Patent Application
20130255985
Embodiments relate generally to jackhammers, and, more particularly, to a portable jackhammer having an internal combustion engine.
Conventional jackhammers often work via expansion of compressed air in a cylinder. Thus, conventional jackhammers may require a source of compressed air.
A need may exist for a self-contained, portable jackhammer that does not require an external source of compressed air. Such a self-contained, portable jackhammer could be used in emergency situations where electricity may not be available and where it may be difficult to move an air compressor to a desired location to operate a jackhammer. Embodiments were conceived in light of the above-mentioned problems or limitations, among other things.
At least one embodiment includes a portable jackhammer system having an internal combustion engine to drive an impact piston, which contacts a chisel and allows the jackhammer to chisel material such as concrete, asphalt, rock, stone, or the like. The internal combustion engine can be constructed and adapted to operate on a fuel such as methane, butane, propane or the like.
The portable jackhammer system can include a fuel tank, an ignition system and a housing. The internal combustion engine can include a single piston that can be biased by a spring.
In operation, fuel is supplied to the engine from the fuel tank 112 via a fuel line in which the flow control valve 114 and check valve 115 are placed in-line. Air is introduced to the engine via one of the one-way check valves 124.
During an intake phase (shown in
During a compression phase (shown in
During an ignition phase (shown in
Once the piston 108 is in a lowered position (shown in
To start the jackhammer, the handle is used to move the piston to a lowered position and it is locked into place, the flow control valve on the fuel tank line is opened to allow gas (e.g., methane, propane, butane, or the like) to flow. The lock on the handle is released, which permits the piston to move upward under the influence of the bias spring, thereby creating a vacuum in the bottom portion of the chamber, which draws in air and fuel gas.
The process of moving the handle down and locking it and then releasing it can be repeated, thereby pumping the fuel/air mixture from the bottom chamber to the cylinder/piston opening. Then, the ignition system can be activated and a spark will ignite the fuel/air mixture resulting in an explosion causing the piston moves down which the lower part of the piston contacts the chisel. During this period a next portion of fuel/air mixture is drawn in and a cycle is formed and moves in the working chamber repeats. The engine of the jackhammer works similar to that of a two-stroke engine.
To stop the jackhammer, the ignition system can be switched off.
It will be appreciated that specific dimensions of an implementation of the jackhammer described herein can vary, but overall dimensions may be similar to that of conventional pneumatic jackhammers. For example, the cylinder volume (which can include the opening in the top of the piston) can be about 500 cubic centimeters, for example.
The piston can be made from aluminum, and in the lower part can include a steel insert where the piston strikes the chisel. The case, piston and springs can be made from steel.
For prevention of fire of the fuel/air mixture between the working and bottom chamber on the connecting fuel supply line also there is a one-way valve (two can be used, one at the beginning of the line and one at the other end so it can be more reliable).
While the invention has been described in conjunction with a number of embodiments, it is evident that many alternatives, modifications and variations would be or are apparent to those of ordinary skill in the applicable arts. Accordingly, Applicant intends to embrace all such alternatives, modifications, equivalents and variations that are within the spirit and scope of the invention.
