EP0077182A2 - Druckluftgetriebenes Gerät - Google Patents

Druckluftgetriebenes Gerät Download PDF

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Publication number
EP0077182A2
EP0077182A2 EP82305341A EP82305341A EP0077182A2 EP 0077182 A2 EP0077182 A2 EP 0077182A2 EP 82305341 A EP82305341 A EP 82305341A EP 82305341 A EP82305341 A EP 82305341A EP 0077182 A2 EP0077182 A2 EP 0077182A2
Authority
EP
European Patent Office
Prior art keywords
valve
motor
latch member
operating member
drive shaft
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.)
Withdrawn
Application number
EP82305341A
Other languages
English (en)
French (fr)
Other versions
EP0077182A3 (de
Inventor
Richard Ernest Eckman
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.)
Dresser Industries Inc
Original Assignee
Dresser Industries Inc
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 Dresser Industries Inc filed Critical Dresser Industries Inc
Publication of EP0077182A2 publication Critical patent/EP0077182A2/de
Publication of EP0077182A3 publication Critical patent/EP0077182A3/de
Withdrawn legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
    • B25B23/00—Details of, or accessories for, spanners, wrenches, screwdrivers
    • B25B23/14—Arrangement of torque limiters or torque indicators in wrenches or screwdrivers
    • B25B23/145—Arrangement of torque limiters or torque indicators in wrenches or screwdrivers specially adapted for fluid operated wrenches or screwdrivers

