US3570608A - Hammer mechanism for percussion tools - Google Patents

Hammer mechanism for percussion tools Download PDF

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Publication number
US3570608A
US3570608A US821554A US3570608DA US3570608A US 3570608 A US3570608 A US 3570608A US 821554 A US821554 A US 821554A US 3570608D A US3570608D A US 3570608DA US 3570608 A US3570608 A US 3570608A
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US
United States
Prior art keywords
hammer
piston
abutment
ring
hammer piston
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
US821554A
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English (en)
Inventor
Eero Antero Erma
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.)
Atlas Copco AB
Original Assignee
Atlas Copco AB
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 Atlas Copco AB filed Critical Atlas Copco AB
Application granted granted Critical
Publication of US3570608A publication Critical patent/US3570608A/en
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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
    • B25D9/00—Portable percussive tools with fluid-pressure drive, i.e. driven directly by fluids, e.g. having several percussive tool bits operated simultaneously
    • B25D9/06—Means for driving the impulse member
    • B25D9/10—Means for driving the impulse member comprising a built-in internal-combustion engine
    • 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
    • B25D11/06—Means for driving the impulse member
    • B25D11/12—Means for driving the impulse member comprising a crank mechanism
    • B25D11/125—Means for driving the impulse member comprising a crank mechanism with a fluid cushion between the crank drive and the striking body
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25D—PERCUSSIVE TOOLS
    • B25D9/00—Portable percussive tools with fluid-pressure drive, i.e. driven directly by fluids, e.g. having several percussive tool bits operated simultaneously
    • B25D9/06—Means for driving the impulse member
    • B25D9/08—Means for driving the impulse member comprising a built-in air compressor, i.e. the tool being driven by air pressure
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B1/00—Percussion drilling
    • E21B1/12—Percussion drilling with a reciprocating impulse member
    • E21B1/24—Percussion drilling with a reciprocating impulse member the impulse member being a piston driven directly by fluid pressure
    • E21B1/30—Percussion drilling with a reciprocating impulse member the impulse member being a piston driven directly by fluid pressure by air, steam or gas pressure
    • E21B1/32—Percussion drilling with a reciprocating impulse member the impulse member being a piston driven directly by fluid pressure by air, steam or gas pressure working with pulses
    • E21B1/34—Percussion drilling with a reciprocating impulse member the impulse member being a piston driven directly by fluid pressure by air, steam or gas pressure working with pulses the impulse member being a piston of an internal-combustion engine

