US 3552417 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
United States Patent 2,443,146 6/1948 Pules lnventor Casper M. Goff Comstock Township, Kalamazoo County, Mich. (Rte. 1, Box 246, Galesburg, Mich. 49053) Appl. No. 775,310
Filed Nov. 13, 1968 Patented Jan. 5, 1971 PUMP CONSTRUCTION 6 Claims, 7 Drawing Figs.
int. 605d 11/00 Field oiSearch 239/332,
References Cited UNITED STATES PATENTS 2,687,739 8/1954 Shelburne et al. 239/334 3,146,786 9/1964 lshikawa 103/42X 3,207,378 9/1965 Trumbull et a1. 313 334x 3.341.128 9/1967 Magin etal 1239-304X 3,411,673 11/1968 Mann .1. lO3/42X 3,433,240 3/1969 Lehmann 103/42X 3,474,965 10/ 1969 Coleman Primary ExaminerLloyd L. King Attorneywoodhams, Blanchard and Flynn ABSTRACT: Apparatus for controlling the pressure applied to a liquid which is supplied to a nozzle wherein the pressurized liquid is mixed with a pressurized gas. Valve means controls the pressure applied to the liquid, and a variable chamber means is arranged to actuate the valve means. The variable chamber means contains work means responsive to changes in pressure in the gas whereby to actuate the valve means and thereby reduce the pressure on the liquid.
not been entirely satisfactory.
,ru vii cons'rnu'crion FIELD or THE INVENTION This invention relates to a pump control structure and, 'rnore particularly, relates to valve structure for activating and f it 3,552,417
deactivating a pumpfor supplying viscous liquid to a nozzle,
wherein the viscous liquid is mixed with a gas, such as air, and 'wherein the operation of the valve structure is responsive to It has been standard practice to heat the asphalt-used which is combined with small, stones to covera surface, such as a roof. .ln most instances,- the asphalt is heated in a large container an then carried in buckets or the like to the surface where git is spread by some type of manually operated applicator. The asphalt is usually applied to sheet material, such as tar paper (sometimes referred to as roof felt) which isplaced over the roof boards or other sublayer of the roof structure. Apparatus has been devised which eliminates the need for heated asphalt which must be carried in' buckets to'the surface being worked upon,- and such apparatus is disclosed in the copending application of MyronsF. Goff, Ser. No. 650,794, filed July 3, l967. Moreover, it has been found that the cold asphalt material produces a Io'nger-Iastin'gand more weather control system being responsive to but independent of the pump for moving the highly viscous liquid.
Other objects of this invention ,will become apparent upon reading the descriptive material and examining the accompanying drawings, in which:
FIG, 1 is a schematic diagram of an apparatus including a pump embodying the invention.
FIG. 2 is a front view of the pumping device as used with a drum of liquid.
FIG. 3 is a broken side view of the pumping device as seen from the cutting line III-III in FIG. 2. I
FIG. 4 is a sectional view taken-along the line IV-IV in FIG. 3
I FIG. 5 is a sectional view similar to FIG. 4 but with the pump valves in different positions."
FIG. 6 is a side 'elevational vie view of the control valve mechanism and the control valve actuating unit.
FIG. 7 is a longitudinal sectional view of the valve actuating unitJ For convenience in description, the terms up," down," right and'left-.and words of similar import will have I reference to the corresponding parts of the apparatus as apresistant surface which is farless likely to leak than a hotasphalt roof. i v
Briefly, the cold asphalt. is pumped to a nozzle wherein the 'coldasphaltbecomes entrained in a stream of air'and thereby sprayed ontolthel surface being coveredf'llowever, many problems arose in the development-of a pump having sufficient power to. transfer the highly viscous, cold asphalt liquid .from the storagercontainer to the nozzle. Moreover, it was necessary to adequately and accuratelycontrollthe pump so that when the nozzle-was closed (by a control), the pressurizedviscou's asphalt liquid would notburst the conduits interconnecting the pump to the nozzle. While bursting could be avoided by heavy-duty conduits, such conduits severely restricted the area which could be covered, due to their weight and stiffness- 4 One of several attempts to solve the problem included the utilization of a pressure control bypass valve located in the length of the conduit between the pump and the nozzle is pearing in the respective figures of the drawings. The terms in, -out" and derivatives thereof will have reference to the geometric center of the device and designated parts thereof.
