Milwaukee Electric Tool Corporation

Other

Bernhard Palm

Richard H Jungmann

Ken R Jordan

Light for a power tool

A clamp for the blade of a hand held reciprocating tool includes a spindle coupled to the drive mechanism. A slot is formed in the spindle for receiving the blade tang and a collar is threadably received on the spindle. A blade clamping member is disposed between the collar and the blade and includes an engaging member for engaging a hole in the blade tang and a pair of ears which engage the upper and lower shoulders of the blade tang to provide three points of engagement when the collar is tightened. The clamp also includes a nose section which engages the blade at its junction with the tang to provide reinforcement against breakage.

Keyless clamp assembly for reciprocating tool

Disclosed herein is an impact absorption mechanism and a power tool including an impact absorption mechanism. When a tool bit binds a high energy impulse of short duration is generated that may damage components of the power tool. The impact absorption mechanism absorbs this high energy impulse and prevents damage to other components of the power tool.

Impact absorption mechanism for power tools

Each end of the cross bore in the end of the driver or extension is coined to capture the balls in the cross bore. The combined diameters of the balls are equal to the distance between the opposed flat faces of the driver end. One of the faces has a groove in which the lock tab or key is received. The key is part of the control means which includes annular spring seat captured inside the sleeve mounted on the driver. The compressed spring inside the sleeve biases the seat and key to the left so the key overlies the balls. The spring force acts to rock the tab against the ball to project the other ball from the driver end into locking engagement with a recess in the socket. When the projecting ball is pushed into the cross bore as the socket is being mounted the other ball is pushed out of the bore to raise the tab to be engaged by the socket. This causes the tab and seat to be moved to compress the spring. The tab and the seat can move with and with respect to the sleeve. The sleeve is preferably cylindrical with a washer fixed on the shoulder at the rear end of the sleeve by crimping the sleeve. The tapered sleeve construction is more difficult to produce.

Snap-on quick release extension and drivers

The power pack (battery pack) which is removably mounted on the lower end of the pistol grip portion of the hand power tool is provided with a light mounted in a slider mounted in the power pack for movement between a retracted position in which in conforms to the contour of the power pack and a projecting position in which the light is connected across the battery supply and projects the light beam upwardly and forwardly of the tool to illuminate the work area.

Power tool with light

The motor drives the crown gear which has an upwardly projecting eccentric drive pin which drivingly engages the channel fixed on the spindle which reciprocates in the fixed tube and supports a saw blade. The induced vibration is counterbalanced by the reciprocating counterbalance which slides on the outside of the tube. The crown gear has a cylindrical drive member which engages the cylindrical hole in the transfer block. The transfer block is moved in an orbital path and the opposed parallel sides engage and reciprocate the counterweight. The crown gear and cylindrical drive member have material removed to counterbalance the two drives.

Counterbalanced reciprocating mechanism

The reciprocating saw incorporates a counterbalanced reciprocating drive having a jackshaft on which primary and secondary wobble plates are mounted. The wobble plates drive a reciprocating saw spindle and a concentric counterweight in opposite directions to cancel out the induced vibrations. The spindle reciprocates in a bearing sleeve having a slot through which the primary wobble arm projects to drive the spindle. The primary wobble arm projects through a longitudinal slot in the spindle and engages the opposite side of the spindle so the spindle cannot rotate as it reciprocates. The counterweight slides on the outside of the sleeve and has a slot which slides over the primary arm. The secondary arm drives the counterweight. The arms are out of alignment to permit their strokes to overlap without collision. The wobble plates are angled out of 180.degree. so the spindle and counterbalance reverse at the same time. The cutting stroke and speed are increased and vibration is insignificant. The spindle drive has utility apart from the counterbalanced drive.

Wobble plate drive

The reciprocating saw incorporates a counterbalanced reciprocating drive having a jackshaft on which primary and secondary wobble plates are mounted. The wobble plates drive reciprocating saw spindle and a concentric counterweight in opposite directions to cancel out the induced vibrations. The spindle reciprocates in a bearing sleeve having a slot through which the primary wobble arm projects to drive the spindle. The counterweight slides on the outside of the sleeve and has a slot which slides over the primary arm. The secondary arm drives the counterweight. The arms are out of alignment to permit their strokes to overlap without collision. The wobble plates are angled out of 180.degree. so the spindle and counterbalance reverse at the same time. The cutting stroke and speed are increased and vibration is insignificant. The drive has many other uses.

