US2738777A - Operating and ignition device for an explosion-driven ramming hammer - Google Patents

Description

March 20, 1956 A. N. WAMPACH 2,738,777 OPERATING AND IGNITION DEVICE FOR AN EXPLOSION-DRIVEN RAMMING HAMMER Filed Feb. 7, 1951 INVENTOR. 09 6: Mac/ Mam mo mu g 6. sm'lfm,

United States Patent OPERATING IGNITION DEVICE FOR AN EXPLOSION-DRIVEN RAMMING HAMMER Aloyse Nicolas Wampach, Luxembourg, Luxembourg Application February 7, 1951, Serial No. 209,339

Claims priority, application Luxembourg February 15, 1950 7 Claims. (Cl. 123--7) This invention relates to portable explosion-driven ramming hammers and more particularly to a novel operating system therefor device for portable explosion-driven ramming hammers.

One of the objects of the'present invention is to provide a ramming hammer which may be manually actuated in a simple convenient manner for starting the ramming operation of the ramming hammer.

Another object of the present invention is to provide a ramming hammer with a structure which permits exhaust gases to flow from the combustion chamber after the piston of the ramming hammermoves past a predetermined point irrespective of the position which the piston takes after it passes this predetermined point.

Also, it is an object of the presentinvention to provide a ramming hammer capable of accomplishing the above objects and at the same time made up of simple, ruggedly constructed elements which are very reliable in operation.

With the above objects in view, the present invention mainly consists of a ramming apparatus which includes a cylinder having a top wall and being formed in a side wall portion with an exhaust port located distant from the top wall. A piston is slidably mounted in the cylinder for movement above and below this exhaust port, and this piston has a top face forming a combustion chamber with the top wall of the cylinder. A first spring means is operatively connected to said piston for urging the same toward said top wall. An exhaust valve means is mounted on said piston to provide communication between the interior parts of said cylinder located on opposite sides of said piston. The said exhaust valve means include a valve member which engages said top face of said piston in the closed position of said exhaust valve means and is spaced from said top face of said piston and located in said combustion chamber in the open position of said exhaust valve means. A second spring means is operatively connected to said valve member for urging the same to the open position thereof. An intake valve means communicates with said combustion chamber for admitting a combustible mixture thereto during movement of said piston away to said top wall, and means for manually moving said piston away from said top wall of said cylinder to draw a combustible mixture into said combustion chamber and for simultaneously manually moving said valve member to the closed position thereof, whereby, when the mixture in said combustion mixture is ignited, the pressure of the explosion will maintain said valve member in the closed position thereof, and whereby, after said exhaust port is located between said piston and top wall, the pressure of the explosion will be reduced, said first spring means will move said piston toward said top wall, and second spring means will move said valve member to the open position thereof to provide communication between said combustion chamber and exhaust port when said piston is located between said exhaust port and top wall of said cylinder.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Referring now to the drawing, the portable explosiondriven ramming hammer devised according to the present invention includes, two springs 2 housed within the hollow arms 6 of a U-shaped actuating member 20 which is fixedly positioned around the top end of cylinder 1. As shown in the drawing, only half of U-shaped member 20 is visible, the other half being broken away so as not to unduly encumber the drawing. Springs 2 are secured to the lower ends of the arms 6 of the U-shaped member 20 in any suitable way and are suspended from the hooks 4 which extend outwardly from the top wall 26 of cylinder 1.

The portions of arms 6 which are disposed adjacent to the side walls of cylinder 1 are longitudinally slotted permitting the said actuating member 20 to be slidably moved vertically with respect to hooks 4 which respectively extend freely through the slots of arms 6.

Horizontally disposed handles 8, extending outwardly from and fixed to arms 6 of actuating member 20, provide a means whereby member 20 is readily gripped by hand and thereafter depressed to actuate the ramming hammer. As may be seen in the drawing, a rod 19 is rigidly affixed at its top end to actuating member 20 centrally of the latter, said rod 19 extending axially into cylinder 1 slidably through top wall 26 thereof. As U-shaped member 20 is depressed by the operator, rod 19 will necessarily move downwardly within cylinder 1.

