US3253790A

US3253790A - Safety control

Info

Publication number: US3253790A
Application number: US414501A
Authority: US
Inventors: Willard F Foster
Original assignee: C H HEIST OHIO CORP
Current assignee: C H HEIST OHIO CORP
Priority date: 1964-11-19
Filing date: 1964-11-19
Publication date: 1966-05-31
Anticipated expiration: 1983-05-31

Description

May 31, 1966 w. F. FOSTER 3,253,790

SAFETY CONTROL Filed Nov. 19, 1964 5 Sheets-Sheet l INVENTOR. 'ZUZYZQFJF f ATTOPNEY.

May 31, 1966 w. F. FOSTER 3,253,790

SAFETY CONTROL Filed Nov. 19, 1964 5 SheetsSheet 2 INVENTOR.

ATTORMY.

United States Patent York Filed Nov. 19, 1964, Ser. No. 414,501. 12 Claims. (Cl. 239-569) The present invention relates to an improved safety control and more particularly to a pneumatic dead mans control for use with high pressure jet apparatus which is utilized for removing incrustations from industrial tanks and the like. The present application is a continuation in-part of application Serial No. 325,734, filed November 22, 1963, now abandoned.

in the preferred method of cleaning of incrustations or other deposits from industrial tanks and the like, a jet of liquid at a pressure of between 3,000 and 4,000 p.s.i. is directed at the incrustations to remove them. The jet emanates from a lance which is held by an operator. The jet has sufiicient force so that it can penetrate the human body. Furthermore, in the event that this I jet should strike inanimate objects it may tear them apart with subsequent economic loss. Generally the only times that the foregoing undesired occurrences may be experienced is when the lance operator loses control of the lance, as when he falls, or upon the starting up of the apparatus, that is, when a valve is opened to permit the high pressure liquid to pass through the lance so that the jet of liquid emanating therefrom cause-s the lance to react against the operators hold thereon. In addition, in the past, when a plurality of lances were operated from a single source of hydraulic fluid, any change in operating characteristics of one lance had an effect on the other lances, so that a lance operator would experience wide variations in the pressure of the hydraulic fluid emanating from his lance. It is with the providing of an improved pneumatic dead mans switch which automatically overcomes the foregoing problems that the present invention is concerned.

It is accordingly one object of the present invention to provide an improved pneumatic control which not only automatically causes the gradual build-up of the pressure of liquid which is projected from a lance to thereby permit an operator to have full control of the lance' while the pressure is building up but which also automatically causes the lance to stop discharging high pressure liquid substantially instantaneously in the event that the operator should for any reason lose control of the lance, to thereby prevent injury to persons or property in the event that the lance is inadvertently directed toward them.

Another object of the present invention is to provide an improved pneumatic circuit having a plurality of hydraulic lances controlled thereby and operated from a single source of hydraulic fluid so that the lances and their associated pneumatic and hydraulic circuits operate in such a manner so as to not only achieve the foregoing object but also permit the operation of any of the lances to be terminated for any reason whatsoever without aflfecting the hydraulic pressure supplied to any of the remaining lances which are in operation.

Another object of the present invention is to provide an improved pneumatic control which requires the operator to exert only a relatively small force on the control, the pneumatic circuitry being inherently capable of providing magnified forces for actuation of the components thereof in response to said relatively small force.

Yet another object of the present invention is to provide a pneumatic-hydraulic system associated with jet cleaning apparatus wherein there can be changes in flow conditions without hydraulic and pneumatic shock thereby making it easier for personnel to man the apparatus and also reducing the wear on the apparatus and therefore prolonging its useful life.

A further object of the present invention is to provide an improved fluid pressure operated dead mans control in combination with apparatus for projecting high pressure liquid against incrustations in industrial tanks or the like which may contain combustible gases to thereby obviate the possibility of explosions which could occur as a result of the ignition of such gases by arcing if electrical controls were used.

Still another object of the present invention is to provide an improved pneumatic dead mans switch for a lance which directs high pressure liquid against incrustations, with only a small portion of the control .being carried by the lance and the remainder of the control and the various valving for terminating flow of high pressure liquid being located at a position remote from the lance, so that the lance operator is not burdened by the weight of either the control or the liquid valving. Other objects and attendant advantages of the present invention will readily be perceived hereafter.

