Power driven device

Claim 2

A power driven device, comprising: a casing; an impact imparting mechanism; means mounting said impact imparting mechanism in said casing; a motor; motion transmitting and converting means drive-connecting said motor to said impact imparting mechanism for cycling said mechanism through working and return strokes; a rotatably mounted tool holder; and means so drive-connecting said impact imparting mechanism to said tool holder that said mechanism rotatably advances said tool holder during one of the strokes in each cycle thereof but does not effect rotation of the tool holder in the other stroke of each cycle thereof, said drive connecting means including a unidirectionally acting rotatable drive means having an input member and an output member with the output member being operatively connected to said tool holder and a frictional drive connection providing means capable of transmitting only forces up to a selected maximum magnitude operatively connected between said impact imparting mechanism and the input member of said unidirectionally acting drive means, whereby the drive connection between the impact imparting mechanism and the tool holder is effectively interrupted while there is a rotation restraining force on said tool holder which exceeds the magnitude of the force which said frictional drive connection is capable of transmitting.

Claim 3

The power driven device of claim 1, wherein the means drive-connecting the impact imparting mechanism to the tool holder includes a rotatably mounted driven member connected to said tool holder for rotation therewith, said tool holder being axially movable relative to said driven member; a rotatably mounted drive member axially aligned with said driven member; and first and second means so drive-connecting said impact imparting mechanism to said drive member through said frictional drive connection and said drive member to said driven member that, during one of said working and return strokes in each cycle of said impact imparting mechanism, the rectilinear movement of said mechanism causes a rotary advance of said drive member and said drive member rotatably advances said driven member and therefore said tool holder.

Claim 4

The power driven device of claim 2, wherein said imparting mechanism includes a rectilinearly reciprocable piston; said drive member has a bore therein into which said piston extends; and the means drive-connecting the impact imparting mechanism to said drive member comprises external helical splines on said piston and internal helical splines in the bore of said drive member.

Claim 5

The power driven device of claim 1, wherein said impact imparting mechanism comprises a cylindrical piston having one cLosed end and a driver slidable in said piston and extending through the other end of the piston, said driver being engageable with said tool holder and said piston being so ported as to permit the formation of air cushions in the opposite ends of said piston as said driver moves back and forth therein.

Claim 6

The power driven device of claim 4, wherein the motion transmitting and converting means drive-connecting said motor to said impact imparting mechanism comprises means for reciprocating the piston of the impact imparting mechanism which includes a rotatably mounted crank having an eccentric crankpin thereon; a connecting rod pivotally fixed to said crankpin; means pivotally fixing said connecting rod to said piston; and means drive-connecting said motor to said rotatably mounted crank.

Claim 7

The power driven device of claim 5, wherein said motor has an output shaft and wherein the means drive-connecting the motor output shaft to said crank is gear teeth on said shaft and gear teeth around the periphery of said crank intermeshing with those on the motor output shaft.

Claim 8

The power driven device of claim 4, wherein the motion transmitting and converting means drive-connecting the motor to the impact imparting mechanism comprises means for reciprocating the piston of the impact imparting mechanism and wherein said piston reciprocating means includes a rotatably mounted crank; an eccentrically mounted crankpin; a crosshead having a slot extending at right angles to the direction of reciprocating of said piston, said crankpin extending into said slot; guides confining said crosshead to rectilinear, reciprocal movement in the same direction as said piston; and means fixing said crosshead to said piston.

Claim 9

The power driven device of claim 7, wherein said casing has means for retaining the tool holder therein and an opening in the nose end thereof through which a tool can be inserted for connection to said tool holder, said tool holder having a blind tool receiving bore therein with the closed end of the bore being the furtherest from the nose end of the casing, and there being a sealing member extending completely around and engaging the periphery of the tool holder and the inside of the casing, whereby foreign matter is prevented from penetrating beyond the work holder into the interior of the casing.

Claim 10

A power driven device according to claim 8, wherein the opening in the nose end of the casing has a noncircular configuration, whereby said casing will restrain against rotation a tool inserted therethrough which has a matching external configuration.

Claim 11

The device of claim 9, wherein the tool receiving bore in the tool holder has a noncircular configuration, whereby a tool inserted into said bore and having a matching external configuration is connected to said tool holder for rotation therewith.

