US3741314A - Pneumatic screwdriver - Google Patents

Pneumatic screwdriver Download PDF

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Publication number
US3741314A
US3741314A US00146030A US3741314DA US3741314A US 3741314 A US3741314 A US 3741314A US 00146030 A US00146030 A US 00146030A US 3741314D A US3741314D A US 3741314DA US 3741314 A US3741314 A US 3741314A
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US
United States
Prior art keywords
weight
rotor
piston
cylinder
drive member
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
US00146030A
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English (en)
Inventor
P Leoni
I Cattini
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NUOVA LAPI
Original Assignee
NUOVA LAPI
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 NUOVA LAPI filed Critical NUOVA LAPI
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Publication of US3741314A publication Critical patent/US3741314A/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
    • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
    • B25B21/00—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose
    • B25B21/02—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose with means for imparting impact to screwdriver blade or nut socket

Definitions

  • the object of the present invention is to provide a screw driving device controlled by a small compressed air motor which does not have the disadvantages which result from the driving impacts of the mobile weight.
  • Another object of the present invention is to provide a screw driving device which has the highest axial moment of inertia which is compatible with the weight and power of the device.
  • Yet another object of the present invention consists in providing means for controlling a compressed air actuated screwdriver in a simple way which increases both the strength, and durability of the device, and renders it economical to construct.
  • the objects of the invention are attained by the translational movement along the axis of the movable weight in dependence upon automatic pneumatic control means and by also providing a motor having more than one cylinder so that the radial components of the forces are symmetrically balanced and the axis of the rotating cylinder is coaxial with the axis of the shaft of the motor, while the flywheel and rotor of the motor are made in one piece.
  • FIG. 1 is a longitudinal section through the device according to the invention.
  • FIG. 2 is a perspective view of the assembly comprising the rotor, the flywheel, the weight, and the driving member, shown in an exploded arrangement;
  • FIG. 3 shows the device according to the invention as seen from the rear, with the end closure and the air distributing disc removed;
  • FIG. 4 shows the air distributing disc
  • FIG. 5 shows the end closure
  • FIG. 6 shows the valve which may be operated from the outside and which makes it possible to reverse the direction in which the compressed air is supplied and consequently the direction of rotation of the motor;
  • FIG. 7 shows the air distributing disc for the piston which controls the translation of the mobile weight
  • FIG. 8 shows in plan view the cylinder in which the piston moves
  • FIG. 9 is a sectional view of the same cylinder taken along the line AA of FIG. 8;
  • FIG. 10 is a sectional view of the same cylinder taken along the line 3-8 of FIG. 8;
  • FIG. 11 is a sectional view of the same cylinder taken along the line C-C of FIG. 8.
  • reference numeral 1 indicates the casing which carries a pistol grip 2 and is closed at one end by a cap 3.
  • a drive member4 projects from 'the other end and which may, through any suitable tool, be brought in contact with the head of the screw or the bolt.
  • the handle 2 has a passageway 5 for admitting compressed air, which passageway may be opened or closed by valve 6 actuated by a trigger 7 and biassed closed by a spring 7a.
  • a duct 8 containing a felt 9 v soaked in oil intersects the passageway 5.
  • This passageway leads to a cylindrical chamber 10 having a transverse axis, best seen in FIG. 6.
  • a piston 11 is movable inside this chamber by means of pushbutton 12 and 13 (FIG.
  • the cylinder 10 also has exhaust ports 14a and 15a which are in communication with the chamber 16 in the casing.
  • the end member 3 which closes the rear end of the casing 1a has a passageway which leads to the orifice 14 and comprises a shallow groove 16a and a deeper duct 16b.
  • the groove 17a and the duct 17b which lead to the orifice 15 are formed in like manner in the end member 3.
  • the end member 3 and the casing 1 hold a distributor disc which has four front grooves 18, 19, 20 and 21 which lead to the ports 18a, 19a, 20a and 21a. These ports are positioned opposite the grooves in the end member as hereinafter described.
