US3003150A

US3003150A - Explosively actuated stud driving tool

Info

Publication number: US3003150A
Application number: US781343A
Authority: US
Inventors: Ernest E Temple
Original assignee: Mine Safety Appliances Co
Current assignee: MSA Safety Inc
Priority date: 1958-12-18
Filing date: 1958-12-18
Publication date: 1961-10-10
Anticipated expiration: 1978-10-10

Description

Oct. 10, 1961 E. E. TEMPLE ExPLosIvELY ACTUATED STUD DRIVING '.rooL

Filed Dec. 18, 1958 Y MMM-Www This invention relates to tools for driving studs, and more particularly those designed for use under Water.

In the copending patent application of Robert Temple and Ernest E. Temple, Serial No. 664,517, tiled June l0, 1957, now U.S. Patent No. 2,910,701, granted November 3, 1959, for Explosively Actuated Stud Driving Tool, a tool is shown for driving a stud when an explosive cartridge is red. Attempts to use that tool under water for driving studs into submerged objects have proved unsuccessful, because the Water in the barrel oiers too much resistance to the movement of a stud, with the result that the stud does not strike an object with enough force to penetrate it in the intended manner.

It is among the objects of this invention to provide for such a tool a special barrel that will permit the tool to be used successfully under water.

In accordance with this invention, the barrel is provided near its rear end with piston and cartridge receiving areas located immediately behind a stud receiving area. A cartridge, stud and the intervening piston are inserted in these areas. The side of the barrel beside the rear end of the stud receiving area is provided with a bypass that is slightly longer than the piston. Consequently, when the cartridge is red and the expanding gases start to drive the piston and stud forward, some of those gases will pass the piston as it travels between the ends of the bypass. This escaping gas that ows around the piston will force the Water out of the barrel ahead of the piston so that the water will not retard the stud.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which:

FIG. 1 is a side view of the tool ready for use;

FIG. 2 is an enlarged longitudinal section taken on the line II-II of FIG. l;

FIG. 3 is an end view of themuzzle end of the tool; and

FIG. 4 is a fragmentary cross section of the barrel through the front ends of the bypasses.

Referring to the drawings, the tool may have a cuplike stock 1 joined to the front end of a handle 2 that is oset laterally from the axis of the stock. Rigidly mounted in the stock is the solid rear end of a hollow cylindrical housing 3 that is open at its front end. Slidably and rotatably mounted in the housing is a plunger 4 that normally may project a short distance from the front end of the housing and has its rear end spaced from the back ofthe housing. 'I'he front end portion of the plunger is reduced in diameter to provide a radial shoulder 6 a short distance behind the front end of the housing. Forward movement of the plunger in the housing is limited by this shoulder engaging a coupling ring 7 that is screwed into the housing and that projects a short distance in front of it. The ring may be encircled by an integral flange 8 that engages the front end of the housing.

At one side of its axis, the plunger is provided with a passage 10 that extends lengthwise through it. At the opposite side of its axis, the plunger is provided with a bore 11 extending inward from its front end. A bushing 12 is screwed into the front end of this bore. A stud 13, with a head 14 on its rear end, extends Slidably through the bushing and has its front end screwed into a ring 15 that engages the front end of the coupling ring. The

ring 15 is eccentric because it has an opening 17 through 'neet essere@ Patented Oct. 10, 1961 it in axial alignment with passage 10 through the plunger. The stud is encircled by a coil spring 18 compressed be# tween its head and bushing 12, whereby the eccentric ring is held against the coupling ring, and the plunger is urged forward so that its shoulder 6 will be in contact with the coupling ring. The eccentric ring 15 is locked in the rear end portion of a tube 19 by means of screws 20 that extend through the wall of the tube and into the ring as shown in FIG. 2. The tube also encircles the coupling ring and is rotatable on it. The passage through the tube is ol center and is aligned with the passage through the plunger.

Extending through the plunger and tube 19 and projecting from the front end of the latter is a barrel, which preferably consists of a tube 22 encircled at its rear end by a sleeve 23. To provide positive support for a greater length of the barrel, asupporting sleeve 26 may be screwed into the front end of the plunger passage and extend forward through the eccentric ring opening 17. Since the barrel is Slidably mounted in the plunger and sleeve, it is normally retained in them by a split spring ring 27 mounted in a peripheral groove of the barrel and expanded into a similar groove inside the sleeve. Rearward movement of the barrel in the plunger is also limited by engagement of a shoulder 28, integral with the barrel, with the front end of the sleeve. The rear end of the barrel has a short area that receives a cartridge 30 that supports a stud 31 through an intervening piston 32 that ts the inside of the barrel.