Claim 12

The power driven device of claim 1, wherein the means drive-connecting the impact imparting mechanism to the tool holder comprises ratchet means including axially aligned, rotatable input member and output members; means connecting said output member to said tool holder for rotation therewith; and means rotating said input member back and forth as said impact imparting mechanism moves in opposite directions, there being cooperating first and second means on said input and output members engageable when said input member is rotated in one direction only to rotatably advance said output member and said tool holder.

Claim 13

A power driven device, comprising: a tool holder; a rectilinearly reciprocable impact imparting mechanism having a working stroke in which it axially impacts said tool holder and a return stroke; a first rotatably driven member, said tool holder being fixed to said first driven member for rotation therewith; a rotatable driving member disposed between said first driven member and said impact imparting mechanism, there being cooperating means on said impact imparting mechanism and said driving member for converting the rectilinear movement oF said impact imparting mechanism during its working and return strokes into alternately oppositely directed rotary movements of said driving member; a rotary motion transmitting component fixed to said driving member for rotation therewith; a second driven member; means frictionally drive-connecting said second driven member to said rotary motion transmitting component; means on said second driven member engageable with cooperating means on said first driven member to rotatably advance said first driven member and therefore said tool holder as said driving member is rotated in one of said opposite directions, said means being constructed to permit the driving member to rotate relative to the driven member as it rotates in the other of said opposite directions; and means biasing into engagement the cooperating means on said first and second driven members.

Claim 14

A power driven device, comprising: a tool holder; a rectilinearly reciprocable impact imparting mechanism having a working stroke in which it axially impacts said tool holder and a return stroke; a first rotatably driven member, said tool holder being fixed to said first driven member for rotation therewith; a rotatable driving member disposed between said first driven member and said impact imparting mechanism, there being cooperating means on said impact imparting mechanism and said driving member for converting the rectilinear movement oF said impact imparting mechanism during its working and return strokes into alternately oppositely directed rotary movements of said driving member; a rotary motion transmitting component fixed to said driving member for rotation therewith; a second driven member; means frictionally drive-connecting said second driven member to said rotary motion transmitting component; means on said second driven member engageable with cooperating means on said first driven member to rotatably advance said first driven member and therefore said tool holder as said driving member is rotated in one of said opposite directions, said means being constructed to permit the driving member to rotate relative to the driven member as it rotates in the other of said opposite directions; and means biasing into engagement the cooperating means on said first and second driven members.

Claim 15

A power driven device, comprising: a casing; a tool holder rotatably supported by said casing; an impact imparting mechanism comprising a cylindrical piston having one closed end and a driver slidable in said piston and extending through the other end of the piston, said driver being engageable with said tool holder and said piston being so ported as to permit the formation of air cushions in the opposite ends of said piston as said driver moves back and forth therein; means mounting said impact imparting mechanism for reciprocable rectilinear movement in said casing; a motor; motion transmitting and converting means drive-connecting said motor to said impact imparting mechanism for cycling said mechanism through oppositely directed working and return strokes, said last-mentioned means comprising means for reciprocating the piston of the impact imparting mechanism and said piston reciprocating means including a wobble plate operatively connected to said piston; and means so drive-connecting said impact imparting mechanism to said tool holder that, during one of the strokes in each cycle thereof, said mechanism rotatably advances said tool holder, said mechanism not effecting rotation of the tool holder in the other stroke of each cycle thereof, and said drive-connecting means including a frictional drive connection capable of transmitting only forces up to a selected maximum magnitude, whereby the drive connection between the impact imparting mechanism and the tool holder is effectively interrupted while there is a rotation restraining force on said tool holder which exceeds the magnitude of the force which said frictional drive connection is capable of transmitting.

