switch 45 to the motor 50. The 
motor 50 is activated and the motor shaft 70 is caused to turn, which in 
turn, causes a circular movement of the shaft rod 71. The concommitment 
rotational force is therefore applied to the threaded shaft 73 which 
commences the movement of the valve block 28 into an occluding position 
relative to the sewer pipe 23. It will also be appreciated that once the 
valve block 28 has been set into position within the valve housing 29, the 
motor 50, which is continuing to operate, and will continue to tend to 
rotate the motor shaft 70 will meet resistance since the valve block 28 
has now bottomed. The torque associated with the motor 50 will now 
overcome the tension of the compression spring 69, and cause the U shaped 
plate 39 and motor 50 to pivot about the pivot pin 63. As the U shaped 
plate 39 pivots, the wire pull 47 will pull the toggle 46 of the two 
position switch to open the contacts 76 ad 77 and to close the contacts 78 
and 79. As can be seen in FIG. 6, opening the contacts 76 and 77 shuts off 
the motor 50 since the relay contact 75 is open, thus there is no power 
coupled to the motor 50. Also, the reverse position motor is set by the 
switch 45 in its reverse phase position. The indicator light 80, at this 
time, is energized, to provide a visual indication that the valve block 28 
is closed. As shown in FIG. 2, the pivotal movement of the U shaped plate 
39 to the reverse phase position of the motor is shown in phantom. It will 
also be appreciated that once the water level in the pipe 23 subsides, the 
fluid probe 13 will again sense the lack of fluid, and will again send 
that information via electrical contacts 14 and 16 to the relay 18 to 
close contact 75, which will again activate the motor 50. At this time, 
once the motor is activated, since the motor 50 has been set in the 
reverse phase, the motor shaft 70 will turn in the reverse direction, 
which therefore reverses the movement of threaded shaft 73 thereby moving 
the valve block 28 to the upper or open position relative to sewer pipe 
23. As the valve block 28 is moved to its highest position, and as the 
motor 50 continues to operate, the torque of the motor will overcome the 
tension, once again, of compression spring 29 and cause the U shaped plate 
39 as well as the motor 50 to once again pivot about the pivot pin 63 
thereby arcuately moving back to its original position as shown in solid 
lines in FIG. 2. This movement of the U shaped plate 39 will cause the 
wire pull 47 to once again pull the toggle 46 of the switch 45 to the 
opposed position thereby again opening the contacts 78 and 79 to turn off 
the power to the motor 50, and to set the motor in the forward phase 
thereof, simultaneously. The motor 50 is therefore set, when activated 
once again, to commence movement of the motor shaft 70 in the forward 
phase which will have the effect of again, turning the threaded shaft 73 
in the forward phase thereby moving the valve block 28 back into an 
occluding position within the valve housing 29 to occlude pipe 23. The 
indicator light 80 also is de-energized, indicating that the valve block 
28 is open. 
It will also be appreciated from the manner in which the standard 52 is 
constructed, the collar 53 is movable along the vertical length of the 
mounting rod 54 such that the entire assembly may be adjusted in a 
vertical direction to any desired height depending upon the positioning of 
the gate valve 25 which may be located any given installation. It will 
also be appreciated that the switch box 43 containing the switch 45, as 
well as the U shaped 39 and the motor 50 are mounted on the support rod 61 
which is telescopically movable within the horizontal sleeve 59 forming a 
part of the standard 52. Hence, once the support plate 55 is securely 
bolted in position on a given flooring F, the entire assembly may be 
adjusted and moved into proper position such that the motor shaft 70 is in 
direct lineal alignment with the threaded shaft 73 of the gate valve 25. 
It will also be appreciated that the entire assembly which is connected to 
the support rod 61 and the standard 52 may be removed form the mounting 
rod 54 by simply disconnecting the locking means holding the collar 53 to 
the mounting rod 54 such that the assembly may be entirely removed. This 
facilitates the cleaning of the gate valve 25 when desired. Hence, the 
only permanent installations which are necessitated by the system of the 
present invention consists of the insertion of the upstanding pipe 15 to 
interconnect with the sewer pipe 23, and the fluid sensing means 12 which 
is contained within the upstanding pipe 15, and the permanent mounting of 
the relay 18 and motor switch 19. Of course, the support plate 55 is 
bolted in position, but the entire remaining assembly is, as indicated in 
FIG. 1 of the drawings, entirely carried by the support rod 61 such that 
the entire assembly may be easily removed. 
It will also be appreciated that while the present invention is shown to be 
provided with a U shaped plate 39 as described, which functions to not 
only carry the wire pull for reciprocating the two phase switch to the two 
positions, but also carries the compression spring for setting the tension 
point at which the entire assembly will pivot about the pivot bolt 63, any 
mechanical equivalent can be employed in order to function in the manner 
indicated for the U shaped plate 39. Hence, any mechanical equivalent may 
be employed so long as the same operates to activate switch 45 as well as 
to employ tension means which must be overcome once the motor has caused 
the valve block to bottom out thereby to force the motor to pivot on a 
pivot point. 
It will be appreciated that there has been provided by virtue of this 
invention, an improved, but yet simplified, automatic system for opening 
and closing an existing gate valve of the type generally operated by 
manual means, in any number of installations. The present system 
incorporates various components which are basically standard items, and 
therefore, the economic cost of constructing a system of the type 
described is minimal. On the other hand, the present system is efficient 
in that it operates automatically to either open or close the gate valve 
in response to the level of fluid in the sewer pipe, without the need of 
an operator to manually open or close the gate valve. It will also be 
appreciated that while the invention has been described with respect to 
obtaining power from an existing DC source, a battery pack may be provided 
such that the system could be operated out of a 12 volt battery system 
such that in the event that a main power outage were experienced, the 
automatic gate valve system of the present invention would operate. 
However, it is not deemed to be part of this invention since it is obvious 
that any number of electrical systems may be operated off of a battery 
pack or a generator system apart from a direct electrical system as may be 
found in any existing building structure, but it is deemed advantageous to 
indicate that the subject system may in fact be operated off of a battery 
system or a generator system apart from the existing electrical system. 
While there has been described what is at present considered to be the 
preferred embodiments of the invention, it will be understood that various 
modifications may be made therein and it is intended to cover the appended 
claims all such modifications as followed in the true spirit and scope of 
the invention.