Pumping system for mobile protective coating spray apparatus and other applications

• US 4,684,062 A
• Filed: 06/28/1985
• Issued: 08/04/1987
• Est. Priority Date: 06/28/1985
• Status: Expired due to Fees

• Current Assignee: Neal Manufacturing Company
• Original Assignee: Neal Manufacturing Co., Inc. (Blastcrete Equipment Company, Inc.)
• Inventors: Bagwell, Maury L.
• Primary Examiner(s): Kashnikow, Andres
• Assistant Examiner(s): Forman, Michael J.
• Application Number:
  US06/749,759
• Time in Patent Office: 767 Days
• Field of Search: 239/159, 239/163, 239/164, 239/169, 239/172, 239/175, 239/1, 239/11, 239/332, 417/403, 91/275
• US Class Current: 239/1
• CPC Class Codes: B05B 9/0409 the pumps being driven by a hydraulic or a pneumatic fluid
• CPC Class Codes: E01C 19/174 Apparatus with pump-discharge

Abstract

Disclosed herein is an improved pumping system for self-contained and, if desirable, portable machines adapted to efficiently spray or squeegee viscous sealing fluids on roadway pavement and parking lots, which fluids may contain suspended solid matter. For example, this fluid pumping assembly is especially suitable for spraying asphaltic or coal-tar-pitch emulsions containing sand onto asphalt road surfaces. Also disclosed is an improved hydraulic drive cylinder assembly and control means therefor employing an improved electrically controlled hydraulically operated drive network.

Claims

1. A hydraulic drive cylinder assembly comprising top and bottom manifolds and a hydraulic cylinder tube mounted therebetween fabricated of non-magnetic material, said manifolds having hydraulic oil communication ports formed therein, a hydraulic piston within the said hydraulic cylinder tube comprising, at least in part, magnetic material;

upper and lower magnetic-responsive reed-type proximity limit switches positioned at either end of said cylinder and electrically responsive through combination electric network means and hydraulic network means to the presence of the magnetic material in the hydraulic piston to alternately activate solenoid valve means connected to hydraulic pressure generating means from a first position in which said solenoid valve means directs said hydraulic piston in one direction to a second solenoid valve means position in which said solenoid valve means directs said hydraulic piston in the other direction of a reciprocating cycle, said solenoid valve means having selectively communicating hydraulic oil passageways on the exterior surface thereof in matching alignment with selectively communicating hydraulic oil passageways formed in said top manifold, said solenoid valve means being mounted immediately juxtaposition to and integrally and contiguously with said top manifold by fastener means to provide selectively communicating hydraulic oil pathways between said top manifold and said solenoid valve means, thus ease of replacement is facilitated, interchangeability and serviceability are improved, and requirements for hard electrical wiring and hydraulic drive cylinder assembly component space requirements are reduced.

12. The invention of claim 1 wherein said solenoid valve is detachably mounted directly onto the side of a manifold of said hydraulic drive cylinder assembly and hydraulic pathway interconnection is made between said solenoid valve and said manifold through oppositely facing, selectively communicating hydraulic oil ports on the exterior surfaces of said solenoid valve and said manifold.

2. A materials pumping system comprising:

a double acting piston pump comprising upper and lower plunger assemblies comprising, respectively, an upper plunger and a lower plunger;

said pump being mounted for vertical reciprocation responsive to a mechanical force;

combination electrical network means and hydraulic network means to provide said mechanical force;

magnetically responsive proximity switch means linked together in direct electrical series connection and forming, in combination with electrical relay assembly means and solenoid directional control valve means, at least part of said electrical network means;

said proximity switch means comprising one normally open switch means and one normally closed switch means;

said combination electrical network means and hydraulic network means being provided with means to alternately act through said magnetically responsive proximity switch means and said direct electrical series connection to provide alternating signals to reciprocating motive force means to reciprocate said piston pump by detecting the presence of magnetic piston means within a hydraulic cylinder as part of said network means;

alternate detection of the presence of said magnetic piston means by said proximity switch means acting through said electrical network means and said hydraulic network means to continuously reciprocate said piston pump.

3. The invention of claim 2 wherein said upper plunger assembly and said lower plunger assembly are interconnected by a pump shaft, said lower plunger assembly comprising a pumping head cage, a check ball, and leather seals separated by spacers and sealingly engaging the sides of a lower pump housing.

4. The invention of claim 3 wherein, for most efficient and consistent operation, said pump is vertically mounted on an axis approximately perpendicular to the center of the earth whereby said plunger assemblies are operable to pump material to a spray means incorporating a spray nozzle with a flat, wide-angle spray pattern.