Claim 16

A power driven device, comprising: a casing; a tool holder rotatably supported by said casing; an impact imparting mechanism comprising a cylindrical piston having one closed end and a driver slidable in said piston and extending through the other end of the piston, said driver being engageable with said tool holder and said piston being so ported as to permit the formation of air cushions in the opposite ends of said piston as said driver moves back and forth therein; means mounting said impact imparting mechanism for reciprocable rectilinear movement in said casing; a motor; motion transmitting and converting means drive-connecting said motor to said impact imparting mechanism for cycling said mechanism through oppositely directed working and return strokes, said last-mentioned means comprising means for reciprocating the piston of the impact imparting mechanism and said piston reciprocating means including a wobble plate operatively connected to said piston; and means so drive-connecting said impact imparting mechanism to said tool holder that, during one of the strokes in each cycle thereof, said mechanism rotatably advances said tool holder, said mechanism not effecting rotation of the tool holder in the other stroke of each cycle thereof, and said drive-connecting means including a frictional drive connection capable of transmitting only forces up to a selected maximum magnitude, whereby the drive connection between the impact imparting mechanism and the tool holder is effectively interrupted while there is a rotation restraining force on said tool holder which exceeds the magnitude of the force which said frictional drive connection is capable of transmitting.

Claim 17

A power driven device, comprising: a tool holder; a rectilinearly reciprocable impact imparting mechanism having a working stroke in which it axially impacts said tool holder and a return stroke; a first rotatably driven member, said tool holder being fixed to said first driven member for rotation therewith; a rotatable driving member disposed between said first driven member and said impact imparting mechanism, there being cooperating means on said impact imparting mechanism and said driving member for converting the rectilinear movement of said impact imparting mechanism during its working and return strokes into alternately oppositely directed rotary movements of said driving member; a rotary motion transmitting component fixed to said driving member for rotation therewith, said rotary motion transmitting component being disposed in surrounding relationship to said driving member; a second driven member disposed in surrounding relationship to said driving member; means frictionally drive-connecting said second driven member to said rotary motion transmitting component which includes a component disposed between and frictionally engaging said rotary motion transmitting component and said second driven member; means on said second driven member engageable with cooperating means on said first driven member to rotatably advance said first driven member and therefore said tool holder as said driving member is rotated in one of said opposite directIons, said means being constructed to permit the driving member to rotate relative to the driven member as it rotates in the other of said opposite directions; and means biasing into engagement the cooperating means on said first and second driven members.

Claim 18

A power driven device, comprising: a tool holder; a rectilinearly reciprocable impact imparting mechanism having a working stroke in which it axially impacts said tool holder and a return stroke; a first rotatably driven member, said tool holder being fixed to said first driven member for rotation therewith; a rotatable driving member disposed between said first driven member and said impact imparting mechanism, there being cooperating means on said impact imparting mechanism and said driving member for converting the rectilinear movement of said impact imparting mechanism during its working and return strokes into alternately oppositely directed rotary movements of said driving member; a rotary motion transmitting component fixed to said driving member for rotation therewith, said rotary motion transmitting component being disposed in surrounding relationship to said driving member; a second driven member disposed in surrounding relationship to said driving member; means frictionally drive-connecting said second driven member to said rotary motion transmitting component which includes a component disposed between and frictionally engaging said rotary motion transmitting component and said second driven member; means on said second driven member engageable with cooperating means on said first driven member to rotatably advance said first driven member and therefore said tool holder as said driving member is rotated in one of said opposite directIons, said means being constructed to permit the driving member to rotate relative to the driven member as it rotates in the other of said opposite directions; and means biasing into engagement the cooperating means on said first and second driven members.

Claim 19

The power driven device of claim 14, wherein said driving member includes means limiting the movement of the second driven member in one direction and including means fixing the motion transmitting component to the driving member to thereby determine the maximum force transmitting capability of the component disposed between said rotary motion transmitting component and said second driven member.

Claim 20

The power driven device of claim 14, wherein the component frictionally engaging the rotary motion transmitting component and the second driven member comprises at least one Belleville washer.

Claim 21

The power driven device of claim 16, wherein there are cooperating threads on said driving member and said motion transmitting component, whereby said motion transmitting component may be displaced axially along said driving member to vary the bias on the Belleville washer(s) and thereby preselect the frictional drive force which the motion transmitting component is capable of transmitting to said second driven member.

Claim 22

The power driven device of claim 13, wherein the means biasing the cooperating means on said first and second driven engagement comprises a compression spring means disposed between said casing and said rotary motion transmitting means and biasing said motion transmitting means and said second driven member toward said first driven member.

