Patent US3993145A successfully refreshed from Google Patents.
US3993145A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power tool
Assignee: Robert Bosch GmbH
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Filing: 1974-06-14
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Granted: 1976-11-23
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Expires: 1994-06-14
Abstract
Abstract A power tool, particularly a power screwdriver, has a housing which accommodates a drive, and a tool holder which is rotatably mounted in the housing, together with a rotatable component that is connected with the drive to be rotated by the same. A coupling arrangement is provided, including cooperating coupling portions on the rotatable component and the tool holder, for connecting the tool holder with the rotatable component in torque-transmitting relationship, and for terminating such transmission of torque when the value of the latter exceeds a predetermined level.
Inventors
- 👤 Bernard Findeli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:49
CPC Classifications
B; B25; B25B; B25B23/00; B25B23/14; B25B23/145
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
381 words
A power tool, particularly a power screw driver, wherein the transmission between a drive and a tool holder is automatically terminated when a predetermined torque is exceeded, comprising a housing accommodating a drive, said drive comprising an air motor and a valve connecting said air motor with a source of compressed air and being movable to open position against a biasing force; a tool holder rotatably mounted in said housing; a rotatable component permanently connected with said drive to be rotated by the same, said rotatable component being formed with a transverse bore accommodating a plurality of ball members, and with a longitudinal bore intersecting said transverse bore; and means including coupling means for connecting said tool holder with said rotatable component in torque transmitting relationship and for terminating the transmission when the torque exceeds a predetermined value, said coupling means including a plurality of spherical coupling elements mounted on said rotatable component at fixed circumferentially spaced locations for rotation with said component, a plurality of circumferentially spaced axial recesses formed in an axial end of said tool holder which faces said coupling elements, and said connecting means includng further biasing means urging said coupling elements into respective ones of said recesses, a rod which holds said valve in open position when said torque is below said predetermined value, said rod being axially movable in said longitudinal bore of said rotating component in response to said torque exceeding said predetermined value so that said biasing force can move said valve to said closed position, a member surrounding said rotatable component and being formed with a stepped bore having a portion of larger and a portion of smaller diameter, said member being slidable axially of said rotatable component against the action of said biasing means from a position in which said smaller diameter portion of said bore surrounds said transverse bore and urges said ball members inwardly of the latter to block sliding of said valve rod, to a position in which said large diameter portion of said bore surrounds said transverse bore and said valve rod displaces said ball members radially outwardly of said transverse bore so as to be slidable in said longitudinal bore, said spherical coupling elements constituting the only drive connection between said component and said tool holder.
Claim 2
Dependent Claim
381 words
A power tool, particularly a power screw driver, wherein the transmission between a drive and a tool holder is automatically terminated when a predetermined torque is exceeded, comprising a housing accommodating a drive, said drive comprising an air motor and a valve connecting said air motor with a source of compressed air and being movable to open position against a biasing force; a tool holder rotatably mounted in said housing; a rotatable component permanently connected with said drive to be rotated by the same, said rotatable component being formed with a transverse bore accommodating a plurality of ball members, and with a longitudinal bore intersecting said transverse bore; and means including coupling means for connecting said tool holder with said rotatable component in torque transmitting relationship and for terminating the transmission when the torque exceeds a predetermined value, said coupling means including a plurality of spherical coupling elements mounted on said rotatable component at fixed circumferentially spaced locations for rotation with said component, a plurality of circumferentially spaced axial recesses formed in an axial end of said tool holder which faces said coupling elements, and said connecting means includng further biasing means urging said coupling elements into respective ones of said recesses, a rod which holds said valve in open position when said torque is below said predetermined value, said rod being axially movable in said longitudinal bore of said rotating component in response to said torque exceeding said predetermined value so that said biasing force can move said valve to said closed position, a member surrounding said rotatable component and being formed with a stepped bore having a portion of larger and a portion of smaller diameter, said member being slidable axially of said rotatable component against the action of said biasing means from a position in which said smaller diameter portion of said bore surrounds said transverse bore and urges said ball members inwardly of the latter to block sliding of said valve rod, to a position in which said large diameter portion of said bore surrounds said transverse bore and said valve rod displaces said ball members radially outwardly of said transverse bore so as to be slidable in said longitudinal bore, said spherical coupling elements constituting the only drive connection between said component and said tool holder.
Claim 3
Dependent Claim
41 words
A power tool as defined in claim 1, wherein said rotatable component is a shaft formed in its outer circumferential surface with a plurality of circumferentially spaced axial grooves in each of which one of said coupling elements is partly received.
Claim 4
Dependent Claim
27 words
A power tool as defined in claim 1, wherein said member is a sleeve having an open end which faces and in part receives said tool holder.