7. The control network of claim 4 wherein said solenoid valve means is detachably mounted directly onto the side of a manifold of said hydraulic drive cylinder means, said manifold being mounted on said hydraulic drive cylinder tube and enclosing one end of one chamber thereof, and hydraulic pathway control and interconnection is made between said solenoid valve and said manifold through oppositely facing, selectively communicating hydraulic oil ports on the exterior surfaces of said solenoid valve means and said manifold.

5. A materials pumping system for viscous materials comprising:

a double acting piston pump comprising an upper pump housing mounting an upper plunger assembly for reciprocation therein and a lower pump housing mounting a combination lower plunger assembly and pumping head cage for reciprocation therein, a pump shaft connecting said upper plunger assembly to said pumping head cage and said lower plunger assembly;

said plunger assemblies and pump shaft being mounted for vertical reciprocation, both said plunger assemblies having seal means acting in sliding engagement with inside housing surfaces of their respective pump housings, said upper pump housing being open to the atmosphere at an upper end thereof,

pump reciprocating drive means comprising a hydraulic drive cylinder assembly connected by a piston rod to the upper plunger assembly and also to the lower plunger assembly;

combination electrical network means and hydraulic network means to provide means to reciprocate said pump;

magnetically responsive proximity switch means located juxtaposition said hydraulic drive cylinder assembly near opposite ends thereof to provide reciprocating control means for said drive cylinder assembly;

control network means comprising said proximity switch means, solenoid directional valve means and electrical relay assembly means;

said control network means being actuated responsive to the physical location of a ferro-magnetic drive piston within said hydraulic drive cylinder assembly to alternately actuate said proximity switch means to reciprocate said pump,

said control network means further comprising means to protect the seal means of said upper plunger assembly from being damaged from contact with encrusted viscous material which may harden on the inside surface of said upper pump housing, said further means to protect comprising means comprising part of said control network means to positively return said drive piston and said upper and lower plunger assemblies to their uppermost reciprocating positions when said control network means is deactuated to thereby prohibit said upper plunger assembly from coming to rest in another position and to thereby protect the seal means of the upper plunger assembly.

6. An improved control network for hydraulic drive cylinder means comprising:

a non-magnetic hydraulic drive cylinder tube containing magnetic piston means and piston shaft means slidingly mounted therein for linear reciprocation, said piston means dividing said tube into upper and lower chambers for alternately receiving hydraulic fluid to drive said piston means in first one direction and then the other direction to achieve reciprocation of said piston shaft,

one normally open proximity limit switch means having two electrical leads, said switch being located near one end of said non-magnetic cylinder tube,

one normally closed proximity limit switch means having two electrical leads, said last mentioned switch means being located near the other end of said non-magnetic cylinder tube,

one electrical lead of said normally open switch directly electrically series connected to one electrical lead of said normally closed switch,

electrical relay assembly means electrically connecting said series connected proximity switches and also electrically connected to solenoid directional control valve means and a direct current power source, said electrical relay assembly means comprising relay coil means to actuate throw switch assembly means to alternately energize and deenergize said solenoid directional control valve means responsive to alternating electrical signals from said proximity switch means,

said proximity limit switch means, said electrical relay assembly means, said direct electrical series connection between said proximity switch means, said direct current power source and said solenoid directional control valve means comprising an electrical network,

said solenoid valve means operable in a hydraulic network supplying hydraulic fluid from a variable volume pressure compensated hydraulic pump to a first chamber of said drive cylinder when said solenoid valve means is in a first position and to a second chamber of said drive cylinder when said solenoid valve means is in a second position,

said magnetic piston and piston shaft of said drive cylinder being continuously reciprocated through the operation and interaction of the combination hydraulic network and electric network, which two networks together comprise a control network,

to drive work means requiring a reciprocating power stroke

8. A portable apparatus for spraying asphalt or coal-tar-pitch emulsions comprising:

a reservoir containing said emulsion, a fluid pumping assembly vertically mounted on said apparatus and comprised of a hydraulic drive cylinder assembly, a vertical lift double acting piston pump comprising an upper pump housing containing an upper plunger assembly, a lower pump housing containing a lower plunger assembly, said lower plunger assembly comprising pumping head cage means containing an upper check ball valve, the lower end of said double acting piston pump having lower check ball valve means;

said upper plunger assembly and said lower plunger assembly being substantially coaxially aligned,

a pump shaft coaxially aligned with, connected to, and powered by a movable reciprocating hydraulic piston and piston rod within said hydraulic drive cylinder, said pump shaft also being substantially coaxially aligned with and connected to said upper and lower plunger assemblies,

