US3828863A — Combined portable electric impact wrench and chip…

Claim 1

Independent Claim 231 words

A portable power tool, particularly a combined electric impact wrench and chipping hammer, comprising a housing; a prime mover mounted in said housing and having a rotary output member; a tool holder rotatably and axially movably mounted in said housing; impeller means mounted in said housing and actuatable to transmit to said tool holder recurring axial impulses; first transmission means mounted in said housing and having an input element receiving torque from said output member, a mobile output element for actuating said impeller means, and clutch means for moving said output element in response to rotation of said input element; first control means for disengaging said clutch means at the will of the operator; multispeed second transmission means mounted in said housing between said tool holder and said output member and having a plurality of different speed ratios and a neutral position; and second control means actuatable independently of said first control means to select the speed ratio or the neutral position of said second transmission means so that said tool holder is movable axially by said impeller means while said second transmission means is in said neutral position or drives said tool holder at a selected speed, and that said output element of said first transmission means is idle while said second transmission means rotates said tool holder at a selected speed. rotates said tool holder at a selected speed.

Claim 2

Dependent Claim 231 words

A portable power tool, particularly a combined electric impact wrench and chipping hammer, comprising a housing; a prime mover mounted in said housing and having a rotary output member; a tool holder rotatably and axially movably mounted in said housing; impeller means mounted in said housing and actuatable to transmit to said tool holder recurring axial impulses; first transmission means mounted in said housing and having an input element receiving torque from said output member, a mobile output element for actuating said impeller means, and clutch means for moving said output element in response to rotation of said input element; first control means for disengaging said clutch means at the will of the operator; multispeed second transmission means mounted in said housing between said tool holder and said output member and having a plurality of different speed ratios and a neutral position; and second control means actuatable independently of said first control means to select the speed ratio or the neutral position of said second transmission means so that said tool holder is movable axially by said impeller means while said second transmission means is in said neutral position or drives said tool holder at a selected speed, and that said output element of said first transmission means is idle while said second transmission means rotates said tool holder at a selected speed. rotates said tool holder at a selected speed.

Claim 3

Dependent Claim 54 words

A power tool as defined in claim 1, wherein said impeller means comprises a pneumatic cylinder and piston unit including a cylinder which is reciprocable by said output element of said first transmission means and a piston which is reciprocable in said cylinder and is arranged to impart said impulses to said tool holder.

Claim 4

Dependent Claim 17 words

A power tool as defined in claim 1, wherein said second transmission means comprises a two-speed transmission.

Claim 5

Dependent Claim 45 words

A power tool as defined in claim 1, further comprising a safety clutch installed between said second transmission means and said tool holder and arranged to disconnect said tool holder from said second transmission means when said tool holder offers a predetermined resistance to rotation.

Claim 6

Dependent Claim 24 words

A power tool as defined in claim 1, wherein said prime mover comprises an electric motor and said clutch means comprises a positive clutch.

Claim 7

Dependent Claim 132 words

A power tool as defined in claim 5, wherein said positive clutch comprises a hollow shaft arranged to transmit torque to said output element and having at least one opening, a torque transmitting element provided in said opening and movable between a first position in which it partly extends from said hollow shaft and is driven by said input element and a second position in the interior of said hollow shaft, and a displacing member movable in said shaft axially between an operative positIon in which said displacing member maintains said torque transmitting element in said first position and an inoperative position in which said torque transmitting element is free to assume said second position, said first control means being arranged to move said displacing member between said operative and inoperative positions.

Claim 8

Dependent Claim 71 words

A power tool as defined in claim 6, wherein said torque transmitting element is a sphere and said input element includes a gear having an internal recess which receives a portion of said sphere in said first position of said sphere, said displacing member comprising a bolt having a groove which receives a portion of said sphere in said second position of said sphere when said bolt assumes said inoperative position.

Claim 9

Dependent Claim 53 words

A power tool as defined in claim 7, wherein said positive clutch further comprises biasing means or permanently urging said bolt to one of said positions thereof and said first control means comprises an eccentric actuatable to move said bolt to the other of said positions against the opposition of said biasing means.

Claim 10

Dependent Claim 78 words

A power tool as defined in claim 5, wherein said positive clutch comprises a first annulus of claws driven by said input element and a second annulus of complementary claws arranged to move said output element, said first control means comprising means for moving one of said annuli of claws toward and away from the other annulus to thereby place the claws of said first annulus into and out of mesh with the claws of said second annulus.

Claim 11

Dependent Claim 81 words

A power tool as defined in claim 9, wherein said input element comprises a first gear which receives torque from said prime mover and said output element comprises or is movable by a second gear which is coaxial with said first gear one of said gears being movable axially toward and away from the other of said gears and said first and second annuli of claws being respectively provided on said first and second gears and being located between said gears.

Claim 12

Dependent Claim 123 words

A power tool as defined in claim 5, wherein said positive clutch comprises a shaft which is arranged to drive said output element, a gear rotatably mounted on said shaft and receiving torque from said output member of said prime mover, a clutch element rotatable with and movable axially of said shaft toward and away from said gear, a first annulus of claws provided on said gear and facing said clutch element, and a second annulus of complementary claws provided on said clutch element and facing said gear, said first control means comprising means for moving said clutch element toward and away from said gear to thereby move said second annulus of claws into and from mesh with said first annulus of claws.