The improved pneumatic dead mans control of the present invention is capable of causing pressure of hydraulic fluid to be built up gradually in a lance which directs a jet of this fluid at incrustations in industrial tanks, thereby obviating the possibility that the lance will be thrown from an operators hands, as would be the case if this pressure were built up abruptly. The gradual build up of pressure minimizes shock in the system and therefore also prolongs the life of the components thereof. The foregoing gradual build up of pressure is attained by the operators manipulating of a grip type of valve and holding this valve in an on position. The pneumatic circuitry associated with this valve and with the various other controls of the system permit a minimum of force to be utilized by the operator in holding the valve in a position which will permit the jet to be supplied from the lance. Furthermore, most of the components of the pneumatic control are located at a position which is remote from the lance thereby obviating the necessity for the lance operator to bear the weight of said components, with attendant fatigue. However, in the event that the operator should lose control of the lance, as would be the case in the event that he stumbled or if he lance was knocked from his hands, he would lose his grip on the above-mentioned grip valve and it would automatically return to a position wherein it would instantaneously stop the flow of the jet from the lance. Therefore in the event that the lance was directed at a person or at fragile property after the operator lost control, there would be no injury. It is to be especially noted that when flow of the hydraulic fluid from the jet is stopped abruptly, there is no hydraulic or pneumatic shock in the system because of the manner in which it is constructed. This obviating of shock also prolongs the life of the apparatus. Both the initiation of flow through the lance in a gradual manner and the termination of flow through the lance in an abrupt manner are both achieved automatically by the operators manipulation of the above-noted valve. Since the control arrangement for achieving the foregoing results is fluid pressure operated, the instant apparatus can be safely used in industrial environments which contain combustible gases without fear of explosions which might otherwise occur if the control apparatus contained electrical components which could produce arcing.

Furthermore, in accordance with the present invention a system is provided wherein a plurality of pneumatic controls are all operated from a common compressed air source and a plurality of lances are all operated from a common source of hydraulic pressure, and the initiation or termination of operation of any of the lances will in no way affect the operation of the others or in any way cause any reaction at either the compressed air source or the source of hydraulic pressure which is detrimental to the operation of the system. The manner in which the foregoing results are achieved and the apparatus which is utilized will be more fully understood when the following portions of the specification are read in conjunction with the accompanying drawings wherein:

FIG. 1 is'a plan view of the improved dead mans switch of the present invention;

'FIG. 2 is an elevational view of the structure of FIG. 1;

FIG. 3 is a view of the lance which is utilized to project high pressure water against incrustations and is shown mounting the dead mans control switch;

FIG. 4 discloses a foot switch which may be used instead of the hand switch of FIG. 3;

FIG. 5 is a schematic view of the improved pneumatic dead mans control of the present invention;

FIG. 6 is a schematic view of an improved system employing a plurality of lances each actuated from a separate control which permits this lance to be started up or shut off without aflecting the operation of any of the other lances of the system; and

FIG. 7 is an enlarged detail view of a portion of FIG. 6.

The improved dead mans switch of the present inven* tion is preferably located in a locked container 10 (FIGS. 1 and 2) to prevent anyone from tampering with it after it has been set up for proper operation. The structure in box 10 is for the purpose of selectively routing high pressure water or other liquid to lance 11 (FIG. 3) which is essentially a hollow tube with a nozzle 12 at the end thereof. Lance 11 has the end thereof which is remote from nozzle 12 connected to flexible conduit 13 (FIG. 5) which is in turn connected to conduit I14 leading from box l10. Conduit 14 conducts high pressure water or other solvent at a pressure of between 3,000 and 4,000 p.s.i. to lance to 1 1. As noted above, an operator holds lance 11 and directs the jet of liquid emanating from nozzle 12 at incrustations which form a lining of industrial tanks, pipes, or the like.

Whenever it is desired to initiate flow of liquid through lance 11, it is merely necessary for the operator who is holding lance 11 to put his hand around both lance 11 and lever 15 (FIGS. 3 and 5) of manual switch or grip valve 16 and cause lever 15 to pivot about pin 17 from the position shown in FIG. 5 to the position shown in FIG. 3, pin '17 being mounted on valve body 21 which is in turn secured to lance 11 by strap 19 which encircles projection 18 extending from valve body 21 and said lance. The movement of lever 15 to the position shown in FIG. 3 is against the bias of leaf spring 20 which is mounted on body 21 of valve 16. When lever 15 is in the position shown in FIG. 3, valve element 21' covers aperture 22 at the end of conduit 23 which leads through valve body 21 and is in communication with compressed air conduit 24. I

It is to be noted from FIG. 5 that a source of compressed air 25 is provided and this source is in communication with conduit 24 leading to valve 16 through conduit 26, union 27, conduit 28, air filter 29, conduit pressure regulating and reducing valve 31, conduit 32, conduit '33, pressure reducing and regulating valve 34, conduit 35, orifice union 36, conduit 37 and chamber 38 of pressure responsive control valve 39. Pressure reducing valve 34 serves the function of causing the pressure which is supplied to valve 39 to be of proper value for operation of said valve. Furthermore, for all purposes of adjusting valve 34 a gauge 40 may be inserted in conduit and pressure reducing valve 34 may be suitably adjusted by the manipulation of screw 41 as is well known in the art.

