US3841418A - Hammer drills - Google Patents

Hammer drills Download PDF

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Publication number
US3841418A
US3841418A US00315425A US31542572A US3841418A US 3841418 A US3841418 A US 3841418A US 00315425 A US00315425 A US 00315425A US 31542572 A US31542572 A US 31542572A US 3841418 A US3841418 A US 3841418A
Authority
US
United States
Prior art keywords
drive shaft
cam
striker member
ballistic
spindle
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00315425A
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English (en)
Inventor
H Biersack
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Impex Essen Vertrieb von Werkzeugen GmbH
Original Assignee
Impex Essen Vertrieb von Werkzeugen GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Impex Essen Vertrieb von Werkzeugen GmbH filed Critical Impex Essen Vertrieb von Werkzeugen GmbH
Application granted granted Critical
Publication of US3841418A publication Critical patent/US3841418A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25D—PERCUSSIVE TOOLS
    • B25D11/00—Portable percussive tools with electromotor or other motor drive
    • B25D11/005—Arrangements for adjusting the stroke of the impulse member or for stopping the impact action when the tool is lifted from the working surface
    • 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
    • B25D2211/00—Details of portable percussive tools with electromotor or other motor drive
    • B25D2211/06—Means for driving the impulse member
    • B25D2211/062—Cam-actuated impulse-driving mechanisms

