Patent US3828865A successfully refreshed from Google Patents.
US3828865A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hammer drill
Assignee: Metabowerke GmbH and Co
•
Filing: 1970-07-29
•
Granted: 1974-08-13
•
Expires: 1990-07-29
Abstract
Abstract A percussion or hammer drill with a gear unit which is preferably driven by an electric motor and permits the ratio between the speed of rotation of the drilling tool and the frequency of the impacts of the striker upon this tool to be varied.
Inventors
- 👤 A Schnizler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:06
CPC Classifications
B; B25; B25D; B25D16/00; B25D16/006; B25D2211/00; B25D2211/003; B25D2250/00; B25D2250/195; B25D2250/201
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
292 words
A hammer drill comprising a housing; tool holding means rotatably mounted at least partly in said housing for holding a drilling tool; striking means mounted in said housing for reciprocating movement in the diRection of the axis of said tool and adapted to intermittently exert impacts at least indirectly upon said tool so as to move the same in axial direction relative to said housing; a gear unit in said housing; means for driving said gear unit and comprising a driven shaft and a drive pinion secured to said driven shaft, said gear unit comprising first gear means comprising a first shaft rotatably mounted in said housing, a gear secured to said first shaft and engaging with said drive pinion and having a crank pin on one side thereof connected to said striking means for reciprocating the same in said axial direction, said gear unit further comprising second gear means comprising a plurality of gears of different size secured to said first shaft, a second shaft rotatably mounted in said housing, a plurality of gears on said second shaft, normally freely rotatable thereon and respectively meshing with associated gears on said first shaft, and transmission means for transmitting the rotation of said second shaft to said tool holding means; and control means for varying the speed of rotation of said tool holding means and thereby the ratio between said speed of rotation and the impacts of said striking means, said control means comprising movable connecting means within said housing for selectively connecting one or another of said gears on said second shaft so as to be rotatable therewith, and means adapted to be operated on the outer side of said housing for controlling the movements of said connecting means in said housing.
Claim 2
Dependent Claim
292 words
A hammer drill comprising a housing; tool holding means rotatably mounted at least partly in said housing for holding a drilling tool; striking means mounted in said housing for reciprocating movement in the diRection of the axis of said tool and adapted to intermittently exert impacts at least indirectly upon said tool so as to move the same in axial direction relative to said housing; a gear unit in said housing; means for driving said gear unit and comprising a driven shaft and a drive pinion secured to said driven shaft, said gear unit comprising first gear means comprising a first shaft rotatably mounted in said housing, a gear secured to said first shaft and engaging with said drive pinion and having a crank pin on one side thereof connected to said striking means for reciprocating the same in said axial direction, said gear unit further comprising second gear means comprising a plurality of gears of different size secured to said first shaft, a second shaft rotatably mounted in said housing, a plurality of gears on said second shaft, normally freely rotatable thereon and respectively meshing with associated gears on said first shaft, and transmission means for transmitting the rotation of said second shaft to said tool holding means; and control means for varying the speed of rotation of said tool holding means and thereby the ratio between said speed of rotation and the impacts of said striking means, said control means comprising movable connecting means within said housing for selectively connecting one or another of said gears on said second shaft so as to be rotatable therewith, and means adapted to be operated on the outer side of said housing for controlling the movements of said connecting means in said housing.
Claim 3
Dependent Claim
69 words
A hammer drill as defined in claim 1, in which said striking means comprise a cylinder, an air-cushioned piston within said cylinder having a striker rod secured to said piston and projecting from said cylinder, guide means for guiding said cylinder so as to be movable in said axial direction, and bearing means on said cylinder for receiving said crankpin and for operatively connecting the same to said cylinder.
Claim 4
Dependent Claim
87 words
A hammer drill as defined in claim 2, in which said guide means comprise a tubular member in which said cylinder is slidable in said axial direction, and bearing means for mounting said tubular member within said housing so as to be rotatable about an axis extending substantially parallel to said axial direction, said transmitting means comprising a bevel pinion on one end of said second shaft and a rim of bevel teeth on the upper end of said tubular member and meshing with said bevel pinion.
Claim 5
Dependent Claim
54 words
A hammer drill as defined in claim 3, in which said tool holding means is secured to the lower end of said tubular member and said tool is slidable in said axial direction within but nonrotatable relative to said tubular member and its upper end is adapted to be struck by said striker rod.
Claim 6
Dependent Claim
100 words
A hammer drill as defined in claim 2, in which said cylinder has a bushing secured to its end facing said tool, said striker being slidable substantially air-tight along said bushing, and a cover removably secured to and tightly closing the other end of said cylinder so that an air cushion is formed at both sides of said piston within said cylinder, said cover having a lateral extension on its outer side and a short oblong recess in said extension, and a needle bearing for said crankpin slidable within said recess during the rotation of said gear carrying said crankpin.
Claim 7
Dependent Claim
279 words
A hammer drill as defined in claim 1, in which each of said gears on said second shaft has a central bore through which said second shaft extends so as normally to be freely rotatable therein, the wall of said second shaft having diametrically opposite longitudinal slots therein and the wall of each of said bores having diametrically opposite grooves therein, said second shaft being at least partly tubular, said control means comprising a control rod axially slidable within said second shaft, a pin extending transversely through said control rod and having ends projecting therefrom through said longitudinal slots in the wall of said shaft into said grooves of a first of said gears On said second shaft so as to lock said first gear to said second shaft to drive the same while the adjacent gear on said second shaft continues to be freely rotatable on said second shaft, a compression spring within said second shaft acting upon one end of said control rod and tending to shift said rod within said second shaft so that said pin slides out of said grooves of said first gear and into said grooves of the adjacent gear so that said second shaft will then be driven by said adjacent gear while said first gear is freely rotatable, and means engaging upon the other end of said control rod against the action of said spring and manually movable on the outside of said housing for shifting said rod with said transverse pin from the grooves in one of said gears to the adjacent gear on said second shaft and for thus changing the speed of rotation of said tool holding means.