Orifice union 36 is, as the name implies, a union which has an orifice plate therein for causing a pressure drop when there is. a flow o'f fluid through the union but permitting the static pressure to be equalized on both sides of the orifice plate when there is no flow. The abovementioned pressure reducing and regulating valve 31 serves the function of reducing the pressure in line 28, which may be of a magnitude of p.s.i., to a value of 60' p.s.i. in line 33. A meter 67 is provided in conduit 46 tov aid in the adjustment of pressure reducing valve 31 by means of the manipulation of handle 31 as is well known in the art. As will become more apparent hereafter, this 60 p.s.i. pressure is that which is required for the operation of fluid pressure motor 49. Furthermore, pressure reducing and regulating valve 34 further reduces the 60 p.s.i. pressure in line 33 to a pressure of 6 p.s.i. in line 35. The reason for reducing the pressure in the foregoing manner to 6 p.s.i. is so that this pressure will exist at valve 16 and therefore a very small amount of force will be required on the part of the operator to hold lever 15 of valve 16 in the position shown in FIG. 3. In other words, if a very high pressure existed in conduit 24, a large amount of force would be required to hold lever 15 in the position shown in FIG. 3. Because only a small amount of force is required, the operators hand will not become tired.

Whenever valve 16 is closed in the above-described manner by causing valve element 21' to cover aperture 22 by holding lever 15 in the position shown in FIG. 3 against the bias of spring 20, the pressure in conduit 24 will build up and therefore cause flexible diaphragm 41 in valve 39 to move downwardly (FIG. 5) against the bias of spring 42 and carry valve stem. 43, which is attached thereto, with it tothereby cause valve portion 44 of valve 39 to move from an open position wherein it permits communication between

conduits

45 and 46 to a position wherein it terminates said communication. When valve portion 44 closes, the compressed air in conduit 32 leading from compressed air source 25 will build up the pressure in conduits 46 and 47' leading to conduit 48 which is in communication with chamber 49 of fluid pressure motor 49. As the pressure in conduits 47 and 48 build up, the piston 50 in fluid pressure motor 49 will be caused to gradually move from its dotted line position to its solid line position against the bias of spring 51 and therefore cause piston shaft 52 to move valve element 53 which is coupled to piston shaft 52 by valve lever 54 to the position shown in FIG. 5 from a position wherein it permitted communication between

conduits

56 and 57 through conduit 159.

It is to be noted that the movement of piston 50 from its dotted line position to its solid line position occurs slowly and therefore the movement of valve element 53 of valve 55 to its position shown in FIG. 5 also occurs slowly and therefore causes the pressure of water in conduit 56 to build up gradually thereby giving the lance operator good control of the lance as the jet of fluid emanating therefrom builds up in pressure. In other words there will be no instantaneous discharge of a jet of high pressure liquid from nozzle 12 which could cause the lance 11 to be thrown out of the operators hands as a result of the reaction produced by the jet. More specifically, it is to be noted from FIG. 5 that a source of water or other cleaning fluid 58' is provided and a pump 59 causes this fluid to travel into conduit 60 which is in turn in communication with conduit 61 leading to Y 62. One branch of Y 62 leads to conduit 63 which in turn is in communication with conduit 14 leading to lance 11. The other branch of Y 62 leads to conduit 56 which is in communication with valve 55. It can thus be seen that as valve element 53 of valve 55 closes in the above-described manner, more liquid will be caused to flow to lance 11 and the pressure of this liquid will be built up gradually in lance 11 because less and less of it is diverted from lance 11 through conduit 56.

As long as the operator maintains grip valve 16 closed, that is, in the position shown in FIG. 3, a high pressure jet of liquid will be projected from nozzle 12 of lance 11. However, if for any reason the operator should lose control of the lance, that is, in the event he falls while moving the lance along the wall of a chemical tank or the like, or if it should be knocked from his hand as he is moving it, lever 15 of valve 16 will immediately be caused to pivot in a counterclockwise direction in FIG. 3 from the position shown in FIG. 3 to the position shown in FIG. 5 by spring 20 to thereby cause valve element 21 to be unseated from aperture 22. Immediately upon the unseating of valve 21 there will be a loss of pressure in conduit 24 leading to valve 16 and in turn there will be an immediate loss in pressure in chamber 38 of valve 39. This loss in pressure in chamber 38 will be accompanied by the expansion of spring 42 to thereby move diaphragm 41 upwardly and therefore cause valve shaft 43 to cause valve 44 to open immediately. When valve 44 opens, the pressure in

conduits

45 and 48 leading to fluid pres- 'sure motor chamber 49' will immediately be dissipated because valve 44 will permit communication between .