Definitions

  • This invention relates to pneumatically driven apparatus, comprising: a hollow housing; an air motor including a rotatable motor shaft located in the housing, the motor being arranged for connection with a source of pressurized air and the apparatus being arranged to drive a tool such as a screwdriver, socket wrench or the like via a tool drive shaft rotatable in the housing; a torque-sensitive clutch between the tool drive shaft and motor shaft permitting the motor shaft to move relative to the tool drive shaft when a predetermined torque occurs; and a valve in the housing between the motor and the air supply source which, when open, permits air to reach the motor.
  • the valve controls the flow of pressurized air from the source to the pneumatic motor contained within the tool.
  • Apparatus for controlling the opening and closing of such valves has been the subject of much work and several patents for many years.
  • U.S. patent 2,964,151 illustrates apparatus for controlling the valve. While that apparatus operates satisfactorily, it does have certain drawbacks, such as the imbalance caused by the valve control mechanism. Such imbalance is magnified as a vibration problem unless carefully counterbalanced when used in the high rotational speed tools of present pneumatic apparatus.
  • control apparatus is illustrated in U.S. patent 4,154,308.
  • the control apparatus illustrated therein utilizes a sliding latch member that engages the valve control rod to control the open and closed positions of the valve.
  • the sliding latch member utilizes some of the imbalance by a particular arrangement of a centroid or center of mass of the sliding member to maintain it in the desired position during the rotation of the tool.
  • a valve controller for holding the valve open and for releasing the valve to permit closing said valve controller including: an elongate valve operating member in the housing having a first end engaging said valve and having a second end; a latch member in the housing pivotal on the tool drive shaft, said latch member having a surface thereon facing said valve for engaging the second end of said valve operating member, said surface having a hole therein sized to receive the second end of said elongated valve operating member; a portion on said latch member engageable with the motor shaft upon relative movement between the shafts to pivot said latch member from a first position in which said hole is out of alignment with said operating member into a second position in which said hole is in alignment with said valve operating member permitting said valve operating member to move thereby closing said valve; and, resilient means biasing said latch member toward said first position.
  • the present invention provides a valve control apparatus for pneumatically driven tools that reduces vibration problems imposed by such apparatus and that will function effectively while requiring a small amount of radial movement of the valve control apparatus.
  • the screwdriver 10 includes a fitting 12 for connection to a supply of air under pressure (not shown).
  • the screwdriver 10 will, of course, be provided with the necessary flow passageways, ports, etc. to cause the motor 16 to operate when desired, and to rotate in the direction desired.
  • valve 14 and air motor 16 as well as other components of the screwdriver 10 are housed in a hollow case or housing 18.
  • the air motor 16 includes a hollow motor output shaft 20 that is operatively connected to a tool drive shaft 22 by means of a clutch assembly 24.
  • the speed of the shaft 22 is in proportion to the speed of the shaft 20 due to a gear reduction train 26 that is operatively disposed therebetween.
  • the gear reduction train 26 includes a sliding connection (not shown) to permit the train to partially collapse or telescope during operation of the tool 10.
  • the tool drive shaft 22 drives a screwdriver bit 28 through mating hexagonal surfaces 30 that are on the exterior of screwdriver 28 and in a bore 32 of the shaft 22.
  • a ball detent 34 retains the screwdriver against longitudinal movement in the shaft 22.
  • the blade of the screwdriver 28 extends close to the end of the nose 36 of the tool body 18.
  • the nose 36 is slideable within the housing 18 and is retained in the position illustrated by a coil spring 38.
  • the nose 36 can move upwardly into the housing 18 to expose the end or blade of the screwdriver 28.
  • the clutch assembly 24 is shown in more detail.
  • the motor output shaft 20 is rotatable in and relative to the tool drive shaft 22 through a plurality of ball bearings 40 that are disposed therebetween.
  • the tool drive shaft 22 is provided with a plurality of recesses forming ramps 42 in which a plurality of clutch balls 44 are located.
  • the balls 44 are disposed within openings 46 that are located in a flange 48 mounted on the end of the output shaft 20 and are, thus, rotatable with the motor output shaft 20.
  • a ball housing 50 encompasses the balls 44 and prevents the balls from becoming dislodged from the openings 46.
  • An output shaft 20 carries a spring biasing the balls 44 into the recesses adjacent to the ramps 42 formed in the tool drive shaft 22. Thus, so long as the balls 44 do not run up and over the ramps 42, the tool drive shaft 22 is operatively connected to the motor output shaft 20.
  • the ramps 42, balls 44, flange 48 and related parts constitute the clutch assembly 24.
  • the tool drive shaft 22 is driven by the motor output shaft 20 through the clutch assembly 24.
  • the balls 44 ride up the ramps 42 and over into the next ramp 42 thus permitting rotation of the motor output shaft 20 relative to the tool drive shaft 22.
  • the air supply to the motor 16 is shut off by closing the valve 14 as will be described.
  • valve 14 is in the open position and air can flow thereby to the air motor 16.
  • the valve 14 is retained in the open position by a valve control rod 54, which has one end 56 in engagement with the valve 14, and the other end 58 in engagement with a surface 60 on a pivotal latch member 62. It should be realized that in order to hold the valve 14 open, it is necessary to retain the tool drive shaft 22 displaced to the right as seen in Figs. 4A and B by engagement of the screwdriver bit 28 with the threaded fastener.
  • the latch member 62 is pivotally mounted on the right end (as seen in Fig. 4B) of the tool drive shaft 22 by pivot pin 64. As shown in Fig. 5, the end 66 of the motor output shaft 20, is triangular in configuration and is disposed in a recess 68 which forms the surface 60 in the latch member 62. The recess 68 is configured so that the end 66 can rotate therein.
  • the latch member 62 includes a protuberance or cam surface 70 that projects outwardly toward the recess 68 so that it is engageable with the apexes or lobes 72 formed on the triangular end 66 of the motor output shaft 20.
  • a compression spring 74 is located so that one end is in engagement with the tool drive shaft 22 and the opposite end is in engagement with the latch member 62 so that the spring 74 biases the latch member 62 into a position where the cam surface 70 can engage the lobes 72 on the motor output shaft 20 in the event that relative rotation between the motor output shaft 20 and the tool drive shaft 22 occurs.
  • a hole 76 extends through the latch member 62.
  • the hole 76 is sized to receive the end 58 of the valve control rod 54 and, when the hole 76 and the valve control rod 54 are in alignment, the rod 54 can move thereinto.
  • valve control rod 54 retains the valve 14 in the open position since the end 58 of the control rod 54 is in engagement with the surface 60.
  • the flow of fluid past the valve 14 tends to urge the valve 14, which is normally closed, toward the closed position and such hydraulic force is aided by a spring 77 that is disposed between the tool body 18 and the valve 14.
  • the closing of the valve 14 is prevented by the engagement of the end 58 with the surface 60.
  • the motor output shaft 20 is hollow and the control rod 54 extends therethrough.
  • a flange 80 is attached to the valve control rod 54, so that a coil spring 78 encircling the rod 54 acts on the motor output shaft 20 to urge the clutch assembly 24 and tool drive shaft 22 relatively away from the valve 14 so that the control rod 54 is disposed in the interior of the shaft 20.
  • the latch member 62 pivots into the latched position shown in Fig. 5
  • valve 14 is normally closed preventing pressurized fluid from reaching the air motor 16.
  • the screwdriver bit 28 When the screwdriver bit 28 is engaged with the threaded fastener and pressure placed on the tool 10, the bit 28, tool drive shaft 22 and motor output shaft 20 move relatively into the housing 18 telescoping the gear train 26 and by virtue of engagement of the end of the control rod 54 with the latch member 62, by forcing the valve 14 off its seat and permitting fluid flow to the air motor 16.
  • valve 14 remains closed, but the end 58 of the control rod 54 is now again resting on the surface 60 of the latch member 62.Thus, the tool 10 is in position to be reopened when the screwdriver bit 28 is engaged with a threaded fastener and force exerted on the tool 10.
  • the tool 10 incorporates improved apparatus for controlling the position of the valve 14. It should be appreciated by viewing Figs. 5 and 7 that very little movement of the latch member occurs between the latched and unlatched positions of the control rod 54. Accordingly, such apparatus can be manufactured in very small sizes to fit within the small-high speed, pneumatically driven tools currently being manufactured. Also, it will be noticed that the apparatus is constructed so that the latch mechanism will be substantially balanced relative to rotational forces, and will therefore create very little vibration in the tool during high speed operation.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Details Of Spanners, Wrenches, And Screw Drivers And Accessories (AREA)
  • Portable Nailing Machines And Staplers (AREA)
  • Treatment Of Fiber Materials (AREA)
EP82305341A 1981-10-13 1982-10-07 Druckluftgetriebenes Gerät Withdrawn EP0077182A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US31000881A 1981-10-13 1981-10-13
US310008 1981-10-13