Claim 13

Dependent Claim 114 words

A power tool as defined in claim 1, wherein said second transmission means comprises a two-speed transmission including an intermediate shaft driven by said output member of said prime mover, a second shaft arranged to transmit torque to said tool holder, coaxial first and second gears rotatably mounted on said second shaft and being driven by said intermediate shaft at different speeds and respectively having first and second torque transmitting portions, and torque receiving means provided on said second shaft, said gears being movable axially of said second shaft and said second control means comprising shifter means actuatable to move said first or second torque transmitting portion into engagement with said torque receiving means.

Claim 14

Dependent Claim 30 words

A power tool as defined in claim 12, wherein said second control means further comprises a manually operable eccentric for moving said gears axially by way of said shifter means.

Claim 15

Dependent Claim 60 words

A power tool as defined in claim 13, wherein said second control means further comprises resilient means interposed between said eccentric and said shifter means so that said shifter means can move said gears axially when one of said first and second torque transmitting portions is ready to move into engagement with said torque receiving means of said second shaft.

Claim 16

Dependent Claim 155 words

A power tool as defined in claim 1, wherein said second transmission means comprises a two-speed transmission including a first shaft driven by said output member of said prime mover, a second shaft arranged to drive said tool holder, a sleeve-like shifter movable axially of and rotatable with said second shaft, first and second gears driven by said first shaft at different speeds and surrounding said shifter, first and second torque transmitting portions respectively provided on said first and second gears, and torque receiving means provided on said shifter, said second control means comprising means for moving said shifter axially between a first position in which said torque receiving means receives torque from said first torque transmitting portion, a second portion in which said torque receiving means receives torque from said second torque transmitting portion, and a third portion in which said torque receiving means is disengaged from said first and second torque transmitting portions.

Claim 17

Dependent Claim 27 words

A power tool as defined in claim 15, wherein said second control means comprises a manually operable eccentric for moving said shifter axially of said second shaft.

Claim 18

Dependent Claim 48 words

A power tool as defined in claim 16, wherein said second control means further comprises resilient means interposed between said shifter and said eccentric so that said shifter can move axially when said motion receiving means thereof registers with one of said first and second troque transmitting portions.

Claim 19

Dependent Claim 20 words

A power tool as defined in claim 1, further comprising blocking means actuatable to prevent rotation of said tool holder.

Claim 20

Dependent Claim 59 words

A power tool as defined in claim 18, further comprising a sleeve rotatable with said tool holder and having at least one external axially parallel groove, said blocking means comprising a shaft rotatable by hand and having a projection movable into and from said groove, the axis of said shaft being inclined relative to the axis of said sleeve.

Claim 21

Dependent Claim 88 words

A power tool as defined in claim 1, further comprising a safety clutch installed between said second transmission means and said tool holder and arranged to disconnect said tool holder from said second transmission means when said tool holder offers a predetermined resistance to rotation, said safety clutch comprising at least one torque transmitting element movable between an operative position in which said second transmission means trasmits torque to said tool holder and an inoperative position in which said tool holder is disconnected from said second transmission means.

Claim 22

Dependent Claim 137 words

A power tool as defined in claim 20, wherein said safety clutch further comprises a sleeve arranged to rotate said tool holder and having a flute which normally receives a first portion of said torque transmitting element in said operative position thereof, said second transmission comprising a hollow shaft surrounding said flute and having a radial opening receiving a second portion of said torque transmitting element in said operative position thereof, said safety clutch further comprising a pressure transmitting member arranged to yieldably urge said torque transmitting element to said operative position and to permit said torque transmitting element to move to said inoperative position, in which latter position said first portion of said torque transmitting element is received in said opening, in response to said predetermined resistance of said tool holder to rotation with said shaft.

Claim 23

Dependent Claim 68 words

A power tool as defined in claim 21, wherein said pressure transmitting member is a ring which surrounds and is axially movable on said hollow shaft, said torque transmitting element having a third portion which extends radially beyond said opening and is in abutment with said ring in said operative position thereof, said safety clutch further comprising resilient means for biasing said ring against said torque transmitting element.

Claim 24

Dependent Claim 32 words

A power tool as defined in claim 22, wherein said ring has at least one outwardly flaring conical surface which is engagEd by said torque transmitting element in said operative position thereof.

Claim 25

Dependent Claim 76 words

A power tool as defined in claim 22, wherein said pressure ring has a first radially outwardly flaring conical surface which contacts said torque transmitting element in said operative position thereof and a second radially outwardly flaring conical surface which is engaged by said torque transmitting element in said inoperative position thereof, said first and second conical surfaces respectively making with the axis of said hollow shaft a relatively small and a relatively large acute angle.

Claim 26

Dependent Claim 16 words

A power tool as defined in claim 22, wherein said torque transmitting element is a sphere.

Claim 27

Dependent Claim 16 words

A power tool as defined in claim 22, wherein said torque transmitting element is a roller.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1977-08-12	1978-02-11	1978-08-13	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1981-08-12	1982-02-11	1982-08-13	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1985-08-12	1986-02-11	1986-08-13	$7700.00	Window Closed / Lapsed

Combined portable electric impact wrench and chipping hammer

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