The power saw is provided with a shoe pivotally mounted on a post which is mounted in a cavity of the nose section of the gear case of the saw. The post has a multiplicity of grooves separated by lands which are flat between the grooves. A lock pin is mounted in the nose section transverse and spaced from the post. When the pin is in its normal locking position, the round exterior of the pin engages one of the grooves on the post to retain the post and shoe in position relative to the saw. The lock pin has a flat section which is parallel to and spaced from the flats on the post when the pin is rotated to the release position freeing the post and shoe for movement to adjust the position relative to the saw. A lever is mounted on the end of the pin which projects through the side of the gear case. The inside of the lever has a dimple which engages the soft boot covering the gear case. This develops enough friction to hold the lever in its normal position until manually actuated to release position allowing adjustment of the shoe position.

Quick change guide shoe

The in-line saw has a handle, a motor housing and a gear case which contains a drive mechanism which imparts a reciprocating action to the blade. The drive mechanism generates heat. The gear case is covered by an insulating boot which has internal ribs which contact the gear case and form air flow channels. The motor housing has air openings near the handle and the fan mounted on the motor drive shaft draws cooling air through the slots over the motor and out the space between the gear case and the motor housing except that the boot extends partially over the slot to divert air to the space between the boot and the case. The cooling air leaves the cooling space at the front of the boot to blow sawdust from the area of the blade. The boot is electrically insulating and covers the metal gear case.

Insulated cooling boot for power tool

The chuck body is centered on the power tool drive spindle by placing the smooth bore in the body over the smooth cylinder on the spindle with the recesses on the body axially moved onto the lugs (splines) on the shoulder of the spindle. The retaining screw is threaded into the end of the spindle and the screw head forces the chuck body against the shoulder. Neither the screw nor the bore/cylinder transmit torque; only the drive lugs transmit torque so the chuck can't jam on the spindle. This mount works with keyed chucks or keyless chucks as illustrated where the three inclined jaws are threadably engaged by split nut having a retainer pressed thereon. A clutch sleeve is biased rearward from the split nut and is moved towards the nut to engage interference lugs on the sleeve with lugs on the nut to restrain nut rotation to open or close the jaws. As the jaws approach full open, they push the sleeve to disengage the lugs. A spline coupler restrains sleeve rotation but can be omitted. This chuck construction can mount directly onto standard threaded splindles of existing tools.

Chuck mount

An axially movable sleeve has interference members or lugs engageable with interference members or lugs associated with the split nut in a chuck. When the chuck is driven by the spindle, the axially movable interference members engage the split nut interference members and are restrained from rotation. The nut is also restrained and the chuck jaws open or close depending upon the direction of rotation of the chuck body. The sleeve is positioned to be engaged by the jaws as they approach full open position. The jaws then move the sleeve axially to disengage the interference members and stop further opening of the jaws before they reach a position to wedge or jam in the open position.

Self disengaging keyless chuck

A push-on/quick release locking arrangement is mounted on a socket wrench extension or driver having a cylindrical body with a square drive end. An inclined transverse bore in the drive end intersects opposed flat faces of the drive end and lock balls are mounted in the bore for movement between a 'lock' position and a 'release' position. In the 'lock' position one ball projects from the end of the bore nearest the end of the drive end to engage a cooperating cavity in the drive recess of a socket. In the 'release' position the balls lie within the cross section of the drive end. There is an axial groove in the flat face intersected by the end of said bore further from the end of the drive end. A cylindrical grip sleeve is mounted for slideable movement on the cylindrical body of the extension. The end of said sleeve remote from the drive end is turned inwardly and an integral control tab projects from the other end of the sleeve. A spring is captured inside the sleeve between the inturned end and an inside shoulder formed in the sleeve. A coil of the spring is captured in a groove in the cylindrical body so the spring bears against the sleeve to bias the sleeve towards the drive end and the tab projecting from the sleeve fits into the axial groove and overlies the lock ball when the inturned end of the sleeve abuts the spring coil.

Socket wrench extension

The power tool has a magnetic base with superposed permanent magnet assemblies. The upper assembly can be moved relative to the lower assembly to subtract from or reinforce the magnetic field. When the sensing probe is pushed into the base the electric motor can be switched on to rotate a spindle on which a rotary cutting tool is axially mounted. The tool feed is controlled by a handle which can be mounted on either side of the tool housing. A coolant reservoir on the base has a hose connected to a pump which is connected to a manifold supplying coolant to the center of the cutting tool. The cutting tool is biased upwardly and pinches off the coolant when the tool is raised from the work. The tubular tool shank is retained on the drive spindle by balls carried by a cage and moved into engagement with a groove in the tool shank by a cam surface on a release collar spring biased to move the balls to engage the tool.

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Brookfield, WI, United States of America

Bernhard Palm