said hydraulic drive cylinder having upper and lower ends and being fabricated of non-magnetic material and a hydraulic piston mounted for reciprocation within said hydraulic drive cylinder comprising, at least in part, magnetic material,

an upper, normally open proximity switch mounted on said hydraulic drive cylinder near one end thereof, and a second, normally closed proximity switch mounted on said hydraulic drive cylinder near the other end thereof, said normally open proximity switch being directly electrically series connected to said normally closed proximity switch,

said upper and lower proximity switches being electrically responsive through combination electric network means and hydraulic network means to the magnetic material of said hydraulic piston to reciprocate said piston by alternately activating solenoid directional control valve means comprising part of said hydraulic network means to continuously alternate the directional flow of hydraulic fluid supplied by a hydraulic pressure-generating means to opposite ends of said hydraulic drive cylinder,

said solenoid directional control valve means occupying a first position when said proximity switches are in their respective normal positions to thereby direct hydraulic fluid to one end of said hydraulic drive cylinder to move said piston in a first direction,

said normally open proximity switch closing in a second position in response to the presence of said magnetic material of said piston to complete electric network means through said direct electrical series connection between said proximity switches to activate said solenoid control valve means to a second position to direct hydraulic fluid to the other end of said hydraulic drive cylinder,

said electric network means and said hydraulic network means acting together to alternately reciprocate said piston, said pump shaft and said plunger assemblies.

9. The apparatus for spraying of claim 8 wherein said solenoid valve means is detachably mounted directly onto the side of a manifold of said hydraulic drive cylinder assembly, said manifold being mounted on said hydraulic drive cylinder and enclosing one end of said cylinder, and hydraulic pathway control and interconnection is made between said solenoid valve means and said manifold through oppositely facing, selectively communicating hydraulic oil ports on the exterior surfaces of said solenoid valve means and said manifold.

10. A method for controlling the flow and pressure requirements of apparatus for spraying asphalt or coal-tar-pitch emulsion material comprising:

providing a reservoir containing said emulsion,

providing spray means for spraying said emulsion,

providing an on-off valve means for controlling the flow of emulsion to said spray means,

providing pumping means for pumping said emulsion through discharge line means to said on-off valve and thence to said spray means,

providing hydraulic drive cylinder means to reciprocate a materials pump and thereby pump said emulsion to said spray means,

controlling and operating said apparatus so that the discharge volume of emulsion at the spray means is less than the pressure and volume of emulsion being generated and supplied by the materials pump thus creating an "over supply" of emulsion in said discharge line upstream of said on-off valve, the resulting rise in material pressure within said materials pump causing a corresponding rise in hydraulic pressure in the hydraulic drive cylinder means,

providing variable volume pressure compensated hydraulic pump means controlled and actuated by electrical circuit means to reciprocate said hydraulic drive cylinder means, said hydraulic pump means and said hydraulic cylinder means comprising hydraulic fluid system means,

providing sensing means and operating said apparatus for spraying so that said rise in hydraulic pressure in said hydraulic drive cylinder means causes said variable volume pressure compensated hydraulic pump to reduce its volume of a hydraulic oil being pumped and supplied to said hydraulic drive cylinder means so as to maintain a preset, maximum compensated pressure (e.g. 650 psi) in the hydraulic fluid system means, said reduction in volume in turn reducing the hydraulic oil supply to the reciprocating hydraulic drive cylinder means thereby causing the drive cylinder means to reduce its speed of reciprocation, thereby in turn reducing and regulating the speed of the materials pump driven by said hydraulic drive cylinder means which in turn decreases the materials pressure in the discharge line thereby controlling said discharge line pressure to a maximum preset emulsion material pressure of, for example, approximately 70 psi, which corresponds to a maximum preset design pressure in the hydraulic fluid system means of, for example, the previously mentioned 650 psi, whereby when the apparatus for spraying emulsion is again turned on at the on-off valve by the operator, the emulsion pressure immediately falls activating said sensing means and causing the variable volume pressure compensated hydraulic pump to again begin to supply the hydraulic drive cylinder with hydraulic oil to automatically maintain material pressure in response to the volume of material flow.