Advantages resulting from this construction are that the springs 2 may be of great length and are particularly easy to mount because it is only necessary to attach the top ends of the said springs to hooks 4 and to attach their bottom ends to the lower ends of arms 6 in any suitable way.

The device provides a further advantage in that the air expelled from the upper chamber 27 by the upward stroke of the piston 17 and the air contained therein during the downward stroke will be usefully employed in cooling the operating cylinder. Such an arrangement was impracticable heretofore because the two springs necessarily had to pass through the top wall of the cylinder.

An ignition magneto (not shown) is mounted upon the top wall 26 of the device for producing the spark to initiate combustion.

Conventional portable explosion-driven ramming hammers are provided with an auxiliary piston which expels the burnt combustion gases and at the same time sucks in the fresh combustion mixture. Such ramming-hammers accordingly require two pistons, namely an operating piston connected with the ramming-bar and a drive piston for sucking in the gas mixture and discharging the burnt gases.

The present invention comprises a ramming hammer in which all the necessary operations are obtained by a single piston, all need for an auxiliary piston being eliminated.

As shown in the drawing, the piston 17 is separated from both striker bar 18 and rod 19 connected the U- shaped member 20. The striker bar 18 is provided at its top with a spring-seating flange 21 against which the spring 22 for retracting the ram 23 is seated. The retracting stroke of the piston 17 is produced by a spring 24 housed in a bore 25 in the striker-bar 18. Spring 24 is of suflicient length to drive the piston 17 upwards until it abuts against top wall 26 thereby insuring that all the residual gases'ofcombustion'are discharged 'from the combustion chamber 27.

The intake stroke commences with piston 17 by reason of the downward movement-of U-shaped member 20 and rod '19, advancing until it abuts against the flange 21 and it is at this time that the gaseous mixture, introduced within the combustion chamber during downward movementof the piston, is ignited. As the piston 17 is moved downwardly the combustion mixture is sucked in through the intake valve 28 and duct 28a into the combustion chamber 27 through the tube 29.

An exhaust valve 30 is provided to permit combustion gases'to passthroug'h piston 17,'the said valve being'urged to itsopenposition by a spring 31 andbeing closed when pressed against its seating as soon as the piston abuts against top wall 26. This valve is held in closed position by the rod 19 throughout the intake stroke and until ignitionoccurs. Thereafter the explosion pressure retains the valve 30 upon'its seat. When the piston 17 clears exhaust aperture 32, the pressure upon valve 30 is diminished thereby permitting spring 31 toopen the said valve.

A second exhaust port 40, located beneath the abovementioncd exhaust port 32, is provided so that combustion gases beneathpiston 17 may escape through this additional port 40 when exhaust port 32 is covered by piston 17, or when exhaust port 32 is located between the piston and the top wall of the cylinder.

Gases in the combustion chamber 27, in addition to passing to the outeratmosphere through the valve 30 and exhaust ports 32 and 40, may pass to the outer atmosphere through a bore 37 formed in the rod 19, extending axially along the same'from the bottom end thereof, and having a bottom open end "in communication with the combustion chamber, and through a pair of lateral bores 38 formed in the rod 19,'having outer open ends, and comrnunicating with the upper end portion of the bore 37. Thus, whenever the bore 37 communicates with the combustion chamber and the bores 33 are located above the top wall 26 of cylinder 1 so that the bore 38 communicate with the outer atmosphere, the bores 37 and 38 will provide an additional passage from'the combustion chamber to the outer atmosphere.

From the foregoing description and the accompanying drawing the features and characteristics of the new arrangements for explosion-driven ramming hammers will be clearly apparent. However, it should remain understood that the arrangements described may be modified in practice as to their'details of construction without exceeding the scope of the present invention.

