Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D16/00—Portable percussive machines with superimposed rotation, the rotational movement of the output shaft of a motor being modified to generate axial impacts on the tool bit
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D16/00—Portable percussive machines with superimposed rotation, the rotational movement of the output shaft of a motor being modified to generate axial impacts on the tool bit
  • B25D16/006—Mode changers; Mechanisms connected thereto
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D17/00—Details of, or accessories for, portable power-driven percussive tools
  • B25D17/06—Hammer pistons; Anvils ; Guide-sleeves for pistons
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D2216/00—Details of portable percussive machines with superimposed rotation, the rotational movement of the output shaft of a motor being modified to generate axial impacts on the tool bit
  • B25D2216/0007—Details of percussion or rotation modes
  • B25D2216/0046—Preventing rotation

Definitions

• a rotary hammer with a pneumatic hammer mechanism which is equipped with a catching device for the reciprocating racket. Hook-shaped holding elements engage in a groove of the racket when the hammer drill is lifted off the rock. An arbitrary shutdown of the drum from the outside, e.g. for pure drilling, however, is not possible with this catching device.
• the spline toothing of the swash plate can be brought out of engagement with the drive toothing on a special intermediate shaft externally by flipping a lever, but this requires a great deal of design effort.
• the hammer drill according to the invention with the characterizing features of the main claim has the advantage that a substantial reduction in price is achieved by the simpler design of the impact switch. It can be used in any operating condition of the hammer drill the impact stop can be switched on and off without gear wear.
• the novel impact cut-off device can be installed in a space-saving manner in the area of the guide tube and can alternatively also be used if a conventional cut-off can not be implemented elsewhere, for example for reasons of space.
• both the automatic idle shutdown and the decommissioning of the striking mechanism for pure drilling operation are carried out by one and the same component. This also results in a more compact and lighter construction of the rotary hammer.
• Figure 1 * shows a partially cut side view
• Figure 2 shows the tool-side end of a rotary hammer according to the invention in longitudinal section according to another embodiment.
• the hammer mechanism 2, the tool holder 3 with the tool 4 and parts of the housing 5 are shown in FIG. 1 of a hammer drill 1.
• the striker 6 is located within a pot piston 7 which is surrounded by a guide tube 8, the front end of which faces the tool 4 has an inwardly directed collar 9 with teeth 10.
• the toothing 10 constantly engages in a toothing 11 of the firing pin 12 which receives the tool.
• the toothing 11 is flattened in the central region of the firing pin 12, so that a wide groove 13 is created. After the groove 13, the toothing 11 again has a thickening 14 on which one or more holding elements 15 designed here as pawls with their inward protruding middle part 16.
• the individual holding elements 15 are connected in a rotationally fixed manner to the firing pin 12 and thus also to the guide tube 8 by means of a perforated disc 17 with an internal toothing corresponding to the toothing 11 and fixed at their mutual distance from one another.
• the disc 17 also serves as a limitation for the damping element 18 with an O-ring 19 and as a stop for the outward projections
• a spring ring 21 is arranged on the outside around the holding elements 15 between the projections 20 and the collar 9 and presses the holding elements 15 inwards against the firing pin 12. Opposite the spring washer
• a second weaker spring ring 22 holds the holding elements 15 in contact with the spring ring 21.
• the holding elements 15 have inwardly directed projections 23 which rest in the groove 13 on the firing pin 12 when the hammer drill 1 is operated.
• hook-like extensions 25 directed toward the groove 24 of the racket 6 are attached.
• Radially arranged, prestressed springs 27 each act on the rear sections 26 of the individual holding elements 15 from the outside.
• the springs 27 are guided in bushings 28 which pass through the guide tube 8 and rest on a projection of the control ring 30 which is tapered in the inside diameter.
• This projection consists of teeth 29 running in the axial direction of the striking mechanism.
• the diameter of the spring 27 is larger than the tooth spacing of the teeth 29.
• the control ring 30 carries on its inside a further toothing 31 which is in engagement with an external toothing 32 of the guide tube 8.
• the contact surface 33 of the control ring 30 adjoins the external toothing 32. Between this and the toothing 29 there is a bevel 34.
• the control ring 30 On the circumference, the control ring 30 carries an annular groove 35 into which an eccentrically arranged pin 36 of a loading button 37 engages.