11. An improved hydraulic drive cylinder control network for a hydraulic drive cylinder assembly comprising:

a non-magnetic hydraulic drive cylinder tube containing a magnetic piston and piston shaft slidingly mounted therein for linear reciprocation,

one normally open proximity limit switch having at least two electrical leads, said switch being located near one end of said non-magnetic cylinder tube and said open switch moving to a closed position responsive to close physical proximity to said magnetic piston,

one normally closed proximity limit switch having at least two electrical leads, said last mentioned switch being located near the other end of said non-magnetic cylinder tube and said closed switch moving to an open position responsive to close physical proximity to said magnetic piston,

one electrical lead of said normally open proximity limit switch being connected in a direct electrical series connection to one electrical lead of said normally closed proximity limit switch,

an electrical relay assembly means having relay coil means directly electrically connected to a second electrical lead of said normally closed proximity limit switch, said relay coil means also being electrically connected to a direct current power source,

said electrical relay assembly means also comprising switch assembly means electrically connected to a second electrical lead of said normally open proximity limit switch, said switch assembly means also electrically connected to a solenoid directional control valve and said direct current power source,

said proximity limit switches, said electrical relay assembly means, said relay coil means, said switch assembly means, said direct current power source, said solenoid directional control valve, and said electrical connections comprising an electrical network for said hydraulic drive cylinder assembly,

said solenoid valve operable in a hydraulic network supplying hydraulic fluid from a hydraulic oil pump to a first chamber of said drive cylinder when said solenoid valve is in a first position and to a second chamber of said drive cylinder when said solenoid valve is in a second position,

said magnetic piston and piston shaft of said drive cylinder being actuated through the operation and interaction of the combination hydraulic network and electric network, which two networks together comprise a control network,

to drive work means requiring a reciprocating power stroke.

13. An improved hydraulic drive cylinder control network for a hydraulic drive cylinder assembly comprising:

a non-magnetic hydraulic drive cylinder tube containing a magnetic piston and piston shaft slidingly mounted therein for linear reciprocation,

one normally open proximity limit switch located near one end of said non-magnetic cylinder tube,

one normally closed proximity limit switch located near the other end of said non-magnetic cylinder,

said proximity limit switches being directly electrically connected in electrical series,

an electrical relay assembly electrically connected to said proximity switches and also electrically connected to a solenoid directional control valve,

said proximity limit switches, said direct electrical series connection between said proximity switches, said relay assembly, and said solenoid directional control valve comprising an electrical network,

said solenoid valve operable in a hydraulic network supplying hydraulic oil from a variable volume pressure compensated hydraulic pump to a first chamber of said drive cylinder when said solenoid valve is in a first position and to a second chamber of said drive cylinder when said solenoid valve is in a second position,

said variable volume pressure compensated hydraulic pump being set to run at a constant, pre-set speed, the volume displacement of hydraulic oil of said pump being controlled by adjustable valve means located in said hydraulic network between said pump and said solenoid valve, adjustment of said valve means providing variable speed regulation of the speed of reciprocation of said magnetic piston within said hydraulic drive cylinder assembly,

said magnetic piston and piston shaft of said drive cylinder being actuated through the operation and interaction of the combination hydraulic network and electric network, which two networks together comprise the improved hydraulic drive cylinder control network,

to drive work means requiring a reciprocating power stroke.

14. The invention of claim 13 wherein said adjustable valve means comprises an adjustable needle valve, adjustment of said needle valve providing a speed control means for controlling the speed of reciprocation of said hydraulic drive cylinder assembly, said speed control means possessing an infinite intermediate speed regulation, for example, between 0 and 60 cycles per minute.

15. The invention of claim 14 wherein said hydraulic network further comprises bypass line means and relief valve means in said bypass line means, said bypass line means and said relief valve means linking the output of said variable volume pressure compensated hydraulic pump and a hydraulic oil reservoir to provide safe operation of said hydraulic network.

16. The control network of claim 13 wherein said solenoid valve is detachably mounted directly onto the side of a manifold of said hydraulic drive cylinder assembly, said manifold being mounted on said hydraulic drive cylinder and enclosing one end of said cylinder, and hydraulic pathway control and interconnection is made between said solenoid valve and said manifold through oppositely facing, selectively communicating hydraulic oil ports on the exterior surfaces of said solenoid valve and said manifold.

17. An improved hydraulic drive cylinder control network for a hydraulic drive cylinder assembly comprising:

a non-magnetic hydraulic drive cylinder tube containing a magnetic piston and piston shaft slidingly mounted therein for linear reciprocation,

one normally open proximity limit switch having at least two electrical leads, said switch being located near one end of said non-magnetic cylinder tube,

one normally closed proximity limit switch having at least two electrical leads, said last mentioned switch being located near the other end of said non-magnetic cylinder tube,

one electrical lead of said normally open proximity limit switch being connected in a direct electrical series connection to one electrical lead of said normally closed proximity limit switch,

an electrical relay assembly means having relay coil means directly electrically connected to a second electrical lead of said normally closed proximity limit switch, said relay coil means also being electrically connected to a direct current power source,

said electrical relay assembly means also comprising switch assembly means electrically connected to a second electrical lead of said normally open proximity limit switch, said switch assembly means also electrically connected to a solenoid directional control valve and said direct current power source.

