Abstract: A regulator arrangement (14) for a servo system (10) having a first stage valve spool piston (44) for developing a primary operational fluid (P.sub.c) and a second stage valve spool piston (70) for developing secondary operational fluid P.sub.cr having a constant fluid pressure. A control valve (109) selectively connects a first chamber (100) of a cylinder housing bore to either the primary operational fluid pressure P.sub.c or a reference fluid pressure P.sub.B to develop a fluid pressure P.sub.x in first chamber (100) while a second chamber (102) is connected to the secondary operational fluid (P.sub.cr). A load piston (96) responds to a pressure differential (P.sub.x -P.sub.cr) by moving to either expand or contract the second chamber (102) and produce a fluid pressure (P.sub.crx) in the secondary operational fluid. The fluid pressure P.sub.crx is communicated to the second valve piston (70) to correspondingly allow either additional primary fluid (P.sub.

Abstract: A field subassembly is assembled by positioning two coil supports adjacent respective core end faces of a ferromagnetic core. The core-engaging surfaces of the coil supports and the core end faces have respective surfaces which are uninterrupted by projections. During the assembly of the field, fasteners are pushed into the respective coil supports and the core such that the fasteners engage mounting holes in the coil support with a press-fit. After the field is wound, a brush holder subassembly is also pressed onto the fasteners and the resultant core subassembly is connected to a field housing by driving the fasteners in a conventional fashion. In the preferred embodiment, the fasteners provide a three-point contact with mounting holes formed in the coil supports and the brush holder subassembly.

Abstract: A field subassembly is assembled by positioning two coil supports adjacent respective core end faces of a ferromagnetic core. The core-engaging surfaces of the coil supports and the core end faces have respective surfaces which are uninterrupted by projections. During the assembly of the field, fasteners are pushed into the respective coil supports and the core such that the fasteners engage mounting holes in the coil support with a press-fit. After the field is wound, a brush holder subassembly is also pressed onto the fasteners and the resultant core subassembly is connected to a field housing by driving the fasteners in a conventional fashion. In the preferred embodiment, the fasteners provide a three-point contact with mounting holes formed in the coil supports and the brush holder subassembly.

Abstract: An orbital-action reciprocating power saw includes a motor-driven transmission that causes a saw blade carrier to reciprocate along an axis of reciprocation and move in a direction transverse to the axis of reciprocation to provide an aggressive cutting action. The transmission includes a rotary-to-reciprocation drive mechanism defined by a rotatably driven gear having an eccentrically mounted pin that engages a slotted yoke connected to the saw blade carrier. The saw blade carrier is mounted in a `floating` bearing that accommodates both reciprocation and movement in a direction transverse to the reciprocation axis. A rocker arm is pivotally mounted intermediate its ends with one end engaging the floating bearing mount and the other end engageable with an axial-face cam portion of the rotatably driven gear. The rocker arm is effective to move the saw blade carrier in a direction transverse to the axis of reciprocation to provide the desired orbital action.

Abstract: A field subassembly is assembled by positioning two coil supports adjacent respective core end faces of a ferromagnetic core. The core-engaging surfaces of the coil supports and the core end faces have respective surfaces which are uninterrupted by projections. During the assembly of the field, fasteners are pushed into the respective coil supports and the core such that the fasteners engage mounting holes in the coil support with a press-fit. After the field is wound, a brush holder subassembly is also pressed onto the fasteners and the resultant core subassembly is connected to a field housing by driving the fasteners in a conventional fashion. In the preferred embodiment, the fasteners provide a three-point contact with mounting holes formed in the coil supports and the brush holder subassembly.