Definitions

  • a hammer drill has a spindle for receiving the stem of a drilling tool.
  • the spindle is rotatably driven by a [52] US. Cl 173/109, 173/119, 173/124 drive shaft arranged parallel thereto and has a Striker [51] Int. Cl B2511 11/00 adapted to move into the spindle and Strike the p 1581 Fleld Search 173/13, 1514894 1091 ling tool disposed therein.
  • the striker is cyclically 173/117 123 withdrawn in opposition to a spring and released into striking engagement with the drilling tool disposed in [56] References C'ted the spindle by means of a ballistic cam mounted on UNITED STATES PATENTS the drive shaft.
  • the invention relates to a hammer drill having a tool spindle for receiving the stem of a drilling tool and arranged to be rotatably driven by a drive shaft arranged parallel to the axis of the spindle.
  • the provided hammer drill has a striking mechanism including a striker member which projects into the tool spindle and is arranged to be cyclically withdrawn against a spring and then released for a striking movement by a ballistic can carried on the drive shaft for rotation thereby.
  • the hammer drill hereinafter described may function solely as a drill with no hammer action by means ofa cam disengagement as will hereinafter be explained in greater detail.
  • the striker member of the providedhammer drill can be hollow, with both an anvil spring and a spring stop bolt projecting into the hollow member.
  • the spring is supported at its front end either on an inner shoulder provided in the striker member or on an outer shoulder of the spring stop bolt, according to the position of the striker member utilizing such construction.
  • the striker member spring is trapped or held by the bolt shortly before the impact of the striker member on the tool stem, so that the striker member performs a small movement before it strikes the tool.
  • a hammer drill having a hollow spindle for receiving a drilling tool.
  • a drive shaft is arranged to rotate the spindle and extends parrallel thereto.
  • a striker member is receivable in a rear portion of the spindle, and a ballistic cam on the drive shaft is arranged to be rotated thereby to cause the striker member to be cyclically withdrawn against a spring and released to effect a striking action against the hollow spindle.
  • the striker member is adapted to advance beyond the normal striking position on removal of the tool from a workpiece and thereby prevent rotation of the ballistic cam.
  • the hollow spindle and tool slip forward somewhat, thus permitting the striker member or anvil to proceed forward beyond its normal striking plane and thus prevent the ballistic cam by which it is driven from rotating further on the drive shaft.
  • the striking mechanism is stopped, so that the stresses associated with it and the disturbing effects such as vibration and additional machine noise are prevented.
  • the cam is arranged to be rotatable and axially displaceable on the drive shaft as well as being urged by a spring into coupling engagement with a coupling member torsionally connected with the drive shaft.
  • This coupling member is, however, disengaged as soon as the striker member or anvil extends forward further than normal on removal of the machine from the work, thus immobilizing the ballistic cam which is displaced axially as a consequence by a corresponding amount away from the coupling member on the drive shaft, therefore moving out of rotational engagement with the coupling member.
  • clutch dogs on the coupling member and the cam are provided with correspondingly inclined sides.
  • a check or stop mem ber is provided in the ballistic cam which is arranged to be radially displaceable and is provided with a resiliently supported ball.
  • This stop member is disposed with its inner end in an annular groove in the drive shaft while engaged with a tension element provided on the striking anvil. The tension element cooperates with the ballistic cam while the striker member is in the outermost advanced position engaging the ball of the check member.
  • the striker member or anvil is also preferably positively located in its outermosr advance position.
  • a groove is provided around the anvil into which is received a retaining ring, for example, an O- ring provided on the tool spindle, when the anvil is at its outermost advance position.
  • switch member provided in the machine casing which can be rotatably adjusted from outside, and which allows the ballistic cam to come out of engagement with the coupling member by axial displacement, thereby stopping the striking mechanism.
  • FIGS. 1, 2 and 3 are fragmentary elevational views, partly in section, which schematically show part of the mechanism of the hammer drill in different working and adjusting phases;
  • FIG. 4 is a fragmentary sectional side view partly in elevation of a hammer drill made pursuant to this invention DESCRIPTION OF THE INVENTION
  • the hammer drilling machine shown in FIG. 4 has a housing 1 comprising several portions of which the rearmost portion, which is not illustrated, accommodates an electric motor.
  • the armature spindle 2 of the motor is journalled in a middle housing portion 1' by means of a roller bearing 3.
  • the forwardly projecting end of the spindle 2 carries or is formed as a pinion 4 in engagement with a pinion 6 mounted on a drive shaft 5.
  • the drive shaft transfers the rotating drive of the spindle 2 by means of a pair of meshing gear wheels 7 to a tool holder shaft 8 rotatablyjournalled in the front portion of the housing 1 by roller bearings 9, 10.
  • the axes of the tool holder shaft 8, the drive shaft and the armature spindle 2 are parallel.
  • a drilling tool 11 with a stem 11' is received in a bore 8' opening from the forward end of the tool holder shaft 8, the stem 11 having a multi-sided cross-section corresponding to that of the bore 8'.
  • a striker member or anvil 12 has a stem 12' projecting into the bore of the tool holder shaft 8 from the -rear.
  • the anvil 12 is provided with a channel 13 extending around it, into which a reslient retainer ring 14,
  • a conventional O-ring engaging on a rear surface of the tool holder shaft 8, engages when the anvil is in its outermost advanced position. In this way, the anvil 12 is restrained-against movement from its outermost advance position.
  • An anvil spring 15 and a spring stop bolt 16 project fro the rear into the interior of the anvil 12.
  • the spring 15 is supported at its rear end on a spring plate 15 in the middle housing portion 1' and the stop bolt 16 is attached at its rear end to this housing portion 1' by means of a transversely extending pin 17.