  • the port 18a is opposite the duct 17a; the port 20a is opposite the duct 17b; the port 19a is opposite the duct 16b; and the port 21a is opposite the duct 16a, so that the direction of the rotation of the rotor 22 is, in FIG. 3, clockwise when the piston 11 is in the position shown in FIG. 6.
  • the flow of air reaches the port 23 through the grooves 19 and 21, which holds the vanes 24 in their outermost position.
  • the casing 1 contains a cylinder 25 having an elliptical section inside of which the rotor 22, which is centered on the axis rotates.
  • This rotor carries a plurality of radially directed seats 26 in which the vanes 24 are carried.
  • the elliptical chamber has at'its apex a row of exhaust ports 27 which communicate directly with the exterior and, at its bottom, a row of exhaust ports 28 which communicate with the chamber 16 and, therethrough, with the exterior.
  • the rotor 22 has a peripheral groove 30 which is in direct communication with the air inlet duct through a duct 31. This groove 30 feeds a duct 32 which supplies the control means or the device which reciprocates the mobile weight 33.
  • this mobile weight comprises a star-shaped member having three radial arms 34 which are constantly engaged in three seats 35 in a fly wheel 36 which is cup-shaped and integral with the rotor 22.
  • the arms 34 each have a projecting portion which is adapted to contact one of the radial arms 4a projecting from the driving member or chuck of the machine when the mobile weight is forwardly projected.
  • This mobile weight 33 is attached to a tubular member 37 (FIGS. 9-11) which carries axially spaced flanges 38 which cooperate with the annular ring 39 to form a piston inside thecylinder 40.
  • the cylinder 40 is connected to the central shaft 41 by means of a pin 42 which passes therethrough, said shaft being connected at 41a to the drive member 4 so as to turn therewith.
  • the disc 53 Between the end of the cylinder 40 and the rotor 22 is a disc 53,- which is caused to rotate with the rotor by the key 54.
  • the disc 53 has an upper bore 43 which communicate with the duct 32 and a lower bore 44 at a different radial distance from its center, which communicates with a circumferential slot 45, which in turn communicates through the duct 46 with the chamber 16 and therethrough with the exterior of the machine.
  • the bore 43 and the bore 44 lead during the rotation of the disc 53 to the orifices 47, 48, 49, and 50, 51, 52 in one face of the cylinder 40.
  • the order in which the said orifices are reached depends upon the direction of the rotation of the rotor.
  • the orifices 47, 49 and 51 are the ends of three ducts 47a, 49a and 51a which open into one end of the cylinder 40 while the orifices 48, 50 and 52 are the ends of the ducts 48a, 50a and 52a which open into the opposite end of the cylinder 40.
  • the piston formed by the flanges 38 is forced forward and, together with the tubular member 37 and the mobile weight 33 which is fixed thereto.
  • the forward movement terminates when the movable mass 33 strikes the drive member or chuck 4 of the machine, which member received a torsional pulse in the same direction of rotation as the rotor 22.
  • a power screwdriver having a drive member and a coaxial pneumatic motor for driving said drive member
  • said motor comprises a plurality of chambers
  • said screwdriver comprises a rotor coaxial with said drive member and driven by said motor, a weight coaxial with said drive member mounted to be driven in rotation by said rotor but axially slidable with respect thereto, and pneumatic means for reciprocating said weight, comprising a piston chamber within said rotor, a piston within said piston chamber connected to said movable weight, and means for supplying air under pressure to said chamber on opposite sides of said piston alternately, said drive member and weight being provided with inter-engaging means through which said weight rotates said drive member when said weight is at one end of its axial path of travel, but which are disengaged when said weight is at the other end of its path of travel.
  • said pneumatic means also comprises a shaft connected to turn with said rotor and projecting into said piston chamber, a cylinder connected to rotate with said shaft and defining said piston chamber, passageways in said cylinder for admitting air to said piston chamber and for exhausting air from said piston chamber on opposite sides of said piston, and air supply and exhaust ducts in said rotor positioned to align with the passageways in said cylinder successively upon relative rotation between said rotor and cylinder.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Details Of Spanners, Wrenches, And Screw Drivers And Accessories (AREA)
  • Actuator (AREA)
  • Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
US00146030A 1970-05-25 1971-05-24 Pneumatic screwdriver Expired - Lifetime US3741314A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT4687370 1970-05-25