Claim 5
Dependent Claim
29 words
A power tool as defined in claim 1, and further comprising spherical retaining members connecting said tool holder with said rotatable component against axial displacement relative to the same.
Claim 6
Dependent Claim
29 words
A power tool as defined in claim 1; and further comprising means for varying the biasing force exerted by said biasing means, and for thereby changing said predetermined value.
Claim 7
Dependent Claim
15 words
A power tool as defined in claim 1, wherein said biasing means comprises spring means.
Claim 8
Dependent Claim
363 words
A power tool, particularly a power screw driver, wherein the transmission of torque between a drive and a tool holder is automatically terminated when a predetermined torque is exceeded, comprising a housing accommodating a drive; a tool holder rotatably mounted in said housing; a rotatable component permanently connected with said drive to be rotated by the same, said rotatable component including a sleeve, a flange formed on said sleeve and being provided with a plurality of axial apertures, and a jack shaft connecting said sleeve with said drive; and means including coupling means for connecting said tool holder with said rotatable component in torque transmitting relationship, and for terminating the transmission when the torque exceeds a predetermined value, said coupling means including a plurality of spherical coupling elements respectively received in part in said axial apertures, said flange having an axial thickness which is smaller than the diameter of said coupling elements and said axial apertures penetrating said flange, a plurality of circumferentially spaced recesses formed in an axial end of said tool holder which faces said coupling elements, and biasing means urging said coupling elements into respective ones of said recesses, said spherical coupling elements constituting the only drive connection between said component and said tool holder, said means comprising further an annular plate surrounding said sleeve at an axial end of said flange which faces away from said axial recesses, said plate being pressed by said biasing means against said axial end of said flange, a plunger received and axially shiftable in said sleeve and having one portion provided with a cylindrical circumferential surface, and an axially adjacent portion provided with a conical circumferential surface, said sleeve being provided with a transverse bore, and spherical members which are received in said bore and which are located inwardly of the outer circumference of said sleeve when said one portion is located opposite said bore and located partially outwardly of said outer circumference of said sleeve when said axially adjacent portion is located opposite said bore, said annular plate having an inner annular recess into which said spherical elements enter when they are located partially outwardly of said outer circumference of said sleeve.
Claim 9
Dependent Claim
363 words
A power tool, particularly a power screw driver, wherein the transmission of torque between a drive and a tool holder is automatically terminated when a predetermined torque is exceeded, comprising a housing accommodating a drive; a tool holder rotatably mounted in said housing; a rotatable component permanently connected with said drive to be rotated by the same, said rotatable component including a sleeve, a flange formed on said sleeve and being provided with a plurality of axial apertures, and a jack shaft connecting said sleeve with said drive; and means including coupling means for connecting said tool holder with said rotatable component in torque transmitting relationship, and for terminating the transmission when the torque exceeds a predetermined value, said coupling means including a plurality of spherical coupling elements respectively received in part in said axial apertures, said flange having an axial thickness which is smaller than the diameter of said coupling elements and said axial apertures penetrating said flange, a plurality of circumferentially spaced recesses formed in an axial end of said tool holder which faces said coupling elements, and biasing means urging said coupling elements into respective ones of said recesses, said spherical coupling elements constituting the only drive connection between said component and said tool holder, said means comprising further an annular plate surrounding said sleeve at an axial end of said flange which faces away from said axial recesses, said plate being pressed by said biasing means against said axial end of said flange, a plunger received and axially shiftable in said sleeve and having one portion provided with a cylindrical circumferential surface, and an axially adjacent portion provided with a conical circumferential surface, said sleeve being provided with a transverse bore, and spherical members which are received in said bore and which are located inwardly of the outer circumference of said sleeve when said one portion is located opposite said bore and located partially outwardly of said outer circumference of said sleeve when said axially adjacent portion is located opposite said bore, said annular plate having an inner annular recess into which said spherical elements enter when they are located partially outwardly of said outer circumference of said sleeve.
Claim 10
Dependent Claim
72 words
A power tool as defined in claim 7, wherein said drive includes an air-motor and a valve movable between an open and a closed position for connecting said air-motor with and disconnecting it from a source of compressed air; and further comprising rod means operatively associated with said plunger and with said valve for moving the latter to said open position in response to shifting of said plunger in one axial direction.
Claim 11
Dependent Claim
18 words
A power tool as defined in claim 7, wherein said biasing spring comprises at least one dished spring.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-11-23 | 1980-05-24 | 1980-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-23 | 1984-05-24 | 1984-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-23 | 1988-05-24 | 1988-11-23 | $7700.00 | Window Closed / Lapsed |