  • the forward end 16 of the spring stop bolt is outwardly flared like a trumpet and forms an outer shoulder serving as an abutment for the spring, as shown in FIG. 4.
  • the spring 15 is supported equally well on an inner shoulder 12 provided in the anvil.
  • a tension element 12" is provided on the anvil 12 for cooperation with a ballistic cam 18 mounted for rotation and axial displacement on the drive shaft 5.
  • the cam 18 can be engaged in a manner enabling transmission of strong torsional forces with inclined sides l9'of a clutch or coupling member 19, which is securely mounted on the drive shaft 5 for rotation therewith.
  • a spring 20 functions to urge the ballistic cam 18 into this coupling engagement with the coupling member 19.
  • FIG. 1 shows the normal position of the striking mechanism.
  • the stem 11' of the tool 11 extends so far into the tool spindle 8 that the anvil 12 comes to rest with the tension element 12" on the sliding surface 18" of the cam 18.
  • the coupling member 19 causes the ballistic cam 18 to rotate with it. Since the ballistic or sliding angle a between the sliding surface 18" and the plane extending through the tension element 12" is smaller than the angle B of the sides of the clutch dogs 18, the force P between the cam 18 and the tension element 12 is greater than the forece Q between the dogs 18' and the clutch element 19. Consequently, the ballistic cam 18 cannot rise up the inclined sides 19' of the coupling member 19 but remains securely coupled thereto.
  • the anvil 12 moves forward beyond its normal range of impacting movement to a position in which it is firmly held by engagement of the O-ring 14 in the channel 13. Since in this position the previously-mentioned sliding angle a is greater than the angle B, the force Q is greater than the force P.
  • the ballistic cam 18 is consequently displaced axially from the clutch member 19 and is so uncoupled from it. The cam 18 thus reaches an idling position illustrated in FIG. 3.
  • the cam 18 is retained in this position by a stop member 21 which is received in the cam for displacement radially of it.
  • the stop member 21 is provided at its outer end with a ball 22 urged outwardly by a spring 21.
  • the tension element 12" of the anvil l2 presses against this ball 22 in the outermost advance position of the-anvil.
  • the stop member 20 is thereby pressed inward so as to enter an annular groove 5 in the drive shaft 5, the cam 18 being then axially displaced by a corresponding amount so that sufficient idling clearance 23 remains between the dogs 18' and the coupling member 19.
  • the anvil 12 is pushed back from its most advanced position by the drilling tool 11, so that the stop member 21 is freed from engagement by the tension element 12 of the anvil 12.
  • the ballistic cam 18 is thus displaced in the direction towads the coupling member 19 by the spring 20, so that the'clutch dogs 18 jump back into the corresponding coupling recesses on the coupling member.
  • the working position illustrated in FIG. 1 has then been reporducedv
  • the mode of operation of the machine can be changed from hammer drilling to simple drilling.
  • a control rod 26 journalled in the front part of the housing 1, for rotation between various angular positions, is provided at its inner end with an inclined end surface 26.
  • the cam 18 can be released from its coupling with the coupling member 19 by axial displacement of the cam due to appropriate rotation of the control rod 26, whereby rotation of the cam 18 and thus the whole striking mechanism will remain switched off even when the machine is pressed against the workpiece, and the machine operates simply as a drill.
  • a hammer drill having a hollow spindle for receiving a drilling tool, a drive shaft arranged to rotate the spindle and extending parrallel thereto, a striker member receivable in the spindle, and a ballistic cam on the drive shaft arranged to be rotated thereby to cause the striker member to be cyclically withdrawn against a spring and released to effect a striking action; the striker member being arranged to advance beyond the normal striking position on removal of the tool from a workpiece and thereby prevent rotation of the ballistic cam; said ballistic cam being rotatable and axially displaceable on the drive shaft and urged by a second spring towards coupling engagement with a coupling member having clutch dogs and said ballistic cam having sides inclined at an angle to a plane transverse to the drive shaft greater than the angle between the plane and surfaces of the ballistic cam and of the striker member which slidably engage during the withdrawal of the striker member.
  • a hammer drill having a hollow spindle for receiving a drilling tool, a drive shaft arranged to rotate the spindle and extending parallel thereto, a striker member receivable in the spindle, and a ballistic cam on the drive shaft arranged to be rotated thereby to cause the striker member to be cyclically withdrawn against a spring and released to effect a striking action, the striker member being arranged to advance beyond the normal striking position on removal of the tool from a workpiece and thereby prevent rotation of the ballistic cam; said ballistic cam being rotatable and axially displaceable on the drive shaft and urged by a second 5 'rin towards cou lin en a ement with a cou lin P g P g g g P 8 member mounted to rotate with the drive shaft; said coupling member having clutch dogs and said ballistic cam having sides inclined at an angle to a plane transverse to the drive shaft greater than the angle between the plane and surfaces of the ballistic cam and of the striker member which
  • a hammer drill having a hollow spindle for receiving a drilling tool, a drive shaft arranged to rotate the spindle and extending parrallel thereto, a striker member receivable in the spindle, and a ballistic cam on the drive shaft arranged to be rotated thereby to cause the striker member to be cyclically withdrawn against a spring and released to effect a striking action, the striker member being arranged to advance beyond the normal striking position on removal of the tool from a workpiece and thereby prevent rotation of the ballistic cam; said ballistic cam being rotatable and axially displaceable on the drive shaft and urged by a second spring towards coupling engagement with a coupling member mounted to rotate with the drive shaft; said coupling member having clutch dogs and said ballistic cam having sides inclined at an angle to a plane transverse to the drive shaft greater than the angle between the plane and surfaces of the ballistic cam and of the striker member which slidably engage during the withdrawal of the striker member; said ballistic cam also having a radi