When the parts are in the position shown in FIGS. 2 and 4 of the above-mentioned copending application, the rear end of the barrel is located beside a lateral opening 33 in housing 3 so that the cartridge receiving area is readily accessible from the side of the tool. The solid rear part of the housing and the stock are also cut away to provide room for lining up a stud and cartridge with the barrel so that they can be inserted in it. The plunger 4 cannot be moved axially in the housing when they are in that position, because such movement is prevented by a cap screw 34 extending through the side of the housing and into an annular groove 35 encircling the plunger.

. However, after the plunger has been rotated 180 to the tiring position shown in the present application, a longitudinal slot 36 in the outside of the plunger is lined up with the cap screw. As the slot extends forward, the housing can be moved forward on the plunger or, conversely, the plunger can be moved backward in the housing. The plunger was rotated by turning tube 19 relative to the housing, because the tube and plunger are connected through eccentric ring 15 and sleeve 26 and the barrel, and also through stud 13 and bushing 12. Rotation of the barrel in opposite directions is limited by a pair of stop pins (not shown) projecting radially from the plunger into annular groove 35. One or the other of these pins will strike the cap screw 34 and stop rotation of the plunger after it has turned l This tool may be provided with a special breecliblock that is in the form of a heavy metal plate 40 located in housing 3 behind the plunger and spaced from it. The breechblock is cut away at one side so that it will not cover Vthe rear end of the barrel in loading position. The rest of the breechblock is integrally joined with a ring 41 that encircles the plunger and that is screw-threaded'onto it. The rear portion of lthe ring is provided with a longitudinal slot 42 that receives the inner end of a pin 43 extending through the side of the housing so that the breechblock can move lengthwise of the housing without rotating in it. The screw threads are so arranged that when the barrel is swung from loading position around to a point 180 away, as shown in FIG. 2, the breechblock will be rdrawn forward toward the plunger to hold a cartridge securely in the barrel. The breechblock ring is provided with a radial opening 44 for receiving part of a spring-pressed ball 45 when the plunger is in firing position. The ball projects from the radial bore 46 in the side of the plunger.

The tool may also be provided with fa cartridge extractor, which preferably is a bar 5,0 that extends across the rear end of the plunger in .front of the breechblock. The bar has its opposite ends joined to a ring 53'that is slidably and rotatably mounted on the plunger inside :the breechblock ring. A split ring 54 in the breechblock ring engages the front end of the extractor ring to hold the extractor bar against the breechblock behind it. Consequently, the extractor has to move back and forth with the breechblock, so that when the latter is moved away from the plunger when the plunger is turned, the extractor will pull the cartridge part way out of the chamber.

In order to fire the cartridge after .the barrel has been swung into the tiring position shown, a n'ng Apinis mounted in the solid rear end portion of housing 3. The tiring pin consists of a point 62 projecting from the front end of a cylindrical body 63 Vthat is slidably mounted in a forwardly extending bore 64 in the back of the housing. The point normally extends through a small opening 65 that connects the front end of the bore with the open space behind the breechblock. This opening is in axial alignment with the barrel. A coil spring 66 is compressed between the firing pin body and the back of the stock to urge the pin forward. The point of the ring pin is long enough to also project through a hole 67 through the breechblock when the block is in engagement with the back wall of the housing, as it is when the head of the barrel is pressed against a stationary object and then the housing is pushed forward on the plunger.

The way the tiring pin is retracted against the resistance of spring 66, and then is released by a trigger 76 slidably mounted in a slot 77 in the handle, forms no part of this invention and will not be described. Reference can be made to said copending application if details are desired.

This tool may be provided with a shield to protect the operator. The shield encircles the barrel head and is rigidly mounted on the front end of a sleeve 96 rotatably mounted in tube 19 and fitting around part of the barrel. The rear end of the sleeve is provided with an annular groove 97, into which projects a plug 98 disposed .in a radial hole in the tube. The sleeve can be rotated so that the at edge of the shield can be located in any desired position relative to the handle of the tool, but the plug prevents the sleeve from being removed from the tube. The shield is held in any position by a spring 99 compressed between it and the front of the tube. To prevent removal of the plug, a headed pin extends lengthwise through the wall of the tube from eccentric ling and through the plug.