said proximity limit switches, said electrical relay assembly means, said relay coil means, said switch assembly means, said direct current power source, said solenoid directional control valve, and said electrical connections comprising an electrical network for said hydraulic drive cylinder assembly,

said electrical relay assembly means and said proximity switches being mounted within and below a smooth exterior surface of an electronic control board, and, said control board, said solenoid valve, and said drive cylinder being assembled in one self-contained, contiguous, integral and juxtapositioned assembly whereby ease of replacement of said assembly is facilitated, interchangeability and serviceability are improved, and requirements for hard electrical wiring and hydraulic drive cylinder assembly component space are reduced,

said solenoid valve operable in a hydraulic network supplying hydraulic fluid from a hydraulic oil pump to a first chamber of said drive cylinder when said solenoid valve is in a first position and to a second chamber of said drive cylinder when said solenoid valve is in a second position,

said magnetic piston and piston shaft of said drive cylinder being actuated through the operation and interaction of the combination hydraulic network and electric network, which two networks together comprise a control network,

to drive work means requiring a reciprocating power stroke.

18. The control network of claim 17, wherein said normally open and normally closed proximity switches are magnet-responsive reed-type switches.

19. An improved hydraulic drive cylinder control network for a hydraulic drive cylinder assembly comprising:

a non-magnetic hydraulic drive cylinder tube containing a magnetic piston and piston shaft slidingly mounted therein for linear reciprocation,

one normally open proximity limit switch having at least two electrical leads, said switch being located near one end of said non-magnetic cylinder tube,

one normally closed proximity limit switch having at least two electrical leads, said last mentioned switch being located near the other end of said non-magnetic cylinder tube,

one electrical lead of said normally open proximity limit switch being connected in a direct electrical series connection to one electrical lead of said normally closed proximity limit switch,

an electrical relay assembly means having relay coil means directly electrically connected to a second electrical lead of said normally closed proximity limit switch, said relay coil means also being electrically connected to a direct current power source,

said electrical relay assembly means also comprising switch assembly means electrically connected to a second electrical lead of said normally open proximity limit switch, said switch assembly means also electrically connected to a solenoid directional control valve and said direct current power source,

said proximity limit switches, said electrical relay assembly means, said relay coil means, said switch assembly means, said direct current power source, said solenoid directional control valve, and said electrical connections comprising an electrical network for said hydraulic drive cylinder assembly,

said solenoid valve operable in a hydraulic network supplying hydraulic fluid from a hydraulic oil pump to a first chamber of said drive cylinder when said solenoid valve is in a first position and to a second chamber of said drive cylinder when said solenoid valve is in a second position,

said magnetic piston and piston shaft of said drive cylinder being actuated through the operation and interaction of the combination hydraulic network and electric network, which two networks together comprise a control network,

20. to drive work means requiring a reciprocating power stroke,

and means within the control network to return said magnetic piston to a position retracted within said drive cylinder assembly when said solenoid valve and said electrical relay assembly means are deenergized to thereby achieve a desired and predetermined condition in said work means when said magnetic piston is stopped at a selected end of its stroke.

21. An improved hydraulic drive cylinder control network for a hydraulic drive cylinder assembly comprising:

a non-magnetic hydraulic drive cylinder tube containing a magnetic piston and piston shaft slidingly mounted therein for linear reciprocation,

one normally open proximity limit switch having at least two electrical leads, said switch being located near one end of said non-magnetic cylinder tube,

one normally closed proximity limit switch having at least two electrical leads, said last mentioned switch being located near the other end of said non-magnetic cylinder tube,

one electrical lead of said normally open proximity limit switch being connected in a direct electrical series connection to one electrical lead of said normally closed proximity limit switch,

an electrical relay assembly means having relay coil means directly electrically connected to a second electrical lead of said normally closed proximity limit switch, said relay coil means also being electrically connected to a direct current power source,

said electrical relay assembly means also comprising switch assembly means electrically connected to a second electrical lead of said normally open proximity limit switch, said switch assembly means also electrically connected to a solenoid directional control valve and said direct current power source,

said proximity limit switches, said electrical relay assembly means, said relay coil means, said switch assembly means, said direct current power source, said solenoid directional control valve, and said electrical connections comprising an electrical network for said hydraulic drive cylinder assembly,

said solenoid valve operable in a hydraulic network supplying hydraulic fluid from a hydraulic oil pump to a first chamber of said drive cylinder when said solenoid valve is in a first position and to a second chamber of said drive cylinder when said solenoid valve is in a second position,

said switch assembly means comprising a double pole double throw switch, said throw switch being alternately actuatable into a make-contact electrical circuit position and a break-contact open circuit position respectively when said solenoid valve is respectively in said solenoid valve'"'"'s second position and said solenoid valve'"'"'s first position,

said magnetic piston and piston shaft of said drive cylinder being actuated through the operation and interaction of the combination hydraulic network and electric network, which two networks together comprise a control network,

to drive work means requiring a reciprocating power stroke.

