US2734488A

US2734488A - Portable internal-combustion

Info

Publication number: US2734488A
Authority: US
Publication date: 1956-02-14
Anticipated expiration: 1973-02-14

Description

Feb. 14, 1956 A. N. WAMPACH PORTABLE INTERNAL-COMBUSTION PERCUSSIVE TOOLS Filed Oct. 7, 1952 INVENTOR. A\ mp: Nmehua wameqgk BY." M g s. um

United States Patent PORTABLE INTERNAL-COMBUSTION PERCUSSIVE TOOLS Aloyse Nicolas Wampach, Luxemburg, Luxemburg Application October 7, 1952, Serial No. 313,420

Claims priority, application Luxemburg October 12, 1951 1 Claim. (Cl. 123-7) This invention relates to portable internal combustion percussive tools and it has for its object a percussive tool of this type which is an improvement on the type in present use and is adapted for use not only as a concretebreaker, a ram or like tool, but also as a rock-drill.

In portable internal combustion tools (concrete-breaking hammers, rams, rock-drills and the like) the return of the working piston gives rise to difliculties. Up to now, this return was due to the action of either compressed air or of exhaust gas, alone or mixed with air constituting a cushion, or again, most often, by springs in compression, of more or less length, acting underneath the working piston.

This latter solution of the problem, although apparently quite simple, has nevertheless the great disadvantage that these compression springs do not resist in the course of time the continual fatigue due to nearly 2000 strokes per minute with such a relatively long piston stroke, so that the springs lose promptly their resilience and fractures take place. According to my present invention, I provide a portable internal combustion percussive tool adapted to serve as a concrete breaker, a ram, or the like and also as a rock-drill, characterised in that the return of the working piston is caused by a tension spring housed in a steel tube disposed above the piston.

Referring to the accompanying drawing, which represents a preferred embodiment of the invention, given in the way of example:

Fig. 1 is a sectional elevation;

Fig. 2 is a plan view;

Fig. 3 is a sectional elevational of an alternative detail.

In the drawing, 1 is the working piston, the return of which takes place by means of a tension spring 2, housed in a tube 3, where it is sheltered from the heat of the explosion gases. The tube 3 is firmly held in a blind bore axially of the piston; it passes through the combustion chamber 4 and through the head 5' of the cylinder 5, providing with a fluid-tight stufiing gland 6.

In accordance with the invention, the tube 3 is tightly held in the bore of the piston 1 in which it is secured by a pin 7 to which is anchored one end of the traction spring 2. One end of this pin is provided with a projection 8 adapted to engage a longitudinal groove in the cylinder 5 so as to prevent any rotation of the piston. This arrangement does not only ensure a solid connection between the tube 3 and the piston, but it also allows the use of a tension spring 2 as long as may be necessary to practically eliminate any risk of rupture. This spring is anchored at the top to a cover 14 resting on the guiding rods 11.

2,734,488 Patented Feb. 14, 1956 The tube 3 serves at the same time as a pushing member for starting. With its help, the piston 1 is initially moved for starting the tool, in a simple and handy manner by the two handles 9, connected to a middle member 10 housed in such a way that it slides between the guiding rods 11. This middle member 10 is connected either to the tube 3, to be put in motion, by means of the claws 12, or else to the head 5 of the cylinder by means of the crank levers 13, if it is desired to cause the tool to work continuously once the piston 1 has been started.

It is advantageous to arrange the suspension of the spring 2 to the cover 14 so that it is adjustable, for example by a threaded member 33 (Fig. 3), so as to be able to give an optimum tension to this spring. It is then possible to suitably control both the compression of the gaseous mixture and the energy of impact of the strokes. V

In order to utilize the tool for work involving rockdrilling and the like, it is required to impart to the cutter a rotary motion at each stroke of the percussive tool, the cutter acting then as a drill. To this end, a rotary device is provided, adapted to automatically rotate the drill and blowing the dust produced by the cutter while the work proceeds.

According to the invention, a guiding rotative sleeve 15, carries the drill, which is preferably of hexagonal steel with a bore 17 throughout its length. This sleeve 15 is connected by notches 19 to another sleeve 18, provided on its periphery with teeth 20 (Fig. 2) constituting a ratchet wheel engaged by a pawl 21 acted by the tension spring 210. This pawl is housed in the body 22, one of the front faces of which communicates with the combustion chamber by means of the passage 23, while the other is controlled by the spring 24.

With such an arrangement, the explosion in the chamber 4 has also an elfect on the piston 22 and thrusts it forward, compressing the spring 24; the toothed sleeve 18 (Fig. 1) rotates through an angle corresponding to one tooth 20, and with it the sleeve 15 and consequently the drill 16. When the burnt gases escape at the end of a power stroke, the piston 22 is also unloaded and the spring 24 brings it back in the position shown in the Fig. 2.

The tool effecting about 2000 strokes per minute, and the ratchet wheel having about 20 teeth, the drill will make about turns per minute. The regulating stop 34 allows the length of the stroke of the piston 22 to be adjusted, and consequently also the speed of the angular displacement of the drill.

In accordance with the invention, the blowing air enters the device by the opening 25. It passes along the bore 26 which is controlled by the distributor 27 which is maintained by the spring 28 in the position shown in Fig. 2, closing the passage 26. It is only when the surface of the upper face of the distributor 27 has just been subjected to the pressure caused by the explosion in the chamber 4, exerted through the vertical bores 23 and the communication passage 29, that the distributor 27 is pushed downwards and an annular recessed portion 30 thereon opens the passage 26. The blowing air then passes from the inlet orifice through the passage 26 in the annular recess 31 and thence by the

bores

32 and 17 on the bottom of the hole being bored where it cleans the cutting edge of the drill 16. According to the invention, the blowing takes place therefore by gusts at each stroke. A needle valve 35 regulates the section of the passage 26.

What I claim is: t

In a portable internal combustion percussive device having an operating tool, in combination, an elongated housing member defining a lower cylinder chamber and an upper combustion chamber; piston means arranged reciprocably in said housing member with said lower cylinder chamber located under and said upper combustion chamber located above said piston means, said piston means serving for actuating the operating tool; tubular means located above and secured to said piston means; and resilient means in said tubular means and connected to said piston means permanently urging said piston 5 means toward said combustion chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,755,361 Pfluger et al Apr. 22, 1930 2,125,013 Charles July 26, 1938 2,225,531 Charles Dec. 17, 1940