SUMMARY OF THE INVENTION The objects and purpose of the invention have been met by providing an apparatus capable of pumping a high volume of relatively cold and viscous liquid asphalt through a long con duit to a nozzle where it is mixed with pressurized air, the pressure of .which is utilized to control the power means driving the pumping mechanism. This system includes a lightweight, high-volume pump which has a reciprocating piston driven by hydraulic fluid. A bypass valve is provided in the hydraulic preferably at least 400 feet so that it can conveniently extend from a truck-up to a roof, ease of handling of the conduit is a necessity. However, the use of existing pump equipment has Various types of commercially available pumps were tried butthey-proved to be too heavy structurally and without adequately sensitive; pressure cutoff means. The viscousasphalt liquid is storedin portable containers such as SO-gallon drums. When one container becomes empty, it is necessat ry to transfer'the pumps from the empty container to a full ference of the pump between containers extremely difficult and time consuming Accordingly, his a primary object of this invention to provide a pump device which will move viscous liquid through a long conduit and willfrespond by reducing its force upon: the liquid, in response to an abnormal increase in pressure of the liquid generated at a considerable distance from the pump.
A further object of this invention has been the provision of a control system, analogous to a bypass valve, for dumping the highly viscous pressurized liquid-back into a reservoir, the
DETAILED DESCRIPTION In the following descriptive material, the diagram of FIG. 1 will be discussed in general and then followed by a discussion of the individual components of the diagram to the extent required to disclose the invention.
. The apparatus lo utilized for pressurizing a viscous asphalt liquid 11 and spraying same onto a surface of roof felt is comprised of a portable liquid container. 12 from which the liquid is removed by a liquid pump 13 and urged through the conduit 14 to aflow control 16 and thence to the'nozzle 17. The asphalt liquid may be mixed with other ingredients and such is normally contemplated.
Hydraulic fluid 18 is drawn from a tank 19 by a hydraulic pump 21 driven by a motor 22 whichsupplies the hydraulic fluid under pressure through the conduits 23 and 24 to the liquid pump 13. A bypass valve 26 in the hydraulic fluid line 27 diverts the flowof hydraulic fluid from the pump mechanism 13 to the tank 19. The valve 26 (FIGS. 1 and 6) has a first position 28 directing the flow of fluid from the conduit 23 into the conduit 24 and a second position 29 diverting the flow of hydraulic fluid from the conduit 24 into the line 2 and back to the tank 19. I
The valve 26 is actuated by a variable chamber device 31 (FIGS. 6 and 7) which consists of a cylinder 32 having a piston 33 slidably disposed within the chamber'39 and a rod 34 connecting the piston 33 with the valve element 35 in the bypass valve 26. A spring 40 normally biases the valve 26 and the piston 33 into the positions thereof illustrated in FIGS. 1 and 7. That is, the valve element assumes the position 28 which directs the flow of hydraulic fluid through the conduit 24.
Air is pressurized by a conventional component, such as a compressor, generally indicated at 37 and is supplied through the conduit 38 to the chamber 39 of the variable chamber device 31. The air is supplied to the flow control 16 and the nozzle 17 through the conduit 36. A passageway 41 of small cross section communicates through the walls of the cylinder 32 between the opposite sides of the piston 33, where it is in its normal position of FIG. 7, so as to equalize the pressure on the opposite sides of the piston.
The conduits 14 and 36 may be in the order of 400 feet long so that most of the apparatus can be located on the ground and the mixing valve or flow control 16 and nozzle 17 can be located with the operator on the roof ofa building. A pressure gauge 42 (FIG. 6) may be connected to the line 36 near the cylinder 32.
