Abstract: A muffler is integrally incorporated with a pneumatic tool by cooperating with the tool housing intermediate the air exhaust chamber for the air motor and atmosphere. An inwardly dished muffler shell includes an exhaust inlet for receipt of exhaust air from the air motor. The shell is selectively positionable and may be combined with screen and additional muffler material as well as a retaining plate in any of a number of combinations to provide distinctive muffling characteristics for the air tool.

Abstract: A piling rig comprises two sound-reducing enclosures arranged one over the other. In use the bottom enclosure is arranged around a row of piling and the top enclosure surrounds the piling hammer as it moves along the row of piling for pile-driving or pile-extraction purposes.

Abstract: A noise reduction device for use with an impact tool which comprises a deformable block having a flat face and an opening therein for accepting the set of the tool, and a cylindrical housing extending from the block and sealed about the tool, with an open conduit extending from said housing.

Abstract: A rock drilling apparatus has a noise reducing drill rod cover which comprises a pair of elongated strips, each of which, when in an extended condition in the longitudinal direction thereof, form part-cylindrical members which matingly engage the other strip to form a generally cylindrical cover around the drill rod. Spool means is provided, preferably in the area of the centralizer, to selectively roll the elongated strips thereon, the strips being flattened when rolled onto the spool means. The elongated strips are rolled onto simultaneously driven spools, and comprise either metallic strips, metallic strips covered with rubber on one or both surfaces thereof, or elastic strips having spaced metallic inserts embedded therein.

Abstract: A relatively quiet-operating rotary hammer for use in apparatus for securing T-edging and similar edging bands. The hammer includes a pivoted hammer head that is intermittently and continuously impacted to provide a hammering action. The hammer is impacted by a rotary structure carrying spaced hammering elements for forcibly pivoting the hammer head.

Abstract: In an explosive charge-driven fastening element setting gun having a casing and a muzzle tube axially displaceably mounted in the casing, a damping housing is arranged to receive explosive gases passing laterally out of the gun. The damping housing surrounds the gun and is formed of two parts, one fitting into the other in a telescoping manner. One part is attached to the muzzle tube and the other part is fixed to the casing. Packing is secured to one of the parts and extends into contact with the other part in the region where the parts are telescopically fitted together.

Abstract: A drilling tool for use in boring holes is formed of an axially elongated drilling member and a holder or input unit. The input unit laterally encloses the rearward end of the drilling member and is formed of at least two materials, one having a higher thermal conductivity than the other. The higher thermal conductivity material is in contact with the shank of the drilling member and extends radially outwardly to the outer surface of the input unit. The higher thermal conductivity material can have various shapes, for instance, that of a coil, spaced disks, a sleeve with inwardly extending webs or an inner sleeve and an outer sleeve spaced apart and joined by a flange-like web. The second material may be a plastic and can be fixed into holes or openings formed in the first material.

Abstract: A pneumatic tool having an exhaust air noise attenuating system in which air exhausting from a rotary air vane motor is caused to pass in order through an exhaust port, past a flexible leaf damper overlying the exhaust port into a wave modulating chamber containing an air diffusion screen, and finally through ports exiting to atmosphere. The damper is illustrated in a first form as applied to the motor of an impact wrench; and is illustrated in a second embodiment as applied to a grinding tool.

Abstract: A modular leads frame for a pile driving machine is provided with a plurality of noise abating shield members which surround the driving hammer of the pile driving machine with certain ones thereof being moved with the driving hammer throughout its driving stroke in order to abate the noise resulting from the driving impact of the hammer against the pile.The pile is fed into position by first hoisting the movable shield members and the driving hammer to the top of the leads frame, hoisting the pile to be driven into a vertical position after attaching the pile hoist line to one end of the pile at ground level and thereafter actuating a pile feeder which positions the vertically hoisted pile within the leads frame and in alignment with the driving hammer.

Abstract: The present invention is a projectile type demolition tool. A projectile with an enlarged upper cross-sectional area is slideably mounted within and extendable from an inner cylinder. The lower portion of the projectile is extendable through a guide connected to the bottom of the inner cylinder. Upon pressing a working end of the projectile against a work piece to be broken, the projectile recedes upward in the inner cylinder until the enlarged upper area moves above a source of low pressure gas connected through the inner cylinder. The low pressure gas continues to move the projectile upward in the inner cylinder to a cocked position. In the cocked position, a reduced area upper portion of the projectile acts against a moderately high pressure gas injected into a combustion chamber. Thereafter, a high pressure gas is created by an internal combustion in the combustion chamber, which high pressure gas drives the projectile downward into the work piece.

