US3672575A

US3672575A - Hydro blast saf-t-gun

Info

Publication number: US3672575A
Authority: US
Inventors: Jack F Hinrichs
Original assignee: Hydro Services Inc
Current assignee: Hydro Services Inc
Priority date: 1971-02-01
Filing date: 1971-02-01
Publication date: 1972-06-27
Anticipated expiration: 1989-06-27

Abstract

A high pressure water gun has a main conduit through which the high pressure water is directed which ends in a restricted nozzle for increasing the velocity of the water exiting therefrom. A cross-channel connects the main water conduit and a water dumping conduit which has a relatively low pressure outlet. The crosschannel has a floating valve positioned therein which is actuable between a seated and unseated position in a response to the movement of a pin valve. In turn, the pin valve is moved by a pivotably mounted lever under the influence of a force supplied by the cam surface of the handle lever.

Description

United States Patent Hinrichs 1451 June 27,1972

3,599,876 8/1971 Kyburg ..239/498 X Primary Examiner-M. Henson Wood, Jr. Assistant Examiner-Michael Y. Mar

Attorney-Cushman, Darby & Cushman 57 ABSTRACT A high pressure water gun has a main conduit through which the high pressure water is directed which ends in a restricted nozzle for increasing the velocity of the water exiting therefrom. A cross-channel connects the main water conduit and a water dumping conduit which has a relatively low pressure outlet. The cross-channel has a floating valve positioned therein which is actuable between a seated and unseated position in a response to the movement of a pin valve. In turn, the pin valve is moved by a pivotably mounted lever under the influence of a force supplied by the cam surface of the handle lever.

5 Claims, 2 Drawing Figures 1521 u.s.c1 ..239/445,239l447,239/581, 137/332 51 1111.01 ..'...nosb 15/00 581 FieldoISearch ..239/443,444,445,447,581; l37/332,331,561,609,610

[56] References Cited UNITED STATES PATENTS 2,342,050 2/1944 Hurst .239/104 3,369,755 2/1968 Rodenetal ..239/126 F PI P'A'TEHTEDJUHN 1972 I INVENTOR din/ 1. M/VF/ 6 35 1 n mu. m g 1 iii 1.

1 nvnno BLAST SAF-T-GUN BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to high pressure water blasting guns and, more particularly, to safety devices whereby an operator holding a high pressure water blasting gun may quickly reduce the velocity of the water issuing from this gun.

2. Description of the Prior Art While high pressure water blasting guns have longbeen known as efiicient cleaning and shaping tools they have the built-in disadvantage of danger. Water issues from the typical high pressure water blasting gun at a speed of approximately 800 feet per second. It should be obvious that even a relatively small volume of water traveling at such a speed is capable of transferring tremendous momentum and is, therefore, extremely dangerous to human beings positioned within a short range of the gun. It is, therefore, necessary for the operator of a high pressure water blasting gun to be able to quickly reduce the velocity of water issuing therefrom. The prior art developed a system whereby a channel parallel to the main water channel was provided and a cross-channel connected the main water channel to the safety channel. A valve was located in the cross-channel that was actuated by a handle lever. In operation a high pressure water blasting gun having a safety device, which is called a dump gun in the art and shall be so called hereinafter in this application, requires the operator to grip the handle lever which, in turn, seats the valve in the cross-channel and thus cuts off the water safety dumping channel from the main channel. Of course, when the operator releases the handle, the cross-channel valve is unseated and the high pressure water chooses the low pressure outlet in preference to the high pressure nozzle, thus quickly reducing the high velocity output from the main channel.

The dump guns known to the prior art, however, suffer from at least two major disadvantages. First, because of the great pressure involved, the mechanical force required to depress the handle lever is so great that it makes the depression of this lever tiresome and, therefore, reduces the operating time of the nozzle.

Secondly, also because of the high pressures involved the dump guns known to the prior art commence leaking after a few hours in service. Since high pressure water blasting is a low water volume technique, excessive leakage affects the output volume and the output pressure from the dump gun.

SUMMARY OF THE INVENTION In view of the disadvantages discussed above, it is one object of the applicant's invention to provide a dump gun which requires only moderate force for depressing the handle. It is a further object of the applicant's invention to provide a dump gun which is less prone to leakage than the dump guns known to the prior art.

Basically, the applicants invention comprises a dump gun, which has a main channel with a high pressure water blasting nozzle connected at its output, a water dumping channel with a relatively low pressure output end and a cross-channel for connecting the main channel and the water dumping channel in parallel. Within the cross-channel a floating valve is located which has a cylindrical bore stopped by a pin valve. When the pin valve is removed from the cylindrical bore, the floating valve is urged by the high pressure water acting upon a shoulder of the floating valve into an open position and the high pressure water exits through the relatively low pressure outlet from the water dumping channel in preference to the high pressure, high velocity nozzle of the main channel. While the floating valve is floating it is also rotating due to the interaction of the water passing through its cross-channels and the knurled shoulder on the valve. Thus, the valve is never seated in the same position twice which promotes self-lapping of the valve-valve seat interfaces. The pin valve is held against the floating valve by means pivoted lever and force is applied to the other end of the pivoted lever through a cam portion of the pivotably mounted handle lever which acts as an efficient force multiplying means.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a side view of a dump gun in accord with applicant's invention partially in section.

FIG. 2 is a cross section of a portion of the dump gun shown in FIG. 1 taken substantially along the line 2-2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawing reference numeral 1 indicates generally the dump gun in accordance with applicants invention while numeral 2 indicates the high pressure water inlet to the dump gun. The high pressure water passes through the body 3 of the dump gun within the main channel 4 and exits through high velocity water blasting noule 5. Since the blasting nozzle 5 serves to increase the velocity of the high pressure water within the main channel 4, it also presents to the main channel 4 a highly restricted outlet.

