You are looking at the world's first and only vibrationless and noiseless jackhammer ... a dream come true for anyone who operates a jackhammer. By efficiently distributing almost all of the compressed air into the business end of the breaker, this revolutionary jackhammer can produce more work at higher speed with less wear and tear on the operator. There is such minimal vibration, you can balance on a quarter on it while breaking concrete! Less vibration means longer part life and less metal fatigue failures, not to mention more productive work time from workers. And, with half the moving parts of conventional jackhammers and a smaller air compressor, the Gentle Jack can save thousands of dollars per year in operating and maintenance costs. Less stress, less noise, less money! And if all of that wasn't enough, the Gentle Jack costs less to buy.

The Gentle Jack \Actually eliminates wear and tear on the operator, while it does a more efficient breaking job requiring less energy.

The "Gentle Jack" vibrates 99% less, produces 50-90% less noise, has 50% fewer parts, and is more energy and work efficient than a conventional jackhammer.

You Get

1. Energy conservation: Because of its unique design and the use of a smaller compressor, the "Gentle Jack" jackhammer will deliver the same impact on far less energy use. While it takes 100 pounds of air pressure per square inch to drive the standard air hammer, the "Gentle Jack" jackhammer is propelled by half that amount. 84 cubic feet of air per minute are required to drive the standard tools, but it only takes 21 cubic feet per minute for the Gentle Jack.

2. Durability, low maintenance: Standard air hammer machinery vibrates itself and all attached equipment so violently that costly and serious maintenance problems arise almost immediately. "Gentle Jack" vibration is so minimal that you can put a quarter on the top of it while it's operating, and the coin will not fall off. By reducing the vibration, metal fatigue failures are virtually eliminated, and there is far less stress on metals and moving parts. In addition, "Gentle Jack" has fewer parts. Fewer parts and longer part life mean yields less maintenance.

3. Lower costs: Because "Gentle Jack" has half as many parts as a conventional jackhammer, it is far less expensive to manufacture, operate and maintain. "Gentle Jack" has only 27 parts, whereas the standard machines have 42 or 44 parts. The wear parts in the "Gentle Jack" are also inexpensive, as opposed to the parts that would need replacing in a standard jackhammer. To keep a conventional breaker operating over the course of a year might cost ten times what might be spent on parts for the "Gentle Jack". The improved design of the "Gentle Jack" increases the life of the breaker point and chisel by several orders of magnitude.

4. Light and Easy to Handle: Because "Gentle Jack" uses a much smaller compressor, it is therefore lighter to handle and easier to haul. Instead of the common 25 horsepower engine needed to power standard hammers, "Gentle Jack" uses either a 5 hp electric compressor or an 11 hp gas engine. It might take two men to move a 25 hp compressor, one man alone can easily handle "Gentle Jack’s� engine and compressor unit. The tool itself is lighter by several pounds, and the weight of the gad (point for breaking rock) is more than twice as heavy.

5. More work production and less downtime: Because it requires no inter cooler, after cooler or receiver, there is minimal equipment downtime. Because it is lighter and easier to move and operate, there will be less worker downtime. Gentle Jack takes approximately 35 pounds of downward pressure to operate, which means that just about anyone can operate it. And, with less vibration and noise, there is less wear and tear not only on the equipment, but on the operator as well, so there's potentially fewer injuries with less sick time, allowing more productive work time from workers.

6. Environmental consideration: "Gentle Jack� emits very little sound in contrast with today's jackhammers. Sound engineers who measured the noise output of this system compared to the standard system and the relative noise in absolute terms, shows that an un-muffled jackhammer, would be ranked 100; a muffled jackhammer would then rank at 17, which is still loud. "Gentle Jack" ranks at 3.13.

One of the key differences is that this tool utilizes heat and doesn't exhaust it with a loud bang. The air input temperature in the "Gentle Jack's" system is 210 degrees Fahrenheit, while standard equipment uses a cool 80 degrees.

When air is compressed, it heats up. Conventional compressors and breakers throw away most of this heat energy and compression energy contained in the air to drive the breaker.

The exhaust air is at ambient temperature and atmospheric pressure. This eliminates freeze up and exhaust noise. The problems of exhaust freeze, exhaust fog and excess dust cannot occur with the Gentle Jack equipment.

The Vibration less operation is based on two key points. There is a constant air pressure between the piston hammer and the housing throughout the stroke cycle, powering the down stroke of the piston but resulting in no variable forces being imparted to the tool or the operator.

The system then allows a variable air pressure, powering the upstroke of the piston which works simultaneously on equal areas of the lower face of the piston and the upper face of the breaker point.

Because of the equal areas, the forces are confined to the hammer being urged in an upward direction thus preparing for another down stroke and the breaker point being urged downward against the rock or concrete.

This concept utilizes all of the compression forces and compression heat invested in the equipment.