• On the front of the control ring 30 there is a further set of teeth 38 on the outside which can be inserted into a set of teeth 40 fixed to the housing tube 39.
• gearwheel 41 which is in gear connection with the motor (not shown) and has teeth 42 corresponding to the teeth 29 for the rotary operation.
• FIG. 1 shows the pure impact operation.
• the collar 30 must stand so that the springs 27 abut the teeth 29.
• the firing pin must be pushed far enough (by pressing the hammer against the rock) so that the middle parts 16 of the holding elements 15 rest against its thickening 14 and the projections 23 can slide in the groove 13.
• the rotary drive is switched off because the teeth 29 are not in engagement with the toothing 42.
• the rotary drive can be switched on by turning the actuating button 37, which causes the toothing 29 to partially engage the toothing 42 without the springs 27 already reaching the region of the bevel 34 of the adjusting ring 30.
• the bevel 34 slides over the springs 37 and presses them radially inwards. In the end position, they rest on the contact surface 33 of the adjusting ring 30.
• the holding elements 15 tilt with their extensions 25 inwards, engage in the groove 24 of the racket 6 and hold it. If the striker 6 is not yet in the area of influence of the holding elements at this point, it can press back slightly against the force of the springs 27 with its beveled tip during its forward movement. Then the holding elements close again immediately and hold the racket 6 firmly.
• the fourth position spindle lock
• the control ring 30 is pushed all the way forward, as a result of which the toothing 38 engages in the fixed toothing 40. In this position, impact operation with a rotationally locked tool is possible.
• the holding elements 15 are not only used to switch off the impact, but also serve for active idle control. As soon as the firing pin 12 is propelled far enough due to the lack of back pressure through the rock, the projections 23 come to rest on the thickening 14 and the middle parts 16 on the bevel 14 '. The spring washer 21 and, if necessary, the spring 27 then to be preloaded push the section 26 with the extensions 25 inwards and the racket is caught.
• FIG. 2 shows a somewhat simpler example of a blow-off device without a rotation stop.
• the striker 6 'with groove 24' is located in the pot piston 7 ', which is surrounded by the guide tube 8 " ' with collar 9 'and toothing 10'. The latter engages in a thickened part 50 of a firing pin 12 '
• the end piece 51 of the firing pin 12 'facing the racket 6' is tapered.
• the holding elements 15 ' have inwardly radially projecting contact surfaces 52 and tapered holding arms 53 with hook-like extensions 25'.
• the holding elements 15' are damped by a damping element 18 'against which the projections 20' rest.
• Springs 27 'rest on the holding arms 53 of the holding elements 15' and are held in openings 54 of the guide tube 8 'with a flanged edge.
• a sliding block 55 is inserted from the outside into the springs 27 ', the head 56 of which lies against the contact surface 57 of the control ring 30'.
• a bevel 58 and another recessed contact surface 59 adjoin this contact surface 57.
• the control ring 30 ' carries an annular groove 35' into which an eccentrically arranged pin 36 'of an actuating button 37' engages.
• the control ring 30 ' is in the position "stop" in FIG. it presses with its contact surface 57 against the sliding block 55 and the spring 27 '.
• the holding elements 15 are tilted inwards and the extensions 25 'engage in the groove 24' of the racket 6 ', engage behind a collar 61 at the front end of the racket 6' and thereby hold it in place.
• the springs 27 ' also enable the racket 6' to be subsequently clipped into the already closed holding elements 15 '.
• the percussion piston 12 actively controls the idle running of the hammer drill 1.
• the thickening 50 is displaced up to the spring ring 21', the holding elements 15 with the rear edge 60 tip onto the thinner end piece 51 and come in catch position.
• the holding elements 15 are tilted back.
• the idle control can of course also be dispensed with by continuously executing the firing pin 12 'with the same diameter.
• pot pistons 7, 7 'or cylinder pistons can be used in all of the exemplary embodiments.
• a correspondingly shaped tool shank, intermediate striker or the like can take over control directly.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Percussive Tools And Related Accessories (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6307564

Family Applications (1)

Country Status (5)

Cited By (10)

Families Citing this family (6)

Citations (4)

Family Cites Families (1)

• 1986
  • 1986-08-16 DE DE19863627869 patent/DE3627869A1/de not_active Withdrawn
• 1987
  • 1987-07-10 DE DE8787904493T patent/DE3768961D1/de not_active Expired - Lifetime
  • 1987-07-10 EP EP19870904493 patent/EP0318480B1/de not_active Expired - Lifetime
  • 1987-07-10 JP JP62504169A patent/JP2550124B2/ja not_active Expired - Lifetime
  • 1987-07-10 WO PCT/DE1987/000309 patent/WO1988001219A1/de active IP Right Grant
• 1988
  • 1988-04-16 KR KR1019880700404A patent/KR880701617A/ko not_active Application Discontinuation

Patent Citations (4)

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