Publications (2)

Publication Number Publication Date
EP0077182A2 true EP0077182A2 (de) 1983-04-20
EP0077182A3 EP0077182A3 (de) 1984-07-11

Family

ID=23200601

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82305341A Withdrawn EP0077182A3 (de) 1981-10-13 1982-10-07 Druckluftgetriebenes Gerät

Country Status (3)

Country Link
EP (1) EP0077182A3 (de)
JP (1) JPS5877459A (de)
AR (1) AR228918A1 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101269484B (zh) * 2008-04-24 2010-06-09 吴逸民 动力定扭扳手

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3477521A (en) * 1967-10-05 1969-11-11 Aro Corp Automatic power tool
DE2409815A1 (de) * 1974-03-01 1975-09-11 Bosch Gmbh Robert Kraftschrauber mit abschalteinrichtung
US4154308A (en) * 1977-10-25 1979-05-15 Dresser Industries, Inc. Low torque automatic screwdriver
GB2040768A (en) * 1979-01-17 1980-09-03 Dresser Ind Torque responsive shut-off apparatus for pneumatic driven tools

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3477521A (en) * 1967-10-05 1969-11-11 Aro Corp Automatic power tool
DE2409815A1 (de) * 1974-03-01 1975-09-11 Bosch Gmbh Robert Kraftschrauber mit abschalteinrichtung
US4154308A (en) * 1977-10-25 1979-05-15 Dresser Industries, Inc. Low torque automatic screwdriver
GB2040768A (en) * 1979-01-17 1980-09-03 Dresser Ind Torque responsive shut-off apparatus for pneumatic driven tools

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101269484B (zh) * 2008-04-24 2010-06-09 吴逸民 动力定扭扳手

Also Published As

Publication number Publication date
AR228918A1 (es) 1983-04-29
JPS5877459A (ja) 1983-05-10
EP0077182A3 (de) 1984-07-11

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Legal Events

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PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

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AK Designated contracting states

Designated state(s): BE DE FR GB IT LU NL SE

PUAL Search report despatched

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STAA Information on the status of an ep patent application or granted ep patent

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18D Application deemed to be withdrawn

Effective date: 19850617

RIN1 Information on inventor provided before grant (corrected)

Inventor name: ECKMAN, RICHARD ERNEST