Claim 8
Dependent Claim
110 words
A hammer drill as defined in claim 6, in which said gears on said second shaft are located closely adjacent to each other, said bore of each of said gears having an annularly enlarged end adjacent to the corresponding annularly enlarged end of the bore of the adjacent gear whereby, when said control rod is shifted so that said transverse pin slides out of said grooves in one of said gears on said second shaft in the direction toward said grooves of the adjacent gear, said pin enters said enlarged parts of said bores of said adjacent gears and said adjacent gears are therefore freely rotatable on said second shaft.
Claim 9
Dependent Claim
51 words
A hammer drill as defined in claim 6, in which said manually movable means comprise a curved cam member within said housing engaging upon said other end of said control rod, and a control knob on the outside of said housing and connected to said cam member for moving the same.
Claim 10
Dependent Claim
62 words
A hammer drill as defined in claim 8, in which said cam member is substantially cup-shaped and has a central pin projecting from the bottom thereof through a bore in the wall of said housing, said control knob being connected to the outer end of said central pin, the peripheral wall of said cam member gradually varying in height from said bottom.
Claim 11
Dependent Claim
78 words
A hammer drill as defined in claim 9, in which the part of the wall of said housing covered by said knob has a plurality of recesses spaced from each other and each associated with one of said gears on said second shaft, and resilient means in said knob adapted to engage into either of said recesses when said knob is turned accordingly so as to lock said cam member and said control rod in the adjusted position.
Claim 12
Dependent Claim
222 words
A hammer drill comprising a housing; tool holding means rotatably mounted in said housing for holding a drilling tool; striking means mounted in said housing reciprocatable in the direction of the axis of said tool and adapted to intermittently exert impacts at least indirectly upon said tool so as to move the same in said axial direction relative to said housing; a motion-transmitting unit in said housing; means for driving said motion-transmitting unit, said motion-transmitting unit comprising first motion-transmitting means for reciprocating said striking means in said direction and second motion-transmitting means for rotating said tool holding means about said axis and comprising a coupling shaft in permanent driving engagement with said tool holding means, first and second gears permanently coupled with said drive means, and coupling means shiftable between a first end position connecting one of said gears to said coupling shaft for driving the latter at a first speed and a second end position connecting the other of said gears to said coupling shaft for driving the latter at a second speed; and control means cooperating with said coupling means for shifting the same between said positions thereof so as to vary the speed of rotation of the tool holding means and thereby the ratio between the speed of rotation and the frequency of the impacts of said striking means.
Claim 13
Dependent Claim
222 words
A hammer drill comprising a housing; tool holding means rotatably mounted in said housing for holding a drilling tool; striking means mounted in said housing reciprocatable in the direction of the axis of said tool and adapted to intermittently exert impacts at least indirectly upon said tool so as to move the same in said axial direction relative to said housing; a motion-transmitting unit in said housing; means for driving said motion-transmitting unit, said motion-transmitting unit comprising first motion-transmitting means for reciprocating said striking means in said direction and second motion-transmitting means for rotating said tool holding means about said axis and comprising a coupling shaft in permanent driving engagement with said tool holding means, first and second gears permanently coupled with said drive means, and coupling means shiftable between a first end position connecting one of said gears to said coupling shaft for driving the latter at a first speed and a second end position connecting the other of said gears to said coupling shaft for driving the latter at a second speed; and control means cooperating with said coupling means for shifting the same between said positions thereof so as to vary the speed of rotation of the tool holding means and thereby the ratio between the speed of rotation and the frequency of the impacts of said striking means.
Claim 14
Dependent Claim
40 words
A hammer drill as defined in claim 11, wherein said coupling Means is shiftable by the control means also to an intermediate position between said two end positions in which neither of said gears is connected to said coupling shaft.
Claim 15
Dependent Claim
123 words
A hammer drill comprising a housing; tool holding means rotatably mounted in said housing for holding a drilling tool; striking means mounted in said housing for reciprocating movement in the direction of the axis of said tool and adapted to intermittently exert impacts at least indirectly on said tool; gear means in said housing for rotating said tool holding means at variable speeds, said gear means including a first shaft rotatably mounted in said housing; a driven shaft rotatably mounted in said housing; a pinion fixed to said driven shaft; a gear fixed to said first shaft and meshing with said pinion; and a crank pin on said gear and connected to said striking means for reciprocating the same in said axial direction.
Claim 16
Dependent Claim
123 words
A hammer drill comprising a housing; tool holding means rotatably mounted in said housing for holding a drilling tool; striking means mounted in said housing for reciprocating movement in the direction of the axis of said tool and adapted to intermittently exert impacts at least indirectly on said tool; gear means in said housing for rotating said tool holding means at variable speeds, said gear means including a first shaft rotatably mounted in said housing; a driven shaft rotatably mounted in said housing; a pinion fixed to said driven shaft; a gear fixed to said first shaft and meshing with said pinion; and a crank pin on said gear and connected to said striking means for reciprocating the same in said axial direction.
Claim 17
Dependent Claim
94 words
A hammer drill as defined in claim 13, wherein said gear means further comprises at least two additional gears of different diameters mounted on said first shaft for rotation therewith, a second shaft rotatably mounted in said housing, at least two further gears normally freely rotatable on said second shaft and respectively meshing with said gears on said first shaft, and operator controlled coupling means for selectively coupling any of said further gears to said second shaft for rotation therewith; and including a drive connection between said second shaft and said tool holding means.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| 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 |