Abstract: A hammer-drill is adapted for drilling a hole in masonry and subsequently driving a threaded masonry fastener therein. The hammer-drill has a driving output shaft nested concentrically within a driving output sleeve. The shaft and sleeve both extend forwardly of the tool housing, and both are driven continuously by respective gearing in the tool. The sleeve, however, is driven at a substantially lower rpm than the shaft and at a higher torque. After the hole is drilled, a tubular member is releasably and drivingly coupled to the sleeve. The tubular member encloses the masonry drill bit, which is continually rotated, and the drill bit need not be removed from the tool to seat the fastener. The tubular member has a forward portion provided with a socket for the head of the masonry fastener.

Abstract: A fuel/air ratio control apparatus for a reciprocating engine used in light aircraft including a fuel metering apparatus (32) and a fuel/air ratio controller (40). The controller (40) generates an electrical signal (Wf/Wa) indicative of a desired fuel/air ratio based upon the flight condition of the aircraft and the metering apparatus (32) meters fuel flow (Wf) according to the mass airflow ingested into the engine. The desired fuel/air ratio is a best power ratio (Wf/Wa (2)) for takeoff and climb conditions and a best economy ratio (Wf/Wa (3)) for cruise conditions as derived from the exhaust gas temperature. These ratios are limited by a ratio (Wf/Wa (1)) based upon the maximum cylinder head temperature tolerable for a particular flight condition.

Abstract: A fuel/air ratio control apparatus for a reciprocating engine used in light aircraft including a fuel metering apparatus (32) and an electronic fuel/air ratio control (39). The control (39) generates an electrical signal (Wf/Wa) indicative of a desired fuel/air ratio based upon the flight condition of the aircraft and the metering apparatus (32) meters fuel flow (Wf) according to the mass airflow (Wa) ingested by the engine. The fuel metering apparatus (32) positions a metering valve (348) by means of a force balance of opposing forces developed by an air diaphragm (330) and a fuel diaphragm (336). The fuel diaphragm (336) is subjected to the differential pressure of a metering head pressure (Pu) and a fuel output pressure (Pm). The output pressure (Pm) is regulated by a controlled orifice (343) influenced by a proportional solenoid (406) whose armature valve (341) is positioned by the electrical signal (Wf/Wa).

Abstract: An electric saw or other power-operated tool carries a spring-loaded pin for selectively locking the output spindle against rotation and facilitating removal of the blade. The locking pin comprises a bent wire-formed element pivotably retained in the housing. One end of the pin is slidably received within a flanged bearing opening in the stationary guard. When the pin is pivoted by the operator, the end of the pin is received within an aperture in the inner flange washer, the latter forming part of the clamping mechanism for fixedly securing the blade on the spindle.

Abstract: A power-driven drill and screwdriver includes a housing and a drive motor mounted in the housing. A case is attached to the housing and has a spindle bearing mounted therein. A first clutch is rotatably mounted in the case axially of the bearing and is operatively connected to the drive motor. An output spindle is journalled in the bearing and has a flange formed thereon. A second clutch is formed on the flange so as to be adjacent the first clutch. The output spindle is slideably mounted in the bearing so as to cause the second clutch to be movable relative to the first clutch between a first location whereat the second clutch firmly engages the first clutch and a second location whereat second clutch is disengaged from the first clutch. A spring resiliently biases the second clutch into the second location. An eccentric member is journalled in the case and is rotatable from one position corresponding to the screwdriving mode of the tool to another position corresponding to the drill mode of the tool.

Abstract: A combination power tool has a housing defining a bore with an annular bearing member mounted in the bore. A first clutch is rotatably mounted in the housing and a second clutch is rotatably mounted in the annular bearing member and movable relative to said first clutch between a first position whereat the second clutch firmly engages the first clutch and a second position whereat the second clutch is disengaged from the first clutch. A spring biases the second clutch into its second position. The annular bearing member is movably mounted in the bore for engaging the second clutch member to counteract the urging force of the spring and to displace the second clutch from the second position into the first position. A face cam formed on the annular bearing member and a cam follower is located on the housing for coacting with the face cam to guide the annular bearing member when the same is moved along the bore to bring the second clutch into its first position.