22. An improved hydraulic drive cylinder control network for a hydraulic drive cylinder assembly comprising:

a non-magnetic hydraulic drive cylinder tube containing a magnetic piston and piston shaft slidingly mounted therein for linear reciprocation,

one normally open proximity limit switch having at least two electrical leads, said switch being located near one end of said non-magnetic cylinder tube,

one normally closed proximity limit switch having at least two electrical leads, said last mentioned switch being located near the other end of said non-magnetic cylinder tube,

one electrical lead of said normally open proximity limit switch being connected in a direct electrical series connection to one electrical lead of said normally closed proximity limit switch,

an electrical relay assembly means having relay coil means directly electrically connected to a second electrical lead of said normally closed proximity limit switch, said relay coil means also being electrically connected to a direct current power source,

said electrical relay assembly means also comprising switch assembly means electrically connected to a second electrical lead of said normally open proximity limit switch, said switch assembly means also electrically connected to a solenoid directional control valve and said direct current power source,

said proximity limit switches, said electrical relay assembly means, said relay coil means, said switch assembly means, said direct current power source, said solenoid directional control valve, and said electrical connections comprising an electrical network for said hydraulic drive cylinder assembly,

said solenoid valve operable in a hydraulic network supplying hydraulic fluid from a hydraulic oil pump to a first chamber of said drive cylinder when said solenoid valve is in a first position and to a second chamber of said drive cylinder when said solenoid valve is in a second position,

and positive reciprocation means for eliminating stalling of the magnetic piston means in mid-stroke and for returning said magnetic piston means to an up-stroke position when said solenoid valve and said electrical relay assembly means are deenergized, said positive reciprocation means comprising a single solenoid directional control valve assembly of the two position spring offset type, said single solenoid directional control valve being biased in a normal, deenergized position when said electrical relay assembly means is also in a deenergized position, to provide hydraulic fluid flow through said solenoid valve from said hydraulic pump to said lower chamber of said drive cylinder tube to thereby raise said magnetic piston means to the up-stroke position when said solenoid valve and said relay assembly means are electrically deenergized,

said magnetic piston and piston shaft of said drive cylinder being actuated through the operation and interaction of the combination hydraulic network and electric network, which two networks together comprise a control network,

to drive work means requiring a reciprocating power stroke.

23. An improved hydraulic drive cylinder control network for a hydraulic drive cylinder assembly comprising:

a non-magnetic hydraulic drive cylinder tube containing a magnetic piston and piston shaft slidingly mounted therein for linear reciprocation,

one normally open proximity limit switch having at least two electrical leads, said switch being located near one end of said non-magnetic cylinder tube,

one normally closed proximity limit switch having at least two electrical leads, said last mentioned switch being located near the other end of said non-magnetic cylinder tube,

one electrical lead of said normally open proximity limit switch being connected in a direct electrical series connection to one electrical lead of said normally closed proximity limit switch,

an electrical relay assembly means having relay coil means directly electrically connected to a second electrical lead of said normally closed proximity limit switch, said relay coil means also being electrically connected to a direct current power source,

said electrical relay assembly means also comprising switch assembly means electrically connected to a second electrical lead of said normally open proximity limit switch, said switch assembly means also electrically connected to a solenoid directional control valve and said direct current power source,

and electrical latching (i.e. self-holding) means for maintaining said switch assembly means in a closed position even after said magnetic piston leaves the magnetic proximity of said normally open proximity limit switch, said latching means holding said switch assembly means in said closed position until such time as said magnetic piston comes into the proximity of said normally closed proximity switch, whereupon said electrical latching means is released,

said proximity limit switches, said electrical relay assembly means, said relay coil means, said switch assembly means, said electrical latching (i.e. self-holding) means, said direct current power source, said solenoid directional control valve, and said electrical connections comprising an electrical network for said hydraulic drive cylinder assembly,

said solenoid valve operable in a hydraulic network supplying hydraulic fluid from a hydraulic oil pump to a first chamber of said drive cylinder when said solenoid valve is in a first position and to a second chamber of said drive cylinder when said solenoid valve is in a second position,

said magnetic piston and piston shaft of said drive cylinder being actuated through the operation and interaction of the combination hydraulic network and electric network, which two networks together comprise a control network,

to drive work means requiring a reciprocating power stroke.

