Abstract: An indexing mechanism for the rotatable element of a machine tool wherein a shaft is coaxial with the element and has formed thereon a helicoidal groove. A control member is engaged in said groove and moves alternately therein to transmit an oscillating rotative movement to the shaft to effect go-and-back movements along the groove in a direction parallel to the axis of rotation of the rotatable element. A control cam effects go-and-back movements which are synchronized with the movements of the control member. A driving member is mounted on the shaft for rotation therewith and is capable also of axial movement between one position in which it is rigid with the element and a second non-rigid position. The axial movement of the driving member is controlled by the cam. Accordingly, during the go movements of the control member and of the cam, the driving member is rigid with the element.

Abstract: A screw or nut runner for tightening screw joints wherein a speed related braking force is applied upon those rotating parts of the nut runner that are positively coupled to the screw joint, thereby avoiding the influence of the inertia factor upon the obtained torque level. The power transmission of the screw or nut runner comprises a magnetic release clutch. A centrifugal brake is located after the release clutch in the power train for preloading the release clutch by generating a speed related braking force.

Abstract: Disclosed herein is a lawn mower comprising a cutter blade housing supported for movement along the ground, a cutter blade assembly including a cutter blade, and a gear housing fixed to the cutter blade and including therein a first pinion and a second pinion in mesh with the first pinion, a drive shaft extending into the gear box and having fixed thereon the first pinion, and mechanism mounting the second pinion in the gear box about a rotary axis fixed with respect to the gear box, which mechanism is operable to selectively prevent and permit rotation of the pinion relative to the gear box.

Abstract: Disclosed herein is a lawn mower comprising a blade housing supported for travel over the ground, a drive shaft mounted for rotation by the blade housing and including thereon a clutch drum, an engine drivingly connected to the drive shaft for rotation thereof, a cutter blade located in the blade housing and mounted for rotation coaxially with and relative to the drive shaft, a clutch shoe connected to the cutter blade for common rotation therewith and for movement relative to a position of engagement with the clutch drum, a spring urging the clutch shoe into the position of engagement, a brake surface fixed to the clutch shoe, and a brake member movable between a first position wherein the brake member is spaced from the brake surface, and a second position wherein the brake member engages the brake surface to brake rotation of the cutter blade and to displace the clutch shoe from the position of engagement against the action of the spring.

Abstract: A clutch operable manually to couple and uncouple a driven member from a drive shaft and to stop movement of the driven member upon uncoupling of the same. A driving clutch plate and a reaction member are fixed on the drive shaft and axially spaced apart thereon. A driven clutch plate and a cooperating actuating and output member, mounted on the drive shaft between the driving clutch plate and reaction member, provide an axially expansible and contractible clutch assembly, the actuating and output member having driving engagement with the driven member. Actuator means, carried by the driven clutch plate and the actuating and output member, limits rotary movement between the driven clutch plate actuating and output member, and causes the clutch assembly to vary between expanded and contracted conditions. A stopping device is arranged to prevent rotation of the driven clutch plate.

Abstract: A brake device for use in a portable bush cutter having a construction in which the driving force of the engine is transmitted through a centrifugal clutch assembly to the drive shaft sheathed in the elongated main pipe, then changed in direction by a bevel gear means and further transmitted to the rotary blade. Said brake device is installed at a location between either the drive shaft or the rotary blade shaft and the centrifugal clutch assembly. This brake device comprises a brake drum and a brake shoe or brake band and is operated simultaneously with the engine throttle valve by a lever secured to the handle grip, so as to apply the brakes to the rotary blade without stopping the engine.

Abstract: A safety release arrangement for a centrifugal clutch having clutch shoes moving radially outwards under centrifugal force to engage a clutch drum. Each clutch shoe is divided into two mutually radially movable parts which during normal operation are locked together by a locking member and move as a unit. When the locking member is actuated by a safety release device the radially inward lying primary clutch shoe part is released with respect to the radially outward lying drum-engaging secondary clutch shoe part and can move radially outwards. By various arrangement the primary shoe is caused to draw the secondary clutch shoe radially inwards out of engagement with the clutch drum.

Abstract: Disclosed herein is a chain saw comprising a frame having a handle, a clutch driven by a drive shaft driven by an engine mounted on the frame and including a clutch shoe movable in response to clutch shoe rotation relative to a position of driving engagement with a rotatable clutch drum and selectively operable means for preventing engagement of the clutch shoe with the clutch drum, a bar mounted on the frame for movement between a first position spaced from the handle and a second position adjacent to the handle, means operably connected to the bar for operating the means for preventing engagement of the clutch shoe with the clutch drum to prevent clutch shoe engagement when the bar is in the first position and to permit clutch shoe engagement when the bar is in the second position, and means operable for braking rotation of the clutch drum when the bar is in the first position.

Abstract: Disclosed herein is a centrifugal clutch comprising a rotatable driver, a clutch drum carried for co-axial rotation relative to the driver, a clutch shoe carried by the driver for common rotation therewith and for movement between a position engaging the clutch drum so as to effect common rotary movement of the driver and the clutch drum and a second position spaced from the clutch drum, a loading shoe, a pivotal connection between the clutch shoe and the loading shoe to afford relative movement therebetween, a trigger movably mounted on one of the loading shoe and the clutch shoe for movement between a first position engaged between the clutch shoe and the loading shoe so as to transmit centrifugal force from the loading shoe to the clutch shoe and a second position of non-engagement between the clutch shoe and the loading shoe, and interengaging surfaces on the loading shoe and on the driver operable when the trigger is in the second position for pivoting the loading shoe in response to radially outward mov