Definitions

  • This invention relates to a hammer mechanism for percussion tools of the type having a working piston which by means of a pressure medium in a working chamber for said piston drives a hammer piston which transmits its kinetic energy to a percussion implement.
  • the invention is particularly applicable to portable rock drills driven by internal combustion engines, but may also be utilized in conjunction with other types of hammer mechanisms irrespectively of the nature of the power source.
  • the combustion gases drive the rock drill hammer piston directly, the hammer piston and a captive engine piston being arranged in one cylinder, in which the hammer piston absorbs as kinetic energy the energy liberated by the combustion process.
  • the hammer piston After having delivered a blow to a percussion implement the hammer piston returns towards the internal combustion engine piston by action of a superatmospheric pressure in a chamber positioned below the hammer piston.
  • the return velocity and the length of the return stroke of the hammer piston is also at least partially dependent upon the hardness of the material to be treated by the percussion implement and the recoil from the percussion implement and the material to be treated. This implies that the hammer piston is not always in proper position relatively to the engine piston when combustion starts, and this happens especially when the material to be treated has varying hardness. The result is uneven running of the engine.
  • the position of the spark plug in said known rock drill is an additional drawback, since said spark plug has to be positioned in the sidewall of the combustion chamber, resulting in an unsymmetrical combustion chamber and a disadvantageous combustion process causing incomplete combustion.
  • the engine speed has to be limited to a low value, which is disadvantageous with regard to the output.
  • One object of the invention is to provide a hammer mechanism for percussion tools which eliminates said recoil drawbacks and which may be operated at a considerably higher number of revolutions than has been possible in conventional portable rock drills, particularly in those driven by internal combustions engines.
  • the hammer mechanism according to the invention is characterized by a hammer member arranged to be movable relatively to said hammer piston in the direction of motion thereof, a first abutment in the hammer mechanism which limits the movement of the hammer member in a first direction, a return motion chamber for the hammer piston in which a pressure medium acts on the hammer piston in a second opposite direction, means for biasing said hammer member towards a resting position on said first abutment when the hammer piston delivers a blow to said percussion implement, a second abutment on the hammer member, and a third abutment on the hammer piston arranged to cooperate with said second abutment so that when the hammer piston has delivered a blow the hammer piston is moved in said second direction by the pressure medium in said return chamber until said third abutment engages the second abutment, the mass of the hammer member being so dimensioned relatively to the mass of the hammer piston as to cause the ham
  • the hammer is a hammer ring which concentrically encloses and slidably cooperates with the hammer piston and together with the hammer piston defines the return chamber, the pressure medium in said return chamber forming the means for biasing the hammer member.
  • a great advantage of the hammer mechanism according to the present invention lies above all in the fact that the number of revolutions of the hammer mechanism or the number of blows of the hammer piston may be optimized so that the greatest possible amount of working energy may be delivered per time unit by the hammer mechanism which has not been possible when using previously known machines because of the low maximum number of blows thereof.
  • FIG. 1 is a side view partially in section of a rock drill provided with a hammer mechanism according to the invention.
  • FIG. 2A and 2B are diagrams illustrating the hammer piston and the hammer ring movement, respectively, as a function of time between uppermost and lowermost piston and ring positions.
  • FIG. 3 is a diagram illustrating the total impact energy per minute as well as the impact energy per blow as a function of the number of blows of the hammer piston or the number of revolutions of the engine.
  • the rock drill illustrated in FIG. 1- cornprises a conventional internal combustion engine provided with a cooling fins l, a cylinder 2, a piston 3, a spark plug 4, a connecting rod 5, a flywheel 27, and a crank shaft 6.
  • a connecting rod 7 for a compressor or working position 8 reciprocable in a compressor cylinder 9 is journaled on the crank shaft the direction of the connecting rod 7 being opposite that of the connecting rod 5.
  • An inlet opening 10 for air to a compression chamber 11 is provided in the wall of the cylinder 9. The pressure in said chamber ranges between 0 and l5 atmospheres gauge, for instance.
  • the compression chamber ll is limited downwards by a hammer piston 32, a hammer ring 13 being arranged concentrically around the hammer piston and serving as an auxiliary piston for the hammer piston.
  • a return chamber 14 is disposed concentrically between the hammer piston i2 and the hammer ring 13, said return chamber having permanently a superatmospheric pressure ranging between about I and L5 atmospheres gauge, for instance.
  • Compressed air is supplied to the return chamber for the chamber ll, for instance through the clearance around the hammer piston 12.
  • the hammer ring 13 is fitted in the casing 21 of the hammer mechanism which provides a seat 18 forming a first abutment for the hammer ring 13.
  • the hammer ring l3 has an internal annular flange 16 which forms a second abutment cooperating with a third abutment formed by an external annular flange 15 on the hammer piston 12.
  • the hammer ring 13 forms a seal with the hammer piston at 19.
  • the hammer ring flange l6 during the upward movement of the hammer piston is engaged by the third abutment formed on the hammer piston flange 15.
  • the hammer piston is guided in the casing 21 at 17.
  • the first abutment 18 limits the downward motion of the hammer ring T3.