Having now particularly described my invention what I claim as new and desire to protect by Letters Patent is:

1. In a ramming'apparatus, in-combination, a cylinder having a top wall and beingformed in a side wall portion with an exhaust port located distant from said top wall; a piston slidably mounted in said cylinder for movement above and below said exhaust port andhaving a top face forming a combustion chamber with said top wall; first spring means operatively connected to said piston for urging the same toward said top wall; exhaust valve means mounted on said piston to provide communication between the interior parts of said cylinder located on opposite sides of said piston, said exhaust valve means including a valve member engaging said top face of said piston in the closed position of said exhaust valve means and being spaced from saidtop face of said piston and located in said combustion chamber in the open position of said exhaust valve means; second spring means operatively connected to said valve member for urging the same to the open position thereof; intake valve means communicating with said combustion chamber for admitting a combustible mixture thereto during movement of said piston away from said top wall; and manually operable means for manually moving said piston away from said top wall of said cylinder to draw a combustible mixture into said combustion chamber'an'd for simultaneously manually moving said valve member to the closed position thereof, whereby, when the mixture in said combustion chamber is ignited, the pressure of the explosion will maintain said valve member in the closed position thereof, and whereby, after said exhaust port is located between said piston and top wall, the pressure of the explosion will be reduced, said first spring means will move said piston toward said top wall, and second spring means will move said valve member to the open position thereof to provide communication between said combustion chamber and exhaust port when said piston is located between said exhaust port and top wall of said cylinder.

2. In a ramming apparatus as claimed in claim 1, said manually operable means comprising a rod extending slidably through said top wall and having a bottom free end portion located in said combustion chamber over said valve member to engage and move the latter against said top face of said piston to close said exhaust valve means and simultaneously move said piston away from said top well against the action of said first spring means.

3. Ina ramming apparatus as defined in claim 2, said bottom free end portion of said rod being formed with a substantially axial bore extending inwardly from the extremity of said bottom free end portion of said rod, and said 'rod being formed with a lateral bore communicating with said axial bore and being spaced from the extremity of said bottom free end portion of said rod so that when said lateral bore is located above said top wall the interior of said combustion chamber communicates with the outer atmosphere through said axial and lateral bores of said piston.

4. In a ramming apparatus as defined in claim 2, said manually operable means further including a substantially U-shaped member having opposite legs located on opposite sides of said cylinder, having a substantially central portion fixed to said rod adjacent the top end portion thereof, and a third spring means connected to said cylinder and U-shaped member for urging said substantially central portion thereof away from said top wall of said cylinder and away from said piston to urge said rod out of said cylinder.

5. In a ramming apparatus as defined in claim 1, said cylinder beingfor'med with atle'ast one additional exhaust port located more distant from said top wall than said first-mentioned exhaust port so that gases on the side of said piston opposite from said combustion chamber may escape through said additional exhaust port when said first-mentioned exhaust port is coveredby said piston or is located between the latter and said top wall of said cylinder.

6. In a ramming apparatus as-defined in claim 1, a striker shaftlocated in said cylinder on the side of said piston opposite from said combustion chamber to be engaged by said'piston.

7. In a ramming apparatus as defined in claim 6, said striker shaft being tubular and having a top open end, and said first spring means being located within said striker shaft to extend through said top open end thereof for'moving said piston toward said top wall of said cylinder.

References cited in the file of this patent UNITED STATES PATENTS 1,858,707 Haage et al. May 17, 1932 2,053,720 Huck Sept. 8, 1936 2,072,224 Seidl Mar. 2, 1937 2,123,563 Cresien July 12, 1938 2,396,627 Wohlmeyer Mar. 12, 1946 2,533,487 Maurer et al. Dec. 12, 1950 2,543,126 Philippovic Feb. 27, 1951

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