Vibrationless pneumatic tools

A high efficiency pneumatic system comprising:

• a pneumatic motor;
• a drive element in said pneumatic motor having an oscillatory motion, said oscillatory motion being produced by intermittent substantially adiabatic expansion of a gas having pressure and temperature valves greater than the ambient pressure and temperature valves in order to actuate said drive element against an opposing force;
• force transmitting means to convey said opposing force to said drive element without conveying said oscillatory motion to the source of said opposing force;
• a gas mass confining chamber;
• a movable element to vary the gas-containing volume of said chamber to compress gas therein;
• heat migration preventive means to prevent loss of heat energy from said gas in said chamber so that said gas is compressed substantially adiabatically to retain the heat energy produced during compression;
• a conduit to convey said gas from said gas mass confining chamber to said pneumatic motor with a minimal loss of heat energy;
• valve means to insert heated compressed air into said conduit from said chamber;
• and
• valving means to selectively admit discrete portions of said gas in said conduit to actuate said drive element against said opposing force, said valving means determining that each of said portions of gas admitted by said valving means to actuate said drive element is an amount of gas that will expand to substantially ambient pressure while actuating said drive element to its maximum displacement against said opposing force.

A pneumatic tool system in which undesired transmission of vibrations is eliminated and comprising:

• an outer casing in which vibrations are undesired;
• a vibrating generally cylindrical blow-striking hammer having generally annular cross-section reciprocable in said outer casing;
• a source of gas at a constant pressure in excess of atmospheric pressure and a temperature greater than ambient temperature;
• a coupling chamber into which said gas is introduced to transmit a substantially constant force from said outer casing to said hammer, the magnitude of the coupling chamber force applied to said hammer being determined by the pressure of said gas and a first pressure surface associated with said hammer;
• a round rod coaxial with said outer casing over which said hammer passes;
• and
• a valve assembly in said round rod to control application of said gas to a second pressure surface under said hammer for a predetermined period of time, said second pressure surface being larger than said first pressure surface so that said hammer is driven against the coupling chamber force applied thereto to effectuate the up-stroke of said hammer, said valve assembly also controlling venting of the space under said hammer of exhausting this space during the downstroke of said hammer.

A vibrationless pneumatic paving breaker system comprising:

• a source of compressed gas at a temperature greater than ambient temperature;
• a casing having a force applied thereto;
• a conduit to convey the compressed gas from said source to said casing;
• a generally cylindrical hammer having a generally annular cross section arranged for reciprocable motion in said casing;
• a work bit to break paving upon being struck by said hammer, said work bit being mounted for motion with respect to said casing;
• restraining means to prevent separation of said work bit from said casing;
• an actuating chamber into which said gas is inserted formed between said casing and said hammer with respective opposing surfaces on said casing and said hammer to transmit said force applied to said casing to said hammer, the transmitted force having a constant value dependent upon the pressure of said gas;
• a round rod coaxial with said casing, said hammer reciprocating along said round rod;
• and
• a valve assembly located in a cavity in said round rod and adapted selectively to cause said gas to be inserted under said hammer for a predetermined period of time to impinge upon a surface larger than said opposing surfaces in said actuating chamber to drive said hammer against said constant transmitted force as said gas expands, and to vent the space under said hammer to permit the expanded gas to be exhausted.

A high efficiency pneumatic system comprising:

• a pneumatic motor;
• a drive element in said pneumatic motor having an oscillatory motion;
• means for raising the pressure and temperature of a quantity of air drawn from the atmosphere to values above the pressure and temperature of the atmosphere;
• a conduit to convey air from said quantity of air, at a pressure and temperature above the pressure and temperature of the surrounding atmosphere, to said pneumatic motor with a minimal loss of heat energy;
• and
• valving means to selectively admit discrete portions of said air to said conduit to actuate said drive element against an opposing force, said valving means determining that each of said portions of air admitted by said valving means to actuate said drive element is an amount of air that will expand to substantially atmospheric pressure and temperature while actuating said drive element to its maxium displacement against said opposing force.

A pneumatic tool system comprising:

• a tool casing;
• a blow-striking member positioned for reciprocable motion in said tool casing;
• a work member to be struck by said blow-striking member;
• means for raising the pressure and temperature of a quantity of air drawn from the atmosphere to values above the pressure and temperature of the atmosphere;
• a conduit to convey air from said quantity of air, at a presssure and temperature above the pressure and temperature of ambient air, to said tool casing with a minimal loss of heat energy;
• and
• valving means to selectively admit discrete portions of said air in said conduit to drive said blow-striking member away from said work member against an opposing force, said valving means determining that each of said portions of air admitted by said valving means to drive said blow-striking member is an amount of air that will expand to substantially ambient pressure and temperature while driving said blow-striking member to its maximum displacement against said opposing force,
• whereby the air driving said blow-striking member is exhausted at substantially ambient pressure to eliminate the major source of noise in a pneumatic tool.

A pneumatic tool, in which undesired transmission of vibrations and exhaust noise are substantially eliminated, comprising:

• an outer casing in which vibrations are undesired and to which an operating force is applied;
• a vibrating blow-striking hammer reciprocable in said outer casing, reciprocation of said hammer being produced by intermittent substantially adiabatic expansion of a gas having pressure and temperature values greater than the ambient pressure and temperature values in order to actuate said hammer against said operating force;
• force transmitting means to convey said operating force to said hammer without conveying the vibrations of said hammer to said casing;
• and
• valving means to selectively admit discrete portions of said gas to actuate said hammer against said operating force, said valving means determining that each of said portions of gas admitted by said valving means to actuate said hammer is an amount of gas that will expand to substantially ambient pressure while actuating said hammer to its maximum displacement against said operating force.