Branching from the main channel 4 within the dump gun body 3 is a cross-channel 6 in which a floating valve 7 seats against the main valve seat 12. The floating valve contains a central coaxial bore 9, and has a knurled shoulder 8 best seen in FIG. 2 and a pin valve seat 10 which accepts the pin valve 11. When the pin valve 11 mates with the pin valve seat 10 the floating valve is forced towards the main valve seat 12 to close the water dumping channel 13.

The water dumping channel 13 communicates with a low pressure outlet generally indicated at 14 which includes a series of orifices 15 circumferentially disposed about the water dumping channel 13 at its downstream end. Surrounding the orifices 15 is the safety shield 16 which protects the operator and other nearby personnel from the direct effect of the water exiting therethrough. Because there are 16 orifices located at the low pressure outlet 14, and none of these orifices is a converging type nozzle, the low pressure outlet presents a much lower obstacle to the exiting water than does the blasting nozzle 5.

The pin valve 11 is held against the valve seat 10 under the action of lever 17, which is pivotably rotated about point 18 by force applied to the end of lever 17 opposite the pin valve by the cam 19 which forms a portion of the handle lever 20.

The handle lever 20 is mounted on pivot 21 to move pivotably with respect to the body 3 of the dump gun and the handle 21 which extends from body 3 of the dump gun. Handle 22 forms with the handle lever 20 an efficient grip whereby constant pressure may be applied to lever 17 and thereby to the pin valve 11.

When the handle lever 20 is squeezed against handle 22 in an operators hand the handle lever 20 pivots about pivot point 21 and the cam surface 23 on handle lever 20 is rotated into portion 24 of lever 17. Because the distance X between the point P at which the cam surface 23 and portion 24 contact is much closer to the pivot point 21 than is the distance X from the pivot point to the point P where the operator's hand exerts force to squeeze the handle, the force exerted at point P is multiplied by the ratio X'IX with respect to the force exerted at point P. Similarly, since the distance Y between the point P and the pivot point 18 is greater than the distance Y between the point P" where the lever 17 contacts the pin valve 11, and the pivot point 18, the force exerted at point P is multiplied by the ratio Y/Y' as it is applied to pin 11. Because of this compound cam-lever action the ratio of closing force acting upon the pin valve 11 to the handle lever actuating force F, in one operative embodiment is approximately 224 to l. This is a great improvement over the prior art in which the handle lever was the valve actuating means and developed a total mechanical advantage of approximately 20 to l.

The second major improvement of the invention uses the fact that valve 7 is a floating valve, i.e., it is not restrained from inter alia rotation about its axis. This improvement comprises the knurling of shoulder 8 of the floating valve 7 which causes the floating valve to be rotated about its axis by water passing through cross-channel 6 to the dumping channel 13. This means that the floating valve 7 never seats in exactly the same position with respect to the pin valve 11 or the main valve seat 12. In other words, instead of producing uneven wear in either the pin valve or the main valve seat the rotating floating valve 7 actually polishes these seating surfaces and thus prevents leakage. in addition, the rotation of the floating valve prohibits uneven wear upon the upper surface of the main valve seat 12 which is exposed to the force of the water issuing from crosschannel 6. I

While the above describes the preferred embodiment of applicants invention, it should be obvious to one skilled in the art that many modifications may be made to the preferred embodiment within the scope of applicant's invention. Thus, for example, the shoulder 8 may be grooved with spirals or small blades may be mounted thereupon, to produce rotation of the floating valve.

What is claimed is:

1. In a safety release for a high pressure water gun having a high pressure main water channel with a high pressure, high velocity blasting nozzle at the end, a water dumping channel with a low pressure outlet, a cross-channel connecting said main channel to said water dumping channel, a valve means disposed in said cross-channel having an open and a closed position for controlling the flow therethrough, a handle lever actuable by an operator to actuate said valve means and open the cross-channel, the improvement comprising that said valve means is a floating valve having means for rotating said valve means about its axis when the valve means is in its open position and thus under the influence of water issuing from the cross channel.

2. The safety release as claimed in claim 1 wherein said floating valve has a shoulder and said rotating means comprises a knurled pattern upon the shoulder.

3. The safety release as claimed in claim 1 further including means actuable by said handle lever for amplifying the force applied to said handle lever by a factor of at least and applying this force to urge said floating valve means to its closed position.

4. The safety release as claimed in claim 3 wherein said actuable means includes a pivotally mounted lever which contacts said pin valve at its first end portion and cam means on said handle lever for engaging said pivotally mounted lever in point contact near its second end portion, wherein the handle lever and pivotally mounted lever are so dimensioned that a force applied to the gripping portion of said handle lever is amplified and transferred by said cam means to said pivotally mounted lever and by said pivotally mounted lever to said pin with a total force amplification of at least 100 times.

5. A high pressure water gun having a high pressure main channel with a high pressure, high velocity blasting nozzle at the end, a water dumping channel with a low pressure outlet, a cross-channel connecting said main channel to said water dumping channel, a floating valve means disposed within said cross-channel having an open and a closed position for controlling the flow therethrough, means for rotating said valve means about its axis when said valve means is in its open position and, thus, under the influence of water issuing from said cross channel, a handle lever actuable by an operator and means actuable by said handle lever for amplifying the force applied to said handle lever by a factor of at least 100 and applying this force to urge said floating valve means to its closed position.

Claims

3. The safety release as claimed in claim 1 further including means actuable by said handle lever for amplifying the force applied to said handle lever by a factor of at least 100 and applying this force to urge said floating valve means to its closed position.