tween conduits

45 and 46 is closed, there can be a build vmotor 49. However, the flow ofcompressed air from conduit 46' into conduit 47' will still continue, but since there is a metering orifice 66 in orifice union 65, there will be a suflicient pressure drop so that when valve 44 is open to permit communication between

conduits

45 and 46, the pressure in conduit 47 which is in effect the same conduit 45 and conduit 46 leading to vent 58. As soon as chamber 49 of motor 49 is vented, the air pressure tending to hold piston 50 in its solid line position will be dissipated through conduit 48, conduit 45, valve 44, conduit 46 and vent 58, and therefore spring 51 will expand substantially instantaneously to cause piston 50 to .return to its dotted line position which will cause the accompanying movement of valve element 53 to a position wherein conduit 159 thereof permits communication between conduit 56 and conduit 57 leading to sump 59 or a suitable other out-of-the-way place. As soon as valve 55 permits communication between

conduits

56 and 57, the high pressure of the water in conduit 60 will be dissipated and the water will be caused to travel to sump 59 and therefore be diverted from conduit 63 leading to lance 11. Thus in the event that lance 11 may be directed toward a person or object, there will not be a high pressure jet emanating from nozzle 12 which could produce either personal or property injury.

It is to be especially noted that pump 59' is not shut oifduring the foregoing action of valve 55 nor is any valve in conduit 60 closed. Therefore there will be no hydraulic ram or water hammer in any of the conduits because all that is done is that the high pressure water in conduit 60 leading from pump 59' is diverted to sump 59 instead of being caused to travel to lance 11 with its original high pressure.

It is also to be noted that there is no valve which closes in the compressed air line when lever 15 of grip valve 16 is released. More specifically, when valve 44 opens to permit chamber 49' of motor 49 to be vented through vent 58, the flow through conduits 47' and 37 leading to fluid pressure motor 49 and to hand grip valve 16, respectively, continues. However, there is not sufiicient pressure in these lines, notwithstanding the continuance of flow, to either actuate valve 39 or fluid pressure motor 49. More specifically, orifice union 36 (FIG. 5) contains a plate with metering orifice therein so that when aperture 22 (FIG. 3) of valve 16 is uncovered so that there can actually be flow through conduit 24 leading to valve 16, the orifice in orifice union 36 will cause a sufficient pressure drop between

conduits

35 and 37 to prevent the pressure in conduit 37 from being sufliciently high to cause the pressure in chamber 38 of valve 39 to cause diaphragm 41 to deflect against the bias of spring 42. Stated another way, it is only when valve element 21 closes aperture 22 (FIG. 3) that there can be a build up of static pressure in chamber 38 of valve 39 to cause valve 44 to close. In other words, when valve element 21 opens aperture 22, the flow of compressed air to valve 39 continues but it is not of suflicient magnitude to cause valve 44 to route compressed airto fluid pressure motor 49. The same is true of the flow through conduits 46' and 47. More specifically, an orifice union 65 is located between conduits 46 and 47. Whenever valve 44 beas the pressure in chamber 49' of fluid pressure motor 49, will not be of sufficient magnitude to move piston 50 from its dotted line position to its solid line position against the bias of the spring.

It can thus be seen that there are no valves closed when fluid pressure motor 49 is actuated to terminate either the flow of liquid in the system or to terminate the flow of compressed air. Therefore there can be no pneumatic shock or-hydraulic ram associated with the action of valve 44 in moving from a closed to an open position. In addition, it is again to be noted that valve 55 does not stop the high pressure flow of water through conduit 60 leading from pump 59' but merely diverts the water to sump 59 so that it is merely conducted to a place where it can be discharged at low pressure and the pressure of liquid leaving nozzle 12 of lance 11 is greatly reduced so that it cannot injure either personnel or property. It is again to be noted that when grip valve 16 is closed, that is, when it is brought to the position shown in FIG. 3, a build up of pressure in chamber 49 of fluid pressure motor 49 is very gradual because of the length of time that it takes for pressure to be built up in chamber 38 of valve 39 because of the action of orifice union 36 and further because of the length of time that it takes for pressure to be built up in chamber 49' of fluid pressure motor 49 because of the' action of orifice union 65.

In short, it thus can be seen that the pressure to lance 11 is built up gradually upon the closing of grip valve 16 but that this pressure is dissipated immediately if, for any reason, valve 16 should be opened, as when the operator loses control of the lance.

In FIG. 4 a modified type of valve construction is shown which may be used in lieu of valve 16. This valve 16' may be coupled to conduit 24 and comprises a foot switch wherein a lever is pivoted on pin 81 and may be moved in a clockwise direction about said pin against the bias of leaf spring 82 to thereby cause valve element 83 to cover aperture 84 in valve body 21'. A cover 85 is provided to encircle the toe of the lance operator. Valve 16 operates in a manner which is analogous to valve 16, described above.