As illustrated in FIGS. 2 and 3, the pump 13 is secured to a frame 43 and is reciprocated by the piston 47 of the hydraulic cylinder 46. That is, hydraulic fluid 18 is alternately supplied to opposite ends of the cylinder 46. A finger 48 is secured to L the piston rod 47 by an annular clamp 49, and the finger 48 extends radially therefrom. A pair of spaced limit switches 51 and 52 are secured to the frame 43 and are disposed in the path of the finger 48. The limit switches 51 and 52 are either electrically or hydraulically connected to a conventional fourway valve 45 for directing the hydraulic fluid alternately to the opposite ends of the cylinder 46 whereby the direction of hydraulic fluid flow to the cylinder 46 is automatically and intermittently reversed.
A pump cylinder 53 is secured to the lower end of the frame 43 and has a coaxial piston rod 54 secured to the lower end of the piston rod 47. The external surface of the piston rod 54 and the internal surface 56 of the pump cylinder 53 define a pump chamber 57 having a volume such that a substantial amount of liquid will flow upwardly through said chamber 57 on the downward stroke of the piston 58 as well as on the upward stroke thereof.
The piston 58 is slidably mounted on a bolt 59 which is connected to the lower end of the piston rod 54. The piston 58 has a plurality of lengthwise passageways 61 to provide communication between the opposite sides of the piston when it is in its raised position of FIG. 4. The head portion 63 of the bolt 59 has a seal 64 thereon which closes the lower ends of the passageways 61 when the piston is in its lowered position of FIG. 5.
A ball check valve 66 is secured to the lower end of the pump cylinder 53, and the ball element 67 is movable into and out of a position wherein the opening 68 is completely blocked by the ball element 67 as illustrated in FIG. 4 to block the escape of asphalt when the piston 58 is moved toward the ball check.
Conventional packing 68 is provided around the piston rod 54 adjacent the upper end of the pump cylinder 53 to prevent the escape of viscous asphalt material around the extension member 54. The packing 69 is secured in place between a snap ring 71 and a packing gland 72.
The sideward nipple 73 adjacent the upper end of the pump cylinder 53 defines the outlet ofthe pump chamber 57 and it is connected to the conduit 14 to supply viscous liquid asphalt to the control 16 and nozzle 17.
The preferred embodiment of the valve 26 and the variable chamber device 31 is illustrated in FIG. 6. The valve 26 is secured to a frame member 76 by a plurality of bolts 77. The valve spring 36 encircles an extension of the rod 34 which is slidably received through a block 78 on the frame 76 spaced from the valve 26. The valve element 35 is connected to the rod 34 and is urged leftwardly (FIG. 6) by the spring 36, which is compressed when the valve element is moved rightwardly by a movement of the piston 33 from its broken line position to its solid line position of FIG. 7. I
The device 31 (FIG. 7) has a pair of end caps 82 and 83 secured to the ends of the cylinder 32 by a plurality of bolts 84. The passageway 41 is connected to the chamber 39 through ports 86 and 87 in the wall of the cylinder 32, said ports being axially spaced a distance slightly greater than the thickness of the piston 33, as illustrated in FIG. 7. The port 86 also communicates directly with the conduit 36 whereas the port 87 is spaced from the conduit 36 bythe length of passageway 41. The rod34, which is secured to the piston-33, extends through an opening 88 in the end cap '83 and is connected, as aforesaid, to the valve element 35, as illustrated in FIG. 6. An O-ring is providedbetween the periphery of the rod 34 and the wall defining the opening 88 to prevent the escape of air from the chamber 39 ,o n.t h e right side of the piston 33 when the piston is moved intothe po'sition illustrated in solid lines in FIG. 7. An O-ring 89 encircles the periphery of the piston 33 to provide a seal between the piston and the internal wall surface 90 of the cylinder 32. The O-ring 89 on the piston 33 remains between the ports 86 and 87 regardless of the position of the piston. There is a slight space between the peripheral wall of the piston 33 and the surface 90 of cylinder 32.