  • the hammer ring 13 has a cylindrical guiding and sealing surface 20 which cooperates with a bore in the casing 2! of the hammer mechanism.
  • Flushing air is supplied to a flushing duct 25 in a drilling implement 22 through passages 23 and 24 as indicated by arrows or through a passage. in the hammer piston.
  • a drill sleeve and a rotary driver 26 are arranged for the drill steel rotation.
  • the engine piston and compressor or working piston are shown in their uppermost positions in the cylinders, i.e. in the positions near the crankshaft.
  • the engine piston 3 by means of the kinetic energy stored in the flywheel 27, compresses the fuelair mixture in the cylinder 2 for the succeeding combustion.
  • the compressor piston 8 compresses the air in the compression chamber ill from atmospheric pressure to about 15 atmospheres gauge.
  • the hammer piston 12 begins its downward movement in the cylinder 9 when the pressure in the compression chamber exceeds 1 atmosphere guage, due to the superatmospheric pressure of about 1 atmosphere gauge which exists in the return chamber M and which opposes said downward motion.
  • the compressor piston 8 is thereby forced upwards.
  • the hammer piston begins its upward movement when the pressure in the compression chamber 11 has dropped below 1.5-atmospheres gauge.
  • the third abutment on the flange engages the second abutment on the flange R6 of the hammer ring 13 which was at rest on the first abutment 118.
  • the masses of the hammer piston and the hammer ring are so mutually dimensioned as to ensure that the hammer piston always stops when striking the hammer ring irrespectively of the magnitude of the recoil from the drill steel and the material to be treated by the drill steel, whereas the hammer ring continues upwards thereby compressing air in a chamber 28 formed between the flange l6 and the cylinder.
  • the ring 13 travels upwards a distance which is partially dependent on the magnitude or the recoil.
  • the hammer ring then returns into engagement with the abutment 18 when the hammer piston has again started its downward movement during the succeeding working stroke.
  • the initial position of the hammer piston is always the same at the beginning of each stroke.
  • the hammer piston stops against the hammer ring and the hammer piston remains in this uppermost position during a time interval which is somewhat shorter than the time required for the up-down movement of the hammer ring.
  • the hammer piston has its normal or rest position at the uppermost point of its motion whereas the hammer ring has its normal or rest position at its lowermost point.
  • FIG. 3 is a diagram illustrating how the total impact energy E per time unit and the impact energy e per stroke varies as a function of the number of blows of the hammer piston.
  • the total impact energy E may be optimized by proper choice of the distance a. The optimum is not reached when the impact energy e per stroke has its maximum but at a somewhat greater number of blows, as is obvious from FIG. 3. This high number of blows has not been possible to reach in prior forms of hammer mechanisms of this type having the hammer piston driven directly by means of the combustion gases in the cylinder of an internal combustion engine.
  • the optimizing of the impact energy per minute is of great advantage and is made possible by the hammer ring which serves as an auxiliary hammer piston.
  • a hammer mechanism for a percussion tool particularly for a portable rock drill of the type having a working piston which by means of a pressure medium in a working chamber for said piston drives a hammer piston which transmits its kinetic energy to a percussion implement, said hammer mechanism having a hammer member arranged movably relatively to said hammer piston in the direction of motion thereof, a first abutment in the hammer mechanism which limits the movement of the hammer member in a first direction, a return motion chamber for the hammer piston in which a pressure medium acts on the hammer piston in a second opposite direction, means for biasing said hammer member towards a resting position on said first abutment when the hammer piston delivers a blow to said percussion implement, a second abutment on the hammer member and a third abutment on the hammer.
  • the mass of the hammer member being so dimensioned relatively to the mass of the hammer piston as to cause the hammer piston motion in the second direction to stop when the third abutment engages the second abutment and the kinetic energy of the hammer piston is delivered to the hammer member, so that the hammer piston always attains well-defined end positions in the hammer mechanism irrespective of the magnitude of the recoil from the percussion implement and the material to be treated.
  • hammer mechanism in which the hammer member is a hammer ring which concentrically encloses and slidably cooperates with the hammer piston and together with the hammer piston defines the return chamber, the pressure medium in said return chamber forming the means for biasing the hammer member.
  • a hammer mechanism for a percussion tool and particularly for a portable rock drill of the type having a working piston which by means of a pressure medium in a working chamber for said piston drives a hammer piston which transmits its kinetic energy to a percussion implement, the hammer piston having a hammer ring arranged concentrically around it and acting as an auxiliary piston for the hammer piston, a casing in which the hammer ring is fitted, said casing having a seat forming a first abutment for the hammer ring, the hammer ring having an annular flange forming a second abutment, said second abutment cooperating with a third abutment formed by an annular flange provided on the hammer piston, the flange on the hammer ring being engaged by the third abutment during the upward movement of the hammer piston and the first abutment limiting the downward movement of the hammer ring.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Combustion & Propulsion (AREA)
  • Chemical & Material Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Earth Drilling (AREA)
  • Percussive Tools And Related Accessories (AREA)
US821554A 1968-05-08 1969-04-30 Hammer mechanism for percussion tools Expired - Lifetime US3570608A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE6221/68A SE319134B (xx) 1968-05-08 1968-05-08