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Percussive Tools And Related Accessories (AREA)
  • Drilling And Boring (AREA)
US00315425A 1971-12-28 1972-12-15 Hammer drills Expired - Lifetime US3841418A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19712165066 DE2165066B2 (de) 1971-12-28 1971-12-28 Drehschlagbohrmaschine

Publications (1)

Publication Number Publication Date
US3841418A true US3841418A (en) 1974-10-15

Family

ID=5829484

Family Applications (1)

Application Number Title Priority Date Filing Date
US00315425A Expired - Lifetime US3841418A (en) 1971-12-28 1972-12-15 Hammer drills

Country Status (9)

Country Link
US (1) US3841418A (sv)
AT (1) AT327076B (sv)
CH (1) CH551561A (sv)
DE (1) DE2165066B2 (sv)
FR (1) FR2166946A5 (sv)
GB (1) GB1407285A (sv)
IT (1) IT972128B (sv)
NL (1) NL7214600A (sv)
SE (1) SE397991B (sv)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4064949A (en) * 1975-09-12 1977-12-27 Hilti Aktiengesellschaft Electropneumatic hammer
US4135585A (en) * 1977-09-09 1979-01-23 Wagner Gary L Drill rig-casing driver assembly
US4325436A (en) * 1980-05-21 1982-04-20 Hilti Aktiengesellschaft Hammer drill or chipping hammer device
US4641714A (en) * 1983-11-18 1987-02-10 Filippo Ferioli Multiuse portable equipment for driving rotating tools, rotating percussion tools and percussion tools
US4798249A (en) * 1986-10-03 1989-01-17 Hilti Aktiengesellschaft Lockable striking mechanism for hammer drill
US6213222B1 (en) 2000-01-06 2001-04-10 Milwaukee Electric Tool Corporation Cam drive mechanism
US20040026097A1 (en) * 2001-10-05 2004-02-12 Joachim Hecht Manual machine tool
US20040159452A1 (en) * 2002-12-10 2004-08-19 Garvey Seamus D. Apparatus for producing self-exciting hammer action, and rotary power tool incorporating such apparatus
US6814153B2 (en) * 2000-11-30 2004-11-09 Robert Bosch Gmbh Hand power tool
US20070007024A1 (en) * 2005-07-08 2007-01-11 Junichi Tokairin Vibration drill unit
US7350592B2 (en) 2005-02-10 2008-04-01 Black & Decker Inc. Hammer drill with camming hammer drive mechanism
US20090242222A1 (en) * 2008-03-25 2009-10-01 Makita Corporation Impact tool
US9206577B2 (en) 2011-05-11 2015-12-08 Dynamatic Solutions, Llc Impact tool assembly and method of assembling same
US10414035B2 (en) * 2014-12-03 2019-09-17 Hilti Aktiengesellschaft Handheld power tool

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2438490C2 (de) * 1974-08-10 1985-09-26 C. & E. Fein Gmbh & Co, 7000 Stuttgart Getriebe für einen elektromotorisch angetriebenen tragbaren Bohrhammer
DE2655899A1 (de) * 1976-12-09 1978-06-22 Bosch Gmbh Robert Handwerkzeugmaschine
DE2839906A1 (de) * 1978-09-14 1980-03-27 Fein C & E Schlagmechanismus fuer einen bohrhammer
DE2916499A1 (de) * 1979-04-24 1980-11-06 Duss Maschf Elektro-handbohrmaschine mit vorrichtung zur wahlweisen umstellung fuer drehendes oder schlagendes bohren
GB2121716B (en) * 1982-06-11 1985-07-31 Coal Ind Hydraulic reciprocating tools
SU1209840A1 (ru) * 1983-09-02 1986-02-07 Всесоюзный Научно-Исследовательский И Проектно-Конструкторский Институт Механизированного И Ручного Строительно-Монтажного Инструмента,Вибраторов И Строительно-Отделочных Машин Перфоратор
DE3884522D1 (de) * 1987-03-05 1993-11-04 Bosch Gmbh Robert Verfahren zum unterbrechen der antriebstaetigkeit, insbesondere der schlag- und/oder drehantriebstaetigkeit, einer handwerkzeugmaschine.
DE4102692C2 (de) * 1990-03-01 1994-06-23 Masch Service Gmbh Rotor für Prall- oder Hammermühlen
DE4030027A1 (de) * 1990-09-22 1992-03-26 Bosch Gmbh Robert Schlagbohrmaschine
DE19728727C1 (de) * 1997-07-04 1999-02-18 Wacker Werke Kg Schlag- und/oder Bohrhammer mit Leerlaufkupplung