24. An improved hydraulic drive cylinder control network for a hydraulic drive cylinder assembly comprising:

a non-magnetic hydraulic drive cylinder tube containing a magnetic piston and piston shaft slidingly mounted therein for linear reciprocation,

one normally open proximity limit switch having at least two electrical leads, said switch being located near one end of said non-magnetic cylinder tube,

one normally closed proximity limit switch having at least two electrical leads, said last mentioned switch being located near the other end of said non-magnetic cylinder tube,

one electrical lead of said normally open proximity limit switch being connected in a direct electrical series connection to one electrical lead of said normally closed proximity limit switch,

an electrical relay assembly means having relay coil means directly electrically connected to a second electrical lead of said normally closed proximity limit switch, said relay coil means also being electrically connected to a direct current power source,

said electrical relay assembly means also comprising switch assembly means electrically connected to a second electrical lead of said normally open proximity limit switch, said switch assembly means also electrically connected to a solenoid directional control valve and said direct current power source,

said proximity limit switches, said electrical relay assembly means, said relay coil means, said switch assembly means, said direct current power source, said solenoid directional control valve, and said electrical connections comprising an electrical network for said hydraulic drive cylinder assembly,

said proximity switches and said electrical relay assembly means being physically consolidated and mounted within and below a smooth exterior surface of an electronic directional control board which is physically mounted in juxtaposition to and contiguously with said hydraulic drive cylinder assembly to thereby facilitate ease of replacement and to improve interchangeability and serviceability in field-use situations,

said solenoid valve operable in a hydraulic network supplying hydraulic fluid from a hydraulic oil pump to a first chamber of said drive cylinder when said solenoid valve is in a first position and to a second chamber of said drive cylinder when said solenoid valve is in a second position,

said magnetic piston and piston shaft of said drive cylinder being actuated through the operation and interaction of the combination hydraulic network and electric network, which two networks together comprise a control network,

to drive work means requiring a reciprocating power stroke.

25. An improved control network for hydraulic drive cylinder means comprising:

a non-magnetic hydraulic drive cylinder tube containing magnetic piston means and piston shaft means slidingly mounted therein for linear reciprocation, said piston means dividing said tube into upper and lower chambers for alternately receiving hydraulic fluid to drive said piston means in first one direction and then the other direction to achieve reciprocation of said piston shaft,

one normally open proximity limit switch means having two electrical leads, said switch being located near one end of said non-magnetic cylinder tube,

one normally closed proximity limit switch means having two electrical leads, said last mentioned switch means being located near the other end of said non-magnetic cylinder tube,

one electrical lead of said normally open switch directly electrically series connected to one electrical lead of said normally closed switch,

electrical relay assembly means electrically connecting said series connected proximity switches and also electrically connected to solenoid directional control valve means and a direct current power source, said electrical relay assembly means comprising relay coil means to actuate throw switch assembly means to alternately energize and deenergize said solenoid directional control valve means responsive to alternating electrical signals from said proximity switch means,

said proximity limit switch means, said electrical relay assembly means, said direct electrical series connection between said proximity switch means, said direct current power source and said solenoid directional control valve means comprising an electrical network,

said electrical network further comprising electrical latching (i.e. self-holding) circuit means comprising said electrical relay assembly means, both said proximity switch means, said direct electrical series connection between said proximity switch means, said relay coil means, a pair of electrical contacts within said electrical relay assembly means, and interconnecting electrical wiring, the proximity of said magnetic piston means to said normally open proximity limit switch means acting to energize said relay assembly means and said relay coil means to thereby close said pair of electrical contacts of said electrical relay assembly means and complete a direct current circuit that remains closed and complete even after said piston commences reciprocation and leaves the proximity of said normally open proximity switch means to thereby cause said normally open proximity switch means to return to its normally open position, said direct current circuit remaining latched, closed and complete until such time as the further reciprocation of said piston brings said piston into the proximity of said normally closed proximity switch means to thereby open said last mentioned proximity switch means and open and deenergize said electrical latching circuit.