Publications (1)

Publication Number Publication Date
US3570608A true US3570608A (en) 1971-03-16

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ID=20268167

Family Applications (1)

Application Number Title Priority Date Filing Date
US821554A Expired - Lifetime US3570608A (en) 1968-05-08 1969-04-30 Hammer mechanism for percussion tools

Country Status (10)

Country Link
US (1) US3570608A (xx)
AT (1) AT289682B (xx)
BE (1) BE732667A (xx)
CH (1) CH480143A (xx)
DE (1) DE1923512A1 (xx)
ES (1) ES366870A1 (xx)
FR (1) FR2008085A1 (xx)
GB (1) GB1229122A (xx)
NL (1) NL6907052A (xx)
SE (1) SE319134B (xx)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3685593A (en) * 1970-11-03 1972-08-22 Chicago Pneumatic Tool Co Fluid operated rock drill having an independent rotation motor
US3834469A (en) * 1972-11-14 1974-09-10 Wacker Werke Kg Internal combustion operated hammer
USB368081I5 (xx) * 1972-06-30 1975-01-28 Atlas Copco Ab
US3939921A (en) * 1973-12-31 1976-02-24 Atlas Copco Aktiebolag Method and device for damping the movement of a hammer piston
US3973633A (en) * 1972-06-30 1976-08-10 Atlas Copco Aktiebolag Hammer device
US4907567A (en) * 1988-05-12 1990-03-13 Henrich Richard L Adjustable multi function rotary bow stabilizer
US5984027A (en) * 1995-11-13 1999-11-16 Maruzen Kogyo Company Ltd. Engine-driven breaker
US6540034B1 (en) * 2000-04-29 2003-04-01 Westerngeco L.L.C. Portable seismic shothole drilling system
US20030075347A1 (en) * 2000-03-10 2003-04-24 Andreas Hanke Hammer
US20040065455A1 (en) * 2001-03-12 2004-04-08 Rudolf Berger Pneumatic percussive tool with a movement frequency controlled idling position
US20050016744A1 (en) * 2001-11-09 2005-01-27 Shigeru Miyakawa Engine braker
FR2863532A1 (fr) * 2003-12-12 2005-06-17 Sullair Europ Dispositif de commande d'un outil pneumatique au moyen d'une source d'energie independante
US20050274534A1 (en) * 2004-06-11 2005-12-15 Stefan Goetzfried Percussive power tool with flushing head
US10814468B2 (en) 2017-10-20 2020-10-27 Milwaukee Electric Tool Corporation Percussion tool
US10926393B2 (en) 2018-01-26 2021-02-23 Milwaukee Electric Tool Corporation Percussion tool

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB8817907D0 (en) * 1988-07-27 1988-09-01 British Engines Ltd Reciprocating percussive device
WO1991002883A1 (en) * 1989-08-18 1991-03-07 Moskovskoe Nauchno-Proizvodstvennoe Obiedinenie Po Mekhanizirovannomu Stroitelnomu Instrumentu I Otdelochnym Mashinam Perforator

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1060647A (en) * 1911-05-17 1913-05-06 Frederick J Steinbach Concrete-drill.
US2121706A (en) * 1937-07-14 1938-06-21 Daniel W Little Internal combustion engine operated drill
US2239090A (en) * 1940-04-23 1941-04-22 Dewar Mfg Company Inc Portable power hammer