In the aboveenumerated embodiments of the present invention the major portion of the components of the hydraulic and pneumatic circuitry for controlling the flow of high pressure liquid through the lance is situated at a position which is remote from the lance. Therefore, in essence, the subject matter of the present invention includes the advantage of permitting such components to be located at a position which is remote from the lance itself thereby obviating the necessity for the lance operator to physically carry such controls.

In FIGURES 6 and 7, an alternate embodiment of the present invention is disclosed. In this embodiment a system is presented for showing how a plurality of lances 11' may be operated from the same compressed air source 25' and from the same source of high pressure liquid, namely, pump 59" which draws this liquid from sump 58". At this point, it is to be noted that all the subject matter designated by primed numerals in FIG- URES 6 and 7 may be considered identical with the subject matter in the preceding figures having one less prime. It is believed that this code of nomenclature will greatly facilitate the ensuing description by minimizing surplusage.

Conduits 26' lead from compressed air source 25' to the controls 110'. Controls 110', for sake of ease of explanation, include the position 100 and a portion 101. Portion 100 includes all of the controls and related items of structure lying between

conduits

26, 48 and 24 of FIGURE 5, as indicated by dotted lines in FIGURE wherein

conduits

2s, 48 and 24, which are analogous to conduits 26', 48' and 24' of FIGURE 6, respectively, are shown leading to portion 100. Conduits 24' lead to valves 16' associated with each of lances 11' as described in detail above relative to lance 11 and control 16 (see FIG. 3). Conduits 56' are in communication with conduit 60 leading from pump 59" and these conduits 56 lead to control portion 101 (FIGS. 6- and 7). Within control portion 101 is a continuation of conduit 56' which communicates with conduits 102 and 103. The contents of control portion 101 are shown in FIG. 7.

At this juncture it is to be noted that the plurality of lances 16 of FIG. 6 each have a control 110' associated therewith. All of the lances 16' and the controls 110' are identical to their respective counterparts. As will become more aparent hereafter, each lance 16' has pressurized liquid supplied thereto, as dictated by the condition of the particular control 110 associated therewith. Each of the lances operates entirely independently of the others, but each lance and its associated control has structure which is identical to the others. Therefore, the specific structure and operation of only one lance 16 and its associated control 110" will be described.

Assuming that the controls 16' of each of the lances 11 is in a position which causes compressed air to be admitted to chamber 49" of air motor 49', as described in detail above relative to FIGS. 15, piston 50' of the latter will occupy its solid line position against the bias of spring 51' to thereby cause the piston stem 52 to actuate link 54' which in turn is attached to valve 53 in valve housing 55. An additional link 104 couples stem 52 to valve 105 in housing 106. Whenever each pneumatic control 16' of each lance 11 is depressed during normal lance operation, valves 53" and 5 will occupy the positions shown in FIG. 7 so that high pressure liquid in conduit 56' must pass through conduit 103, through valve 105, and thence through conduit 106 to lance 11'. Flow of high pressure hydraulic fluid through conduit 102 will be prevented because valve 53" is in the closed position.

However, in the event that anyone of controls 16' associated with each of lances 11 is manipulated by virtue of the operators losing control thereof, as described in detail above with respect to FIGURES 1-5, spring 51' within motor 49' will expand to return piston 50' to its dotted line position. As piston 50 moves to its dotted line position, it will move stem 52' and link 54' to cause valve 53 to approach an open position while link 104 causes valve 105 to approach a closed position. There will be a period during the actuation of valves 53' and 105 that both are open so that there will be a diminished flow to lance 11 through conduit 103 and an increased flow through conduits 102 and 107' to sump 59'. Continued movement of piston 50' to its final dotted line position in FIG. 7 will result in valve 105 closing completely and valve 53' opening completely. The closing of valve 105 will terminate flow of high pressure hydraulic fluid to lance 11' thereby performing the above described safety function of the present invention in a more positive manner than described above with respect to the apparatus of FIGURES 1-5. The opening of valve 53' will permit the high pressure pump fluid in conduit 56' to pass to sump 59' through

conduits

102 and 107.

It is to be especially noted that the resistance to liquid flow provided by valve 53' is the same as the resistance to liquid flow provided by valve 105. Thus, pressure will be maintained within conduit 56" and through conduit 60 leading to the other lance units notwithstanding that one of the lances has been turned off because the pressure drop across the control portion 101 (FIG. 7) associated with each of the lances is the same whether the lance is on or ofl. Thus, it can readily be seen that even if two of the three lances were turned ofl by their controls'16', the other lance would still be receiving the proper amount of hydraulic pressure to cause it to op erate efiiciently. Stated another way, the improved apparatus of FIGURES 6 and 7 permits a plurality of lances to be operated from a common hydraulic pressure source without the actual condition of operation of any one of the individual lances affecting the operation of the others to thereby permit a plurality of lance operators to operate in a manner which is unaffected by the actual mode of operation of the other operators.