26. An improved control network for hydraulic drive cylinder means comprising:

a non-magnetic hydraulic drive cylinder tube containing magnetic piston means and piston shaft means slidingly mounted therein for linear reciprocation, said piston means dividing said tube into upper and lower chambers for alternately receiving hydraulic fluid to drive said piston means in first one direction and then the other direction to achieve reciprocation of said piston shaft,

one normally open proximity limit switch means having two electrical leads, said switch being located near one end of said non-magnetic cylinder tube,

one normally closed proximity limit switch means having two electrical leads, said last mentioned switch means being located near the other end of said non-magnetic cylinder tube,

one electrical lead of said normally open switch directly electrically series connected to one electrical lead of said normally closed switch,

electrical relay assembly means electrically connecting said series connected proximity switches and also electrically connected to solenoid directional control valve means and a direct current power source, said electrical relay assembly means comprising relay coil means to actuate throw switch assembly means to alternately energize and deenergize said solenoid directional control valve means responsive to alternating electrical signals from said proximity switch means,

said proximity limit switch means, said electrical relay assembly means, said direct electrical series connection between said proximity switch means, said direct current power source and said solenoid directional control valve means comprising an electrical network,

said solenoid valve means operable in a hydraulic network supplying hydraulic fluid from a variable volume pressure compensated hydraulic pump to a first chamber of said drive cylinder when said solenoid valve means is in a first position and to a second chamber of said drive cylinder when said solenoid valve means is in a second position,

and positive reciprocation means to eliminate stalling of the magnetic piston means in mid-stroke and to automatically return said magnetic piston means to an up-stroke position when said solenoid valve means and said electrical relay assembly means are deenergized, said positive reciprocation means comprising providing a single solenoid directional control valve assembly of the two position spring offset type as the solenoid valve means, said single solenoid directional control valve being biased in a normal, deenergized position when said electrical relay assembly means is also in a deenergized position, to provide hydraulic fluid flow through said solenoid valve means from said hydraulic pump to said lower chamber of said drive cylinder tube to thereby raise said magnetic piston means to the up-stroke position when said solenoid valve means and said relay assembly means are electrically deenergized.

27. A hydraulic drive cylinder assembly comprising top and bottom manifolds and a hydraulic cylinder tube mounted therebetween fabricated of non-magnetic material, said manifolds having hydraulic oil communication ports formed therein, a hydraulic piston within the said hydraulic cylinder tube comprising, at least in part, magnetic material;

upper and lower magnetic-responsive reed-type proximity limit switches positioned at either end of said cylinder and electrically responsive through combination electric network means and hydraulic network means to the presence of the magnetic material in the hydraulic piston to alternately activate solenoid valve means connected to hydraulic pressure generating means from a first position in which said solenoid valve means directs said hydraulic piston in one direction to a second solenoid valve means position in which said solenoid valve means directs said hydraulic piston in the other direction of a reciprocating cycle, said solenoid valve means having selectively communicating hydraulic oil passageways on the exterior surface thereof in matching alignment with selectively communicating hydraulic oil passageways formed in said top manifold, said solenoid valve means being mounted immediately juxtaposition to and integrally and contiguously with said top manifold by fastener means to provide selectively communicating hydraulic oil pathways between said top manifold and said solenoid valve means, thus ease of replacement is facilitated, interchangeability and serviceability are improved, and requirements for hard electrical wiring and hydraulic drive cylinder assembly component space requirements are reduced,

said electric network means comprising electrical relay assembly means and said upper and lower magnetic-responsive reed-type proximity limit switches, said electrical relay assembly means and said proximity limit switches being mounted within and below a smooth exterior surface of an electronic directional control board, said electronic directional control board being immediately mounted to said manifolds to form one integral and contiguous unit therewith, said mounting also placing said electronic directional control board immediately juxtaposition said hydraulic cylinder tube, whereby ease of replacement of said control board is facilitated, interchangeability and serviceability are improved, and requirements for hard electrical wiring and hydraulic drive cylinder assembly component space requirements are reduced.

28. Materials pumping means for pressurizing and spraying viscous liquid materials comprising:

a double acting piston pump comprising an upper pump housing mounting an upper plunger assembly for reciprocation therein and a lower pump housing mounting a combination lower plunger assembly and pumping head cage for reciprocation therein, a pump shaft connecting said upper plunger assembly to said pumping head cage and said lower plunger assembly,

said plunger assemblies and pump shaft being mounted for vertical reciprocation, both said plunger assemblies having seal means for moving in sealing engagement with inside housing surfaces of their respective pump housings, said upper pump housing being open to the outside atmosphere at an upper end thereof,

reciprocating drive means for reciprocatingly driving said pump shaft and said plunger assemblies,

control network means for controlling the reciprocation of said pump shaft and said plunger assemblies,

said control network means incorporating means for protecting the seal means of said upper plunger assembly from being damaged from contact with encrusted viscous material which may harden on the inside surface of said upper pump housing due to exposure to the atmosphere,

said means for protecting said seal means comprising means within said control network means for positively returning said pump shaft, said plunger assemblies, and said seal means to their uppermost vertical reciprocating positions responsive to deactuation of said control network means, said means for positively returning prohibiting said upper plunger assembly from coming to rest in another position and protecting the seal means of the upper plunger assembly.