Abstract: A method of modifying a percussion tool to provide noise reduction, and a percussion tool having effective noise damping characteristics.In the method of the present invention, a troublesome noise frequency radiated by the tool is identified, and a resonant bending mode shape for the tool is determined, which bending mode shape corresponds to the identified noise frequency. The tool is then assembled and a structural discontinuity is introduced at a point along the length of the tool which is a predetermined axial distance from a selected antinode of the bending mode shape to provide an impedance mismatch at that point.The tool, which is of predetermined length, is formed of one or more sections, each of which is of a selected length. The lengths of the sections are carefully determined such that when the tool is in assembled condition, impedance mismatches are provided at selected points along the length of the tool, to provide noise reduction of several troublesome noise frequencies.

Abstract: An air hammer having a main body including an elongated cavity with a ram slidably mounted therein. The ram is driven by compressed air delivered through inlet means to the cavity in such a way as to drive the ram up and down to impact a tool. Exhaust from the hammer is directed into a plurality of elongated expansion chambers which are positioned within the body of the hammer. The expansion chambers extend to each end of the hammer body and exhaust to the atmosphere through open ports. Inserts are placed within the elongated expansion chambers to divide the chambers into properly sized cavities for greatest sound attenuation. Holes extend through these inserts for the eventual passage of exhausting air therethrough. The inserts are of neoprene having a durometer hardness of from 75 to 90. The size of the expansion chambers and the configuration and positioning of the inserts are intended to provide a muffling of the noise and shock of the exhaust.

Abstract: An elastomer muffler for the exhaust of a pneumatic percussive tool, which comprises an outer and an inner side wall. The cross-sections of the side walls are C-shaped and the side walls are longitudinally unified for forming a cavity therebetween. The muffler is detachably mounted to the tool by resilient snap action. To advantage, the muffler may be used in connection with a pusher leg arrangement for a rock drill. The muffler, then, is mounted on the pusher leg and the inlet mouth thereof is arranged substantially concentrically with the axis of the hinge connection between the pusher leg and the rock drill but spaced axially from said hinge connection. The exhaust port of the rock drill is also substantially concentrically with the hinge connection but spaced axially therefrom.

Abstract: An improved fluid operated rock drill apparatus having all fluid connections thereto secured to the yoke of the drill assembly by a unitary connector means. The yoke is centrally located so that the high pressure fluid being directed to the rock drill hammer piston flows through a path of reduced length resulting in a more efficient operation.

Abstract: A muffler system for attenuating exhaust noise from pile driving apparatus including an exhaust passage therein having perforated straight sections and unperforated curved sections. The exhaust passage is surrounded with acoustical absorbing material and screen means is interposed between the exhaust passage and the absorbing material. The muffler system can be adapted for modular construction whereby modular muffler section can be stacked and connected in series to provide a muffler passage of desired length to fit within a confined width.

Abstract: Noise radiated into the atmosphere from a pile during pile-driving is inhibited by a tubular cover of flexible material having internal dimensions sufficient to pass, with an intervening air space, over a pile to be driven and an extended length sufficient to enclose a pile over its entire length, said cover being suspended from a hammer driving unit or a pile cap and being axially collapsible to reduce its length as the hammer driving unit or pile cap moves downwards while a pile enclosed in the cover is being driven into the ground.

Abstract: Impact driven tools of the type generally comprising a bitter end bounded by a collar and a shank and a tip are provided with internal silencing means comprising an opening in the bitter end, said opening filled with a sound attenuating material, which is preferably steel shot loosely packed in the opening and retained therein by a force fit plug secured by a weld. The opening is preferably axial and extends through the bitter end to or below the collar. In large diameter impact driven tools multiple openings are provided parallel to the axis and terminating at staggered points. Each such hole is filled with a sound attenuating material, such as steel shot. The rams of impacting apparatus, or air hammers, are also provided with internal silencing means comprising at least one opening, each such opening being filled with sound attenuating material, which is preferably steel shot loosely packed and retained by a force fit plug secured by a weld.

Abstract: A lubrication system for rock drill machines powered by pressurized fluid, the lubricating system comprising a reservoir of lubricant, means for pressurizing the lubricant in the reservoir, conduits for feeding lubricant from the reservoir to individual dosage units, each connected to a particular lubrication point of the rock drill machine, the lubricant being supplied under pressure from the dosage unit by way of a rod- or plunger-operated piston reciprocable in the dosage unit, the end of the piston rod engaging an adjustable abutment, the dosage units being mounted such as to be reciprocable in unison with the rock drill by way of the drill feed unit.