It can thus be seen that the present invention is manifestly capable of achieving the above enumerated objects and while preferred embodiments have been disclosed, it will be understood that it may be otherwise embodied.

I claim:

1. A fluid pressure actuated control comprising first valve means for selectively causing fluid to flow in first and second paths, a fluid pressure motor for actuating said first valve means to a first position wherein it causes flow to an object through said first path and for actuating said first valve means to a second position wherein it directs flow of fluid away from said object through said second path, a source of fluid pressure, second valve means for eifectively directing fluid pressure from said source to said fluid pressure motor when said second valve means is in a first position and for venting said fluid pressure motor when said second valve means is in a second position, control means for causing said second valve means to be in either said first position or said second position, and means operatively associated with said second valve means for causing said fluid pressure to be built up gradually in said fluid pressure motor when said second valve means is moved to said first position to thereby cause said first valve means to be moved gradutlly to said first position, said means operatively associated with said second valve means permitting said fluid pressure motor to be vented through said second valve means substantially instantaneously without disconnecting said fluid pressure motor from said source of fluid pressure when said second valve means is in said second position to thereby cause said first valve means to be moved to said second position substantially instantaneously to thereby cause flow of said fluid through said second path.

2. Apparatus for removing incrustations by the use of a high pressure jet of liquid comprising in combination: a source of high pressure liquid, first means for projecting said high pressure liquid in a predetermined path, second means for conducting said high pressure liquid to said first means, and fluid pressure control means including first valve means located proximate said first means and second valve means actuatable by said first valve means and located at a remote position from said first means for automatically causing the pressure of said liquid to be built up gradually at said first means and for automatically causing the pressure of said liquid at said first means to be terminated substantially instantaneously without hydraulic shock.

3. A system for removing incrustations by the use of a high pressure jet of liquid comprising a lance for providing a jet of liquid, first valve means for selectively causing flow of said liquid in a first path to said lance and in a second path away from said lance, a fluid pressure motor for actuating said first valve means to a first position wherein it causes flow to said lance through said first path and for actuating said first valve means to a second position wherein it directs flow of said liquid away from said lance through said second path, second valve means for elfectively supplying pressurized fluid to said fluid pressure motor when said second valve means is in a first position and for venting said fluid pressure motor when said second valve means is in a second position, control meansvfor causing said second valve means to be in either said first position or said second position, and means operatively associated with said second valve means for causing said fluid pressure to be built up gradually in said fluid pressure motor when said second valve means is moved to said first position to thereby cause said first valve means to be moved gradually to said first position to thereby gradually direct pressurized liquid to said lance and thereby gradually build up the pressure of the jet of liquid emanating therefrom, said means operatively associated with said second valve means also permitting said fluid pressure motor to be vented through said second valve means substantially instantaneously without terminating communication between said fluid pressure motor and said source of fluid pressure when said second valve means is caused to move to said second position as a result of the operation of said control means, to thereby cause said first valve means to be moved to said second position substantially instantaneously to thereby cause flow of said liquid through said second path away from said lance without stopping the flow of liquid to thereby prevent hydraulic shock.

4. Apparatus for removing incrustations by the use of a high pressure jet of liquid comprising in combination: a lance, means for conducting liquid to said lance, and control means operatively associated with said lance for automatically causing the pressure of the liquid in said lance to be built up gradually to thereby permit an operator to have complete control of said lance during said pressure build up when said control means are actuated and for causing the flow of high pressure liquid through said lance to be terminated substantially instantaneously in response to the deactuation of said control means without subjecting said means for conducting fluid to said lance to hydraulic shock, said control means including manually movable first valve means which must be held in a first position by said operator to thereby effect said gradual build-up of pressure, and said control means including means associated with said manually movable first valve means for causing said manually movable first valve means to move to a second position to thereby cause said control means to substantially instantaneously terminate said flow of high pressure liquid to said lance,

said'control means including second valve means, and means for causing said second valve means to gradually supplyliquid to said lance upon actuation of said first valve means to said first position but which causes said second valve means to substantially instantaneously divert liquid from said lance upon movement of said first valve means to said second position.