The size of the opening 86 is such that there is a substantial pressure drop as air flows from within the piston chamber 39, on the left side of piston 33, into the conduit 36. Such reduced pressure also appears on the right side ofrthe piston 33 due to the passageway 41 and opening 87. Thisreduction in pressure is such that it compensates for the pressure exerted by the compressed spring 40 while the control device 16 is opened to permit the flow of air through the conduit 36 and nozzle 17. However, when the device 16 is closed, the pressure: will quickly equalize on opposite sidesof the piston 33 thereby permitting the spring 40 to move the piston into its broken line position of FIG. 7 where it blocks the port 86. However, some seepage occurs between the piston 33-and the left end of the surface 90 so that the piston can move into the broken line position of FIG. 7. r
OPERATION i. i
The operation of the device embodying the invention wil'l be apparent to skilled persons from the foregoing description, but a summary thereof will be given hereinafter for convenience.
The pump 13 is set into a drum 12 so that the opening 68 at the bottom of the cylinder 53 is near the bottom of the drum which contains the viscous asphalt liquid 11 to be supplied through the device 16 and the conduit 14 to the nozzle 17. The piston rod 47 of the hydraulic cylinder 46 and the piston rod 54 of the pump 13, being interconnected, are reciprocated by the alternating flow of hydraulic fluid into, and then out of, the upper and lower ends of the cylinder 46. Accordingly, the piston 58 is in the pump cylinder 53 will be moved with the rod 54. When the piston 58 is moved upwardly (FIG. 5), the viscous asphalt liquid is drawn from the container 12 through the opening 68 past the ball element 67 into thepo rti'on of the chamber 57 below the piston 58, thereby filling same. Simultaneously, the asphalt liquid within the portion of the chamber 57 above the piston 58 will be moved through the nipple 73 and the conduit 14 to the nozzle 17. When the finger 48 actuates the switch 52, the direction of movement of the piston rods 47 and 54 will be reversed and the downward movement of the piston 58 will seat the ball element 67 against the upper edge of the opening 68, thereby trapping the asphalt liquid in the lower end of the chamber 57. Thus, since the valve 58 is slidably mounted on the bolt 59, the piston 58 will move upwardly on the bolt 59 so that the trapped liquid can move through the passageways 61 into the upper end of the chamber 57. However, since the cross-sectional area of the upper part of the chamber 57 is less than the cross-sectional area of the chamber 57 below the piston 58, due to the presence of the large piston rod 54, the asphalt liquid material will also be driven upwardly and out through the'opening 73 as the piston 58 moves downwardly.
When the finger 48 actuates the switch 51, due to downward movement of said rod 47, the direction of movement of the piston rods 47 and 54 will again be reversed so that the piston 58 again moves upwardly, whereby the piston 58 will slide downwardly to seal the lower ends of the passageways 61 and the ball check 67 will close whereby to continue the upward flow of liquid through the chamber 57. Thus, it will be seen that a continuous flow of asphalt liquid is supplied through the conduit 14 to the control,16 and nozzle 17 even though the piston 58 is reciprocated. I
Compressed air is supplied by the air compressor 37 to the control 16 andnozzle 17 through the conduit 38, the variable chamber 39 of the device 31 and the conduit 36. When the control 16 permits the free flow of air and asphalt liquid to the nozzle 17 the force created by the air pressure on the left side of piston 33 is greater than the combined force created by the air pressure and the spring on the right side of the piston 33. Thus, the valve 26 and piston 33 are held in the positions illustrated in H05. 1 and 7, wherein thevalve 26 directs the flow of hydraulic fluid into the conduit 24 andthenceto the pump 13. As a result, hydraulic fluid will alternately cause the piston rods 47 and S4 of the pump mechanism 13 to reciprocate in the manner described above.
However, when the flow control 16 is closed and stops the flow of pressurized air and asphalt liquid to the nozzle 16, the pressure increases in the conduits l4 and 36. The pressure increase in conduit 36 is promptly transferred through the passageway 41 and the'port 87 to the chamber 39 on the right side of the piston 33 (FIG. 7). The resultant, equalized pressure permits the spring 40 to move the piston 33 leftwardly, thereby shiftingthe valve element 35so'that it assumes position 29 (FIG. 1) wherein it diverts thehydraulic fluid to the line 27 and reservoir 19. The pump mechanism 13 is thereby short circuited so that no hydraulic fluid is supplied thereto to provide the pumping action of the piston 58 in the pump cylinder 53. Thus, the increasedpressure in theconduit 14 is relieved and the conduit l4becornes relaxed. The conduit 36 still has pressurized air therein, but since air is compressible and light in weight, it creates no serious problem with respect to the handling of. the conduit.