Claim 23

A power driven device, comprising: a rotatably mounted tool holder; a rectilinearly reciprocable impact imparting mechanism; means for cycling said mechanism through a working stroke in which it imparts an axial impact to said tool holder and an oppositely directed return stroke; and a reciprocable to intermittent, unidirectional rotary motion converting mechanism including a friction type torque overload release drive-connected between said impact imparting mechanism and said tool holder for rotatably advancing said tool holder, said overload release including calibration means for presetting the torque at which interruption of the drive connection between the impact imparting mechanism and the tool holder will occur.

Claim 24

A power driven device, comprising: a rotatably mounted tool holder; a rectilinearly reciprocable impact imparting mechanism; means for cycling said mechanism through a working stroke in which it imparts an axial impact to said tool holder and an oppositely directed return stroke; and a reciprocable to intermittent, unidirectional rotary motion converting mechanism including a friction type torque overload release drive-connected between said impact imparting mechanism and said tool holder for rotatably advancing said tool holder, said overload release including calibration means for presetting the torque at which interruption of the drive connection between the impact imparting mechanism and the tool holder will occur.

Claim 25

A power driven device, comprising: an impact imparting mechanism; means for cycling said mechanism through an impact imparting working stroke and a return stroke; a rotatably mounted tool holder; and means drive-connecting said impact imparting mechanism to said tool holder which includes means so drive-connecting said impact imparting mechanism to said tool holder that said mechanism rotatably advances said tool holder during one of the strokes in each cycle thereof but does not effect rotation of the tool holder in the other stroke of each cycle thereof, said drive-connecting means including means having cooperating annular surfaces providing a frictional drive connection between said impact imparting mechanism and said tool holder which is capable of transmitting only forces up to a selected maximum magnitude, whereby the drive connection between the impact imparting mechanism and the tool holder is effectively interrupted while there is a rotation restraining force on said tool holder which exceeds the magnitude of the force which said frictional drive connection is capable of transmitting.

Claim 26

A power driven device, comprising: an impact imparting mechanism; means for cycling said mechanism through an impact imparting working stroke and a return stroke; a rotatably mounted tool holder; and means drive-connecting said impact imparting mechanism to said tool holder which includes means so drive-connecting said impact imparting mechanism to said tool holder that said mechanism rotatably advances said tool holder during one of the strokes in each cycle thereof but does not effect rotation of the tool holder in the other stroke of each cycle thereof, said drive-connecting means including means having cooperating annular surfaces providing a frictional drive connection between said impact imparting mechanism and said tool holder which is capable of transmitting only forces up to a selected maximum magnitude, whereby the drive connection between the impact imparting mechanism and the tool holder is effectively interrupted while there is a rotation restraining force on said tool holder which exceeds the magnitude of the force which said frictional drive connection is capable of transmitting.

Claim 27

A power driven device, comprising: an impact imparting mechanism; means for cycling said mechanism through an impact imparting working stroke and a return stroke; a rotatably mounted tool holder; and means drive-connecting said impact imparting mechanism to said tool holder which includes a first means so drive-connecting said impact imparting mechanism to said tool holder that said mechanism rotatably advances said tool holder during one of the strokes in each cycle thereof but does not effect rotation of the tool holder in the other stroke of each cycle thereof, said drive-connecting means including a second means providing a frictional drive connection between said impact imparting mechanism and said tool holder capable of transmitting only forces up to a selected maximum magnitude, whereby the drive connection between the impact imparting mechanism and the tool holder is effectively interrupted while there is a rotation restraining force on said tool holder which exceeds the magnitude of the force which said frictional drive connection is capable of transmitting.

Claim 28

A power driven device, comprising: an impact imparting mechanism; means for cycling said mechanism through an impact imparting working stroke and a return stroke; a rotatably mounted tool holder; and means drive-connecting said impact imparting mechanism to said tool holder which includes a first means so drive-connecting said impact imparting mechanism to said tool holder that said mechanism rotatably advances said tool holder during one of the strokes in each cycle thereof but does not effect rotation of the tool holder in the other stroke of each cycle thereof, said drive-connecting means including a second means providing a frictional drive connection between said impact imparting mechanism and said tool holder capable of transmitting only forces up to a selected maximum magnitude, whereby the drive connection between the impact imparting mechanism and the tool holder is effectively interrupted while there is a rotation restraining force on said tool holder which exceeds the magnitude of the force which said frictional drive connection is capable of transmitting.