Publications (1)

Publication Number Publication Date
US3741314A true US3741314A (en) 1973-06-26

Family

ID=11260027

Family Applications (1)

Application Number Title Priority Date Filing Date
US00146030A Expired - Lifetime US3741314A (en) 1970-05-25 1971-05-24 Pneumatic screwdriver

Country Status (5)

Country Link
US (1) US3741314A (enrdf_load_stackoverflow)
JP (1) JPS5119200B1 (enrdf_load_stackoverflow)
DE (1) DE2124149A1 (enrdf_load_stackoverflow)
FR (1) FR2097803A5 (enrdf_load_stackoverflow)
GB (1) GB1354028A (enrdf_load_stackoverflow)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5836403A (en) * 1996-10-31 1998-11-17 Snap-On Technologies, Inc. Reversible high impact mechanism
EP1454714A3 (en) * 2003-03-07 2006-02-22 Ingersoll-Rand Company Rotary tool
US20140217306A1 (en) * 2013-02-01 2014-08-07 Bruno Ferran Split drive assembly and guide sleeves for uv disinfection modules
US20180117745A1 (en) * 2015-01-30 2018-05-03 Hitachi Koki Co., Ltd. Impact tool
EP3351723A1 (en) * 2017-01-20 2018-07-25 Yu-Jen Wu Pneumatic motor with dual air intake
US11285588B2 (en) * 2017-12-11 2022-03-29 Atlas Copco Industrial Technique Ab Electric pulse tool

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS52110443U (enrdf_load_stackoverflow) * 1976-02-18 1977-08-22
JPS5333800U (enrdf_load_stackoverflow) * 1976-08-30 1978-03-24
JPS6128895A (ja) * 1984-07-18 1986-02-08 日本原子力研究所 核燃料物質および特殊核分裂性物質監視装置
DE3503032C2 (de) * 1985-01-30 1994-04-07 Gardner Denver Gmbh Druckluftmotor für Druckluftschrauber
ATE329732T1 (de) 2000-01-27 2006-07-15 S P Air Kk Pneumatisches rotations-werkzeug
JP3746482B2 (ja) 2000-09-08 2006-02-15 エス・ピー・エアー株式会社 空気式ロータリツール
US6880645B2 (en) 2002-06-14 2005-04-19 S.P. Air Kabusiki Kaisha Pneumatic rotary tool
WO2015182512A1 (ja) * 2014-05-30 2015-12-03 日立工機株式会社 打撃工具

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5836403A (en) * 1996-10-31 1998-11-17 Snap-On Technologies, Inc. Reversible high impact mechanism
EP1454714A3 (en) * 2003-03-07 2006-02-22 Ingersoll-Rand Company Rotary tool
US20140217306A1 (en) * 2013-02-01 2014-08-07 Bruno Ferran Split drive assembly and guide sleeves for uv disinfection modules
US20180117745A1 (en) * 2015-01-30 2018-05-03 Hitachi Koki Co., Ltd. Impact tool
EP3251799A4 (en) * 2015-01-30 2019-02-13 Koki Holdings Co., Ltd. SHOCK WORKING MACHINE
US10654153B2 (en) * 2015-01-30 2020-05-19 Koki Holdings Co., Ltd. Impact tool
EP3351723A1 (en) * 2017-01-20 2018-07-25 Yu-Jen Wu Pneumatic motor with dual air intake
US20180209272A1 (en) * 2017-01-20 2018-07-26 Yu-Jen Wu Pneumatic motor with dual air intake
US10677060B2 (en) * 2017-01-20 2020-06-09 Yu-Jen Wu Pneumatic motor with dual air intake
US11285588B2 (en) * 2017-12-11 2022-03-29 Atlas Copco Industrial Technique Ab Electric pulse tool

Also Published As

Publication number Publication date
JPS5119200B1 (enrdf_load_stackoverflow) 1976-06-15
GB1354028A (en) 1974-06-05
DE2124149A1 (de) 1971-12-09
FR2097803A5 (enrdf_load_stackoverflow) 1972-03-03

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