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1060647A (en) * 1911-05-17 1913-05-06 Frederick J Steinbach Concrete-drill.
US2121706A (en) * 1937-07-14 1938-06-21 Daniel W Little Internal combustion engine operated drill
US2239090A (en) * 1940-04-23 1941-04-22 Dewar Mfg Company Inc Portable power hammer

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3685593A (en) * 1970-11-03 1972-08-22 Chicago Pneumatic Tool Co Fluid operated rock drill having an independent rotation motor
USB368081I5 (xx) * 1972-06-30 1975-01-28 Atlas Copco Ab
US3924691A (en) * 1972-06-30 1975-12-09 Atlas Copco Ab Combustion engine driven hammer machines
US3973633A (en) * 1972-06-30 1976-08-10 Atlas Copco Aktiebolag Hammer device
US3834469A (en) * 1972-11-14 1974-09-10 Wacker Werke Kg Internal combustion operated hammer
US3939921A (en) * 1973-12-31 1976-02-24 Atlas Copco Aktiebolag Method and device for damping the movement of a hammer piston
US4907567A (en) * 1988-05-12 1990-03-13 Henrich Richard L Adjustable multi function rotary bow stabilizer
US5984027A (en) * 1995-11-13 1999-11-16 Maruzen Kogyo Company Ltd. Engine-driven breaker
US20030075347A1 (en) * 2000-03-10 2003-04-24 Andreas Hanke Hammer
US6805206B2 (en) * 2000-03-10 2004-10-19 Black & Decker, Inc. Hammer
US6540034B1 (en) * 2000-04-29 2003-04-01 Westerngeco L.L.C. Portable seismic shothole drilling system
US20040065455A1 (en) * 2001-03-12 2004-04-08 Rudolf Berger Pneumatic percussive tool with a movement frequency controlled idling position
US6938704B2 (en) * 2001-03-12 2005-09-06 Wacker Construction Equipment Ag Pneumatic percussive tool with a movement frequency controlled idling position
US20050016744A1 (en) * 2001-11-09 2005-01-27 Shigeru Miyakawa Engine braker
US7124840B2 (en) * 2001-11-09 2006-10-24 Yamada Machinery Industrial Co., Ltd. Engine breaker
FR2863532A1 (fr) * 2003-12-12 2005-06-17 Sullair Europ Dispositif de commande d'un outil pneumatique au moyen d'une source d'energie independante
WO2005058549A1 (fr) * 2003-12-12 2005-06-30 Sullair Europe Dispositif de commande d'un outil pneumatique au moyen d'une source d'energie independante
US20050274534A1 (en) * 2004-06-11 2005-12-15 Stefan Goetzfried Percussive power tool with flushing head
US7252155B2 (en) * 2004-06-11 2007-08-07 Hilti Aktiengesselschaft Percussive power tool with flushing head
US11633843B2 (en) 2017-10-20 2023-04-25 Milwaukee Electric Tool Corporation Percussion tool
US10814468B2 (en) 2017-10-20 2020-10-27 Milwaukee Electric Tool Corporation Percussion tool
US10926393B2 (en) 2018-01-26 2021-02-23 Milwaukee Electric Tool Corporation Percussion tool
US11141850B2 (en) 2018-01-26 2021-10-12 Milwaukee Electric Tool Corporation Percussion tool
US11203105B2 (en) 2018-01-26 2021-12-21 Milwaukee Electric Tool Corporation Percussion tool
US11059155B2 (en) 2018-01-26 2021-07-13 Milwaukee Electric Tool Corporation Percussion tool
US11759935B2 (en) 2018-01-26 2023-09-19 Milwaukee Electric Tool Corporation Percussion tool
US11865687B2 (en) 2018-01-26 2024-01-09 Milwaukee Electric Tool Corporation Percussion tool

Also Published As

Publication number Publication date
CH480143A (de) 1969-10-31
NL6907052A (xx) 1969-11-11
BE732667A (xx) 1969-11-07
SE319134B (xx) 1969-12-22
AT289682B (de) 1971-05-10
ES366870A1 (es) 1971-03-16
FR2008085A1 (xx) 1970-01-16
DE1923512A1 (de) 1971-01-28
GB1229122A (xx) 1971-04-21

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