Abstract: A linearly moving external part on a multi-cylinder internal combustion engine is contacted with a hand-held rotary encoder, contact tachometer having a hollow handle in which processing circuitry is disposed for converting the rotary encoder output to a waveform signal. This signal, along with a signal responsive to the firing of the number one cylinder, are applied to an engine analyzer processor for display of a single engine cycle of the waveform signal on the CRT oscilloscope of the engine analyzer. The variations in amplitude of the waveform signal correspond to speed variations of the moving part over an engine cycle to give an indication of the relative power contributions of the individual cylinders.

Abstract: A rotary air motor has a stator with a cylindrical inner surface defining a chamber and a cylindrical rotor mounted by hub structure for eccentric rotation within the chamber and end plates closing the opposite ends of the chamber and spaced from the adjacent ends of the rotor by end clearance spaces. The rotor has a plurality of arcuate slots therein extending the length thereof and respectively slidably receiving arcuate vanes arranged so that when the rotor is rotated the outermost edges of the vanes are centrifugally urged into sliding engagement with the inner surface of the stator.

Abstract: A reversible ratchet wrench has a housing containing a ratchet wheel and a reversing pawl unit which includes two pawls respectively connected by leaf springs to a pivotally mounted reversing cam, all in a unitary one-piece construction. The reversing pawl unit is pivotally movable by a reversing lever between first and second conditions, wherein the two pawls respectively engage the ratchet wheel for accommodating rotation thereof in opposite directions. The reversing lever has a cam follower which cammingly engages a cam surface on the housing to resiliently hold the reversing lever in the selected one of its two positions.

Abstract: A tool for rotatably driving a fastening member includes a hollow tubular shank having a socket coupled to one end thereof in communication therewith for receiving an associated rotatable fastener member. A helical compression spring is disposed coaxially within the shank, having the outer end thereof affixed to a magnet disposed for magnetic engagement with the fastening member received in the socket, and having an end coil at the other end thereof disposed outside the other end of the shank with an outer diameter greater than the inner diameter of the shank, the other end of the shank being received in a bore in a handle for cooperation therewith to trap the end coil of the spring, therebetween.

Abstract: A reversible ratchet wrench has a housing containing a ratchet wheel and a pawl selectively pivotal between first and second conditions, respectively engageable with the ratchet wheel for accommodating rotation thereof in opposite directions, with the pawl undergoing a ratcheting movement in response to rotation of the ratchet wheel. The pawl is biased by either a torsion band or an over-center leaf spring to the selected condition. A reversing member has a lever arm pivotally movable between first and second positions to pivot the pawl. The pawl and the reversing member respectively have first and second drive portions thereon which respectively form diametrically opposed sectors of a common cylinder, each less than 180.degree.

Abstract: The open-end wrenching head includes two jaws and a throat interconnecting the jaws. The jaws include planar jaw driving surfaces each with a roughened region thereon adjacent to the throat and an unroughened region adjacent to the outermost end of the jaw driving surface, each of the roughened and unroughened regions being constructed and arranged to engage a portion of a selected side of a fastener. The throat may include either an arcuate surface or two planar throat driving surfaces. Each of the roughened regions has a coefficient of friction substantially greater than that of the unroughened regions and may be formed by deposition of an abrasive material by any of a number of processes or by deformation of the jaw driving surface by any of a number of processes.

Abstract: The tool includes a housing having two substantially semi-cylindrical members. An air motor in the housing has motor end members located adjacent each end thereof. Two O-rings, respectively disposed between the motor and the end members, are squeezable axially so as to be forced radially outwardly to abut the housing. A manifold includes a chamber of a size that dampens Helmholtz frequencies in the exhaust air. A bearing block includes an outer surface configured to transfer operating loads from a crank shaft extending through the bearing block to the housing. Each of the members of the housing has an arm with a cylindrical opening for receiving a rotatable drive body. The drive body has a knob including a shaft having an ear cooperating with an O-ring in the drive body for preventing the knob from inadvertently rotating between operating positions while the tool is in use. An O-ring between the knob and the drive body isolates the housing from shock to the knob resulting when the tool is dropped.

Abstract: A torque wrench has a battery-powered sensing circuit which produces a torque signal proportional to the level of the torque applied. A reference signal corresponding to a predetermined torque level is subtracted from the torque signal to produce a difference signal which is, in turn, compared with a compensation signal which is proportional to the rate of change of the torque signal and is produced by differentiating the torque signal. When the value of the difference signal exceeds the value of the compensation signal, an indicator is triggered to produce a tactile indication, the indication being produced prior to the time that the torque signal reaches the reference level by a predetermined time period.

Abstract: The open-end wrenching head includes two jaws and a throat interconnecting the jaws. The jaws include planar jaw driving surfaces each with at least one serrated region thereon constructed and arranged to engage a portion of a selected side of a fastener. The throat may include either an arcuate surface or two planar throat driving surfaces having serrated regions thereon. Each of the serrated regions on the driving surfaces may include symmetrical or asymmetrical grooves. The plane of these grooves may be parallel to the driving surfaces or at an angle of about 1.degree. to 3.degree..

Abstract: The one-piece, open-end wrenching head includes two substantially equal-length jaws with a throat recess therebetween. The jaws respectively include driving surfaces spaced apart a distance slightly greater than the across-flats dimension of an associated hexagonal fastener, with each driving surface having a length no greater than the length of one of the flat sides of the associated fastener and having a serrated region thereon. The distance from the deepest part of the throat to an imaginary line connecting the distal ends of the jaws is approximately 0.86 times the across-flats dimension of the fastener.

Abstract: The fatigue-resistant spindle end of the invention is an elongated body having an axis of rotation. The spindle end comprises a drive engaging portion at one end, a male tool engaging tang at the other end, and a torque transfer section disposed therebetween. The torque transfer section includes a cylindrical journal portion and a frustoconical transition portion. The transition portion retains the geometric characteristics of both the tang and the cylindrical journal portion and blends those geometric characteristics so as to eliminate sharp discontinuities which may function as stress concentrators. In one embodiment of the invention, a stop barrel is also included to prevent a socket or other tool from engaging the transition portion.