5. Apparatus for removing incrustations by the use of a high pressure jet of liquid comprising in combination: a source of liquid, a lance for projecting said liquid in a desired path, means for conducting said liquid at high pressure to said lance; and control means operatively associated with said lance, said control means'comprising a source of fluid at a first pressure, means for reducing said first pressure to a second pressure which is less than said first pressure, a fluid pressure motor, conduit means for conducting fluid at said second pressure to said fluid pressure motor, first valve means operatively coupled to said fluid pressure motor, said first valve means causing said liquid to be delivered to-said lance at high pressure when said first valve means is in a first position in response to said fluid pressure motor being actuated by said fluid at said second pressure and for causing said liquid to be diverted away from said lance when the actuation of said fluid pressure motor by said fluid at said second pressure is terminated, means for reducing the pressure of said fluid to a third pressure whichris less than said second pressure, second valve means operatively associated with said lance for manipulation by a lance operator, said second valve means either confining said fluid at said third pressure or permitting it to be vented, means operatively associated with said second valve means for causing said fluid at said second pressure to be confined only when said second valve means are deliberately grasped by said lance operatorand permitting said second valve means to be automatically vented when said second valve means are not deliberately grasped by said lance operator, said third pressure being of a value which is relatively small so as to provide no substantial force against maintaining said fluid confined at said third pressure to thereby minimize the tiring of the operator resulting from grasping said second valve means, and

third valve means for causing fluid at said second pressure to be routed to said fluid pressure motor when said third valve means cause said fluid at said third pressure to be confined to thereby cause a gradual build up of fluid at said second pressure in said fluid pressure motor to thereby gradually actuate said first valve means to said first position to effect flow of high pressure liquid to said lance, said third valve means causing said fluid pressure motor to be vented substantially instantaneously in response to the venting of said second valve means in response to the release thereof by said lance operator to thereby divert the flow of liquid from said lance without stopping the flow of liquid, whereby said system is not subjected to hydraulic shock in response to the terminating of flow of said liquid to said lance.

6. Apparatus as set forth in claim 5 including means for permitting said fluid pressure motor to be vented in response to the action of said third valve means without terminating the flow of fluid at said second pressure.

7. A system for operating a plurality of high pressure incrustation removing lances from a common high pres sure source without the specific operational condition of any one of the lances aflecting any of the others comprising a plurality of lances, a high pressure hydraulic fluid source, conduit means coupling each of said lances to said hydraulic source, and a fluid actuated control means associated with each of said lances for controlling the flow of said hydraulic fluid toward said lances or away therefrom, each of said fluid actuated control means including fluid motor means, first valve means for permitting pressurized fluid to be supplied to said motor means, second and third valve means and associated conduits operatively coupled to said motor means with said second and third valve means occupying a position relative to each other which permits said hydraulic fluid to be routed to said lance when said second valve means are open and said third valve means are closed and to be blocked from said lance when said second valve means are closed and said third valve means are open, said second and third valve means and associated conduits being operatively interconnected to cause said second valve means to move toward a closed position when said third valve means moves toward an open position and to cause said second valve means to move toward an open position as said third valve means moves toward a closed position thereby causing the pressure drop of said hydraulic fluid to be substantially the same regardless of whether it passes through said second or third valve means or both whereby the pressure of said hydraulic fluid supplied to said other of said plurality of lances will not fluctuate appreciably when said second and third valve means associated with each of the other lances is moved between positions for routing hydraulic fluid to or in bypassing relationship to said lances.

8. A system as set forth in claim 7 including control means for causing said first valve means to be either in a first position for actuating said fluid pressure motor to a first position or causing said first valve means to be in a second position for actuating said fluid pressure motor to a second position, and means operatively associated with said first valve means for causing said fluid pressure motor to gradually move said second and third valve means to said open and closed positions, respectively, when said first valve means are actuated to said first position, said means operatively associated with said first valve means causing said motor means to substantially instantaneously move said second and third valve means to said closed and open positions, respectively, when said first valve means are actuated to said second position.

9. A system for operating a plurality of high pressure incrustation removing lances from a common high pressure source without the specific operational condition of any one of the lances aflecting any of the others comprising a plurality of lances, a high pressure hydraulic fluid source, conduit means coupling each of said lances to said hydraulic source, and a fluid actuated control means associated with each of said lances for controlling the flow of said hydraulic fluid toward said lances or away therefrom, each of said fluid actuated control means including fluid motor means, first valve means for permitting pressurized fluid to be supplied to said motor means, second and third valve means and associated conduits operatively coupled to said motor means with said second and third valve means occupying a position relative to each other which permits said hydraulic fluid to be routed to said lance and to be blocked from said lance, said second and third valve means and associated conduits causing the pressure drop ofsaid hydraulic fluid to be the same regardless of whether it passes through said second or third valve means whereby the pressure of said hydraulic fluid supplied to said other of said plurality of lances will not fluctuate appreciably when said second and third valve means associated with each of the other lances is moved between positions for routinghydraulic fluid to or in bypassing relationship to said lances, said second and third valve means in moving between opened and closed positions occupying a position wherein both of said second and third valve means are simultaneously open to thereby effect an orderly transition between the routing of said high pressure hydraulic fluid to and from said lance without effecting hydraulic shock in said system, said fluid actuated control means including a source of compressed air and conduit means for conducting said compressed air to said first valve means, said first valve means causing a build-up of pressure when closed, pressure responsive fourth valve means for placing said source of compressed air in communication with said motor means when said first valve means is closed to thereby cause said motor means to open said second valve means and close said third valve means to thereby permit said high pressure hydraulic fluid to be supplied to said lance, and means for causing said fourth valve means in said control to dump compressed fluid from said motor means instantaneously upon release of said first valve means to thereby cause said motor means to effect said transition between closing said second valve means leading to said lance and opening said third valve means bypassing said lance.