A spring-loaded valve and radial ports on a central air tube control air movement through a pneumatic concrete breaker. The tool's hammer is isolated from its housing and rides on a column of hot expanding air.

As a result, the unit is nearly Vibration-less. Traditionally, jackhammers have employed a reciprocating, pneumatically-driven piston, striking many blows each minute, to break concrete. This new design employs fewer but heavier blows to accomplish the same function.

In conventional jackhammers, the 4 to 5-lb. hammer usually has a stroke of 2 to 3 inches and requires a 25-hp compressor and H.R.H. to provide input air at about 80F. The Vibration less jackhammer employs a 17-lb. hammer moving through a stroke of 11 inches. The breaker point also weighs about 17 lbs.

The design requires hot (250F) input air, which is allowed to expand adiabatically against the hammer. After the hammer has been lifted into position for a stroke, it's driven down by 50-psi input air. Input air pressure is held constant at all times.

The hammer is not mechanically linked to the casing of the tool and the air is exhausted for atmospheric pressure. So there's very little vibration transmitted up the tool to the operator. In fact, one can balance a quarter atop the unit while it's breaking concrete.

Pressurized air introduced to the tool from the compressor through an insulated line exerts force against the external shoulder of hammer and internal shoulder of the housing, forcing the hammer against the breaker point.

The point is caught by a retainer hook. When the operator applies 30-lb. downward force, the shoulder on the breaker point is stopped by rubber bumper rings.

Radial ports and internal annulus on the hammer are then in register with the upper cross port in the central air tube, permitting pressurized air to flow down the center tube to depress the valve piston against a spring until it hits stop.

• 99% REDUCTION IN CASE VIBRATION

• Over 50% REDUCTION IN NOISE EMISSION

• 73% REDUCTION IN ENERGY INPUT

• 50% LESS PARTS IN STRUCTURE

• 100% INCREASE IN SURVIVAL PARTS

GENTLE JACK Specification Chart Model VHB-80

Breaking Rate:

The Gentle Jack will hold its own against a McDonald 60 lb. hammer and will do 90% of what an 80 lb. will do but without the wear and tear on the operator or the equipment.

Breaker Weight	80 lb.
Power Unit Weight	135 lb. to 275 lb.
Breaker with Gad Size	41"
Power Unit Size	3' x 2' x 1.5'
Power Requirement	5 hp electric or 11 hp gasoline
Noise at 7 meters	80 d.b.a
Noise at 1 meter	96 d.b.a.

Breaker Weight

80 lb.

Power Unit Weight

135 lb. to 275 lb.

Breaker with Gad Size

41"

Power Unit Size

3' x 2' x 1.5'

Power Requirement

5 hp electric or 11 hp gasoline

Noise at 7 meters
80 d.b.a.
Noise at 1 meter
96 d.b.a.

Makes half the audible noise of a conventional hammer

Vibration Amplitude	.003"
Operator Force Required	35 lb.

Energy Feedback to operator: 3 ft. lb./min. - Conventional hammers are more like 1500 foot-lbs./min.


Parts in Breaker	27
Operating Control	Automatic

Functions of 80# "Gentle Jack"
Some require attachments:

Breaking concrete Cutting asphalt paving Compacting - tamping Driving stakes - setting forms Driving posts Driving pipes for water wells Driving interlocking shoreline steel Cutting tree roots Cutting frozen earth Cutting stone

Drilling holes in rock and other material Cutting rebar and concrete Cutting off rivet heads and bolts Boulder breaker Grizly Mining Equipment Chipper (8 lb. - 20 lb.) Available soon Stopper Rock Drill

Next, air flows into the space between the rear face of the breaker point and the lower hammer face. As air expands, it raises the hammer, the internal hammer annulus passes the upper port in center tube, cutting off air flow through this passage. The hammer operated by expansion of hot input air.

Standard, heavy-duty concrete breakers deliver 87 ft-lb. impact with 75 to 100 psig input air. Our breaker produces 135 ft-lb. impact with 50 psig air, 194 ft-lb. with 75-psig air.

Expanding air under the hammer raises it to near top position in housing. Air pressure beneath the hammer drops from 50 to 0 psig and air temperature drops from 250 to 90F as air expands adiabatically.

As hammer rises, pressurized air outside the hammer, but inside the housing, is forced into the air supply line. This air movement ensures constant down force on the hammer throughout the stroke cycle and constant up force on the cylinder housing.

Lower control valve's piston begins rising as pressure on it decreases. After the hammer reaches top of stroke, 50-psig air acts on the hammer shoulder to start it moving down toward breaker point. The control valve's piston reaches its top position.

As the hammer descends, air below the hammer is forced past the valve piston's stem and out through ports in the breaker point shoulder to atmosphere. Because exhaust is at atmospheric pressure, there's no detonation or exhaust noise.