To summarize the operation of the tool disclosed herein, a combined cartridge and stud are inserted in the rear end of the barrel while it is exposed beside housing opening 33. Then the tube 19 is rotated a half turn to rotate the plunger. As the barrel is carried around 180 by the plunger, the breechblock moves forward against the rear end of the cartridge and clamps it in place as shown. The head of the barrel is then placed against the object that is to receive the stud, and the handle is pushed forward to move the back wall of the housing 3 against the breechblock. This movement simultaneously cocks the firing pin, so that upon squeezing the trigger, the tool will be tired and the stud will be driven through the barrel and into the object in front of it. Rotation of the plunger in the opposite direction exposes the spent cartridge, which is pulled part way out of the cartridge chamber by the .extractor 56. It is then an easy matter to remove the cartridge and insert a new cartridge and stud.

Although the tool as described this far can be used in the same way as the one disclosed in the above-mentioned copending patent application, it is a feature of the present tool that it also can be used satisfactorily under water. This is because the barrel is =so constructed that it will be emptied of water at the lmoment the cartridge is red, so that the stud Will `travel through gas instead Yof water on the way to its target. By eliminating the resistance of water to travel of the stud, the stud will be driven into an object with as much force as if the tool were operated in air. To accomplish this result, the side of the barrel beside the rear end of the stud is provided with a bypass that is slightly longer than Vthe piston. Expressed inV another way, the rear end of the stud receiving area of the barrel has a bypass that is slightly longer than the piston receiving area of the barrel directly in vfront of the cartridge receiving area. Such a bypass is provided by forming .a passage in the side wall of the barrel, extending from about the front end of the piston receiving area to apoint forward of the rear end of the stud receiving area. The distance between the two ends of the passage is a little greater than the length of the piston, so that as the pistou moves forward there will be a movement when it will be located between the opposite ends of the gpassage. At that moment, expanding gases behind the piston can flow through the passage and out -of its front end in front of the piston.

A preferred way of making the bypass is to reduce the diameter of the rear end portion of the barrel tube 22 and drill two longitudinally spaced holes radially through the side of the reduced portion to form the opposite ends of the bypass. The outside of the reduced portion of the tube then is provided with a longitudinal groove 1-11 that connects the two holes. Two or more grooves and pairs of holes can be Vformed this way to provide a multiplicity of bypasses. Two bypasses are shown in the drawings. After the holes and grooves have been formed, a sleeve 23 is fitted around the reduced portion of the tube to lforrn a passage between the front and rear holes. The opposite ends of the sleeve may be soldered to the tube.

When the cartridge 3i) is fired, the explosion drives the piston 32 and stud 31 forward in the barrel. The moment Athe piston passes the rear end of the `bypass and uncovers its rear opening, some ofthe expanding gases ow through the bypass and out of its `front end in front of the piston. Although the piston immediately thereafter passes beyond the bypass, the bypassed gases are sufiicient to blow `the water out of the barrel ahead of the piston. The front end 'or head of the barrel is provided with radial slots 109 that permit the water to escape from the barrel while it is pressed against the object into which the stud is to be driven. It will be seen .that at almost the instant the cartridge is red, the water in the barrel is blown out -of it by the pistonbypassing gases so that forward movement of the stud will not be opposed by the resistance of that water. The stud can therefore 'be driven with the necessary force into the object at the head of the barrel.

Another feature of this invention resides in the connection between the piston 32 and the cartridge. The customary way of attaching such a piston to a cartridge is to have a rearwardly flaring plug projecting from the rear end of the piston into the cartridge. The front end of the cartridge is crimped around the plug to hold them together. With my improvement, the plug 113 is provided with a circumferential groove 11-'4 in which a resilient vO-ring 115 is mounted. The ring normally projects slightly .from the groove so that kit has to be compressed when the plug is forced into the front end of the cartridge. This forms a tight seal between the plug and cartridge and holds them securely together, whether or not the cartridge is crimped around the plug. Also, the seal provided by the O-ring eiectively prevents 5 Water from entering the cartridge and moistening the powder in it.

According to the provisions of the patent statutes, I have explained the principle of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire -to have it understood that, within the scope of the appended claim, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

A barrel for a tool that will drive a stud under water by the ring of an explosive charge behind a piston at the rear end of the stud, the barrel being provided near its rear end with a piston and cartridge receiving area immediately behind a stud receiving area, and the side of the barrel being provided with a bypass having a rear inlet at the front end of said piston receiving area and References Cited in the le of this patent UNTTED STATES PATENTS Temple et a1. Dec. 23, 1952 Broughton et al Dec. 11, 1956 Maier Mar. 17, 1959