10. A fluid pressure actuated control comprising first valve means for selectively causing fluid to flow in first and second paths, a fluid pressure motor for actuating said first valve means to a first position wherein it causes flow to an object through said first path and for actuating said first valve means vto a second position wherein it directs flow of fluid away from said object through said second path, a source of fluid pressure, second valve means in communication with said source for actuating said fluid pressure motor to a first position when said second valve means is in a first position and for actuating said fluid pressure motor to a second position when said second valve means is in a second position, control means for causing said second valve means to be in either said first position or said second position, and means operatively associated with said second valve means for causing said fluid pressure motor to move said first valve means gradually to said first position when said second valve means is moved to said first position, said means operatively associated with said second valve means causing said fluid pressure motor to move said first valve means abruptly to said second position when said second valve means is moved to said second position to thereby cause substantially instantaneous flow of said fluid through said second path away from said object to thereby prevent hydraulic shock.

11. A system for removing incrustations by the use of a high pressure jet of fluid comprising a lance for providing a jet of fluid, first valve means for selectively causing flow of said fluid in a first path to said lance and in a second path away from said lance, a fluid pressure motor for actuating said first valve means to a first position wherein it causes fiow to said lance through said first path and for actuating said first valve means to a second position wherein it directs flow of said fluid away from said lance through said second path, second valve means for actuating said fluid pressure motor to a first position when said second valve means is in a first position and for actuating said fluid pressure motor to a second position when said second valve means is in a second position, control means for causing said second valve means to be either in said first position or said second position, andmeans operatively associated with said second valve means for causing said fluid pressure motor to move said first valve means gradually to said first position when said second valve means is moved to said first position to thereby gradually direct pressurized fluid to said lance and thereby gradually build up the pressure of the jet of fluid emanating from said lance, said means operatively associated with said second valve means causing said fluid pressure motor to move said first valve means quickly to said second position when said second valve means is moved to said second position to thereby cause substantially instantaneous flow of fluid through said second path away from said lance without stopping the flow of fluid to thereby prevent fluid shock.

12. A system for removing incrustations by the use of a high pressure jet of fluid comprising a lance for providing a jet of fluid, first valve means for selectively causing flow of said fluid in a first path to said lance and in a second path away from said lance, motor means for actuating said first valve means to a first position wherein vit causes flow to said lance through said first path and for actuating said first valve means to a second position wherein it directs flow of said fluid away from said lance through said second path, motor energizing means for actuating said motor means to a first position when said motor energizing means is in a first position and for actuating said motor means to a second position when said motor energizing means is in a second position, and means operatively associated with said motor energizing means for causing said motor means to move said first valve means gradually to said first position when said motor energizing means is moved to said first position to thereby gradually direct pressurized fluid to said lance and thereby gradually, build up the pressure of the jet of fluid emanating from said lance, said means operatively associated with said motor energizing means causing said motor means to move said first valve means quickly to said second position when said motor energizing means is moved to said second position to thereby cause substantially instantaneous flow of fluid through said second path away from said lance without stopping the flow of fluid to thereby prevent fluid shock.

References Cited by the Examiner UNITED STATES PATENTS EVERETT w. KIRBY, Primary Examiner.

Claims

2. APPARATUS FOR REMOVING INCRUSTATIONS BY THE USE OF A HIGH PRESSURE JET OF LIQUID COMPRISING A COMBINATION: A SOURCE OF HIGH PRESSURE LIQUID, FIRST MEANS FOR PROJECTING SAID HIGH PRESSURE LIQUID IN A PREDETERMINED PATH, SECOND MEANS FOR CONDUCTING SAID HIGH PRESSURE LIQUID TO SAID FIRST MEANS, AND FLUID PRESSURE CONTROL MEANS INCLUDING FIRST VALVE MEANS LOCATED PROXIMATER SAID FIRST MEANS AND SECOND VALVE MEANS ACTUATABLE BY SAID FIRST VALVE MEANS AND LOCATED AT A REMOTE POSITION FROM SAID FIRST MEANS FOR AUTOMATICALLY CAUSING THE PRESSURE OF SAID LIQUID TO BE BUILT UP GRADUALLY AT SAID FIRST MEANS AND FOR AUTOMATICALLY CAUSING THE PRESSURE OF SAID LIQUID AT SAID FIRST MEANS TO BE TERMINATED SUBSTANTIALLY INSTANTANEOUSLY WITHOUT HYDRAULIC SHOCK.