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US952255A (en) * 1904-05-31 1910-03-15 Northern Electrical Mfg Company Power-hammer.
US2016829A (en) * 1934-11-06 1935-10-08 Firm Kapital & Industriewerte Modification of the electrically driven percussion drill
US2260070A (en) * 1941-01-09 1941-10-21 Black & Decker Mfg Co Portable hammer
US2877820A (en) * 1956-12-17 1959-03-17 Milwaukee Electric Tool Corp Power hammer
US3334694A (en) * 1965-01-12 1967-08-08 Milwaukee Electric Tool Corp Rotary hammer
US3685594A (en) * 1970-08-03 1972-08-22 Rockwell Mfg Co Rotary hammer or the like
US3695365A (en) * 1969-11-14 1972-10-03 Bosch Gmbh Robert Torque and impulse transmitting machine

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US952255A (en) * 1904-05-31 1910-03-15 Northern Electrical Mfg Company Power-hammer.
US2016829A (en) * 1934-11-06 1935-10-08 Firm Kapital & Industriewerte Modification of the electrically driven percussion drill
US2260070A (en) * 1941-01-09 1941-10-21 Black & Decker Mfg Co Portable hammer
US2877820A (en) * 1956-12-17 1959-03-17 Milwaukee Electric Tool Corp Power hammer
US3334694A (en) * 1965-01-12 1967-08-08 Milwaukee Electric Tool Corp Rotary hammer
US3695365A (en) * 1969-11-14 1972-10-03 Bosch Gmbh Robert Torque and impulse transmitting machine
US3685594A (en) * 1970-08-03 1972-08-22 Rockwell Mfg Co Rotary hammer or the like

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4064949A (en) * 1975-09-12 1977-12-27 Hilti Aktiengesellschaft Electropneumatic hammer
US4135585A (en) * 1977-09-09 1979-01-23 Wagner Gary L Drill rig-casing driver assembly
US4325436A (en) * 1980-05-21 1982-04-20 Hilti Aktiengesellschaft Hammer drill or chipping hammer device
US4641714A (en) * 1983-11-18 1987-02-10 Filippo Ferioli Multiuse portable equipment for driving rotating tools, rotating percussion tools and percussion tools
US4798249A (en) * 1986-10-03 1989-01-17 Hilti Aktiengesellschaft Lockable striking mechanism for hammer drill
US6213222B1 (en) 2000-01-06 2001-04-10 Milwaukee Electric Tool Corporation Cam drive mechanism
EP1114700A2 (en) * 2000-01-06 2001-07-11 Milwaukee Electric Tool Corporation Cam drive mechanism
EP1114700A3 (en) * 2000-01-06 2003-09-10 Milwaukee Electric Tool Corporation Cam drive mechanism
US6814153B2 (en) * 2000-11-30 2004-11-09 Robert Bosch Gmbh Hand power tool
US20040026097A1 (en) * 2001-10-05 2004-02-12 Joachim Hecht Manual machine tool
US6988562B2 (en) * 2001-10-05 2006-01-24 Robert Bosch Gmbh Manual machine tool
US20040159452A1 (en) * 2002-12-10 2004-08-19 Garvey Seamus D. Apparatus for producing self-exciting hammer action, and rotary power tool incorporating such apparatus
US7036608B2 (en) * 2002-12-10 2006-05-02 Black & Decker Inc. Apparatus for producing self-exciting hammer action, and rotary power tool incorporating such apparatus
US7350592B2 (en) 2005-02-10 2008-04-01 Black & Decker Inc. Hammer drill with camming hammer drive mechanism
US20070007024A1 (en) * 2005-07-08 2007-01-11 Junichi Tokairin Vibration drill unit
US8672049B2 (en) * 2005-07-08 2014-03-18 Hitachi Koki Co., Ltd. Vibration drill unit
US20090242222A1 (en) * 2008-03-25 2009-10-01 Makita Corporation Impact tool
US7918286B2 (en) * 2008-03-25 2011-04-05 Makita Corporation Impact tool
US9206577B2 (en) 2011-05-11 2015-12-08 Dynamatic Solutions, Llc Impact tool assembly and method of assembling same
US10414035B2 (en) * 2014-12-03 2019-09-17 Hilti Aktiengesellschaft Handheld power tool

Also Published As

Publication number Publication date
ATA863972A (de) 1975-03-15
DE2165066B2 (de) 1976-12-02
AT327076B (de) 1976-01-12
CH551561A (de) 1974-07-15
SE397991B (sv) 1977-11-28
NL7214600A (sv) 1973-07-02
GB1407285A (en) 1975-09-24
FR2166946A5 (sv) 1973-08-17
IT972128B (it) 1974-05-20
DE2165066A1 (de) 1973-07-05

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