The response of the device 31 is prompt and sensitive so that the valve 26 is shifted quickly to short circuit the pump 13.- The response must be prompt because the pump l3:is so powerful that it could cause considerable damage if it continued to urge liquid into the conduit 14 after the control 16 is closed.
it has been found that the device 31 operates effectively, as desired, regardless of wide variations in the pressure of the air supplied to the device through the conduit 38. For example, the pressure may vary from 50 p.s.i. to 150 p.s.i. providing the various components are constructed to withstand l50 p.s.i. (which they can be) and the device 31 will perform without any adjustment to shift the valve 26, as discussed above, when the control device 16 is closed.
In this embodiment, the opening 86 is made small because the pressure of the air supply is higher than normally required at the nozzle 17. However, by enlarging the opening 86 and reducing the opening 87. or passageway 41', the same operating results could be achieved with the device 31 while providing an acceptable air pressure at the nozzle 17 from a supply of,
about the same pressure. This suggests that the openings 86 and .87 could be made adjustable-for a wider varietyof uses, if
Also, it will be seen that the switches 51 and 52 could be replaced by a single electric switch which is closed during one stroke of the rod 47 and openedduririg the reverse stroke.
Although a particular preferred embodiment of the invention has been disclosed above for illustrative purposes, it will be understood that variations or modifications thereof, which lie within the scope of the appended claims, are fully contemplated.
1. In a apparatus including hydraulic pump means for urging lating the flow of liquid and gas, the combination corn risin a source of hydraulic flur under pressure and thir con uit means connecting same to said pump means; valve means in said third conduit means for diverting the flow of hydraulic fluid to said pump means; and variable chamber means communicating with said second conduit means, said variable chamber means having movable wall means operably connected to said valve means' for operating same in response to a selected increase in the pressure within said second conduit means, whereby the pressure in said first conduit means is reduced. 2. The apparatus defined in claim 1, wherein said gas is air and said liquid includes cold asphalt.
3. The apparatus defined in claimll, wherein said pump means comprises first and second coaxial cylinders, first and second coaxial and interconnected piston rods, and first and second pistons respectively connected to said first and second rods within said first and second cylinders, respectively, one of said cylinders being connected to said third conduit means and the other cylinder being connected to said first conduit means whereby said one cylinder and its piston effect reciprocation of the other piston.
4. The apparatus defined in claim 3, wherein said variable chamber means comprises a third cylinder having a third piston slidably disposed therein and defining said movable wall, said source of gas being connected to said third cylinder on one side of said third piston and to said control, said third piston being connected to. said valve means and said third cylinder being connected to atmosphere on the other side of said third piston.
5. The apparatus defined in claim 4, wherein said third cylinder has means defining a passageway communicating wit the interior of said third cylinder at spaced points; and including resilient means urging said third piston to remain in a first position between said points, when said liquid is flowing substantially normally, the strength of said resilient means being such that a material increase in pressure of said gas will overpower said resilient means and move said third piston into a second position blocking said passageway at the point on said other side of said third piston.
6. Apparatus for controlling the pressure applied to an incompressible fluid supplied to a mixing chamber, wherein said incompressible fluid is mixed with a compressible fluid, comprising in combination:
first pressure-creating means pressurizing said compressible fluid and connected in fluid circuit with said mixing chamber for supplying compressible fluid thereto; second pressure-creating means pressurizing said incompressible fluid and connected in fluid circuit with said mixing chamber for supplying incompressible fluid thereto; 1
control means for regulating the flow of compressible and incompressible fluids from said first and second pressurecreating means to said mixing chamber;
valve means connected in fluid circuit with said second pressure-creating means for decreasing the pressure applied to said incompressible fluid by said second pressurecreating'means; and
variable chamber means communicating with said compressible fluid circuit, said variable chamber means having actuating means connected to said valve means for operating said valve means in response to a selected increase in the pressure of said gas, whereby the pressure applied to said incompressible fluid is decreased.