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
  • B25B13/00—Spanners; Wrenches
  • B25B13/10—Spanners; Wrenches with adjustable jaws
  • B25B13/28—Spanners; Wrenches with adjustable jaws the jaws being pivotally movable
  • B25B13/32—Spanners; Wrenches with adjustable jaws the jaws being pivotally movable by cam, wedge or lever
• • 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
  • B25B13/00—Spanners; Wrenches
  • B25B13/48—Spanners; Wrenches for special purposes
  • B25B13/50—Spanners; Wrenches for special purposes for operating on work of special profile, e.g. pipes
  • B25B13/5008—Spanners; Wrenches for special purposes for operating on work of special profile, e.g. pipes for operating on pipes or cylindrical objects
  • B25B13/5016—Spanners; Wrenches for special purposes for operating on work of special profile, e.g. pipes for operating on pipes or cylindrical objects by externally gripping the pipe
  • B25B13/5025—Spanners; Wrenches for special purposes for operating on work of special profile, e.g. pipes for operating on pipes or cylindrical objects by externally gripping the pipe using a pipe wrench type tool
  • B25B13/5041—Spanners; Wrenches for special purposes for operating on work of special profile, e.g. pipes for operating on pipes or cylindrical objects by externally gripping the pipe using a pipe wrench type tool with movable or adjustable jaws
  • B25B13/505—Pivotally moving or adjustable

Definitions

• the invention relates to a pipe wrench .
• Self-tightening tongs and wrenches consisting of two linked parts , one of which has a shank and handle , have been known for many years .
• these wrenches are designed so that the shank part has a jaw which - when viewed from the side - is limited by a circle or a curve with a variable curvature , while the jaw face of the other part can be plane or consist of pl anes forming angles to each other ; for example , so that the jaw fits hexagon nuts .
• Wrenches most often bear the stamp of the curved jaw limit of the shank part being a compromise which does not hold equally well on to all nut sizes or pipe diameters within the ranges accomodated by the wrenches .
• the curvature of some wrenches has been designed by determination of a few usable points through which the curves have been drawn .
• the pipe wrench according to the invention is characterized in that the centre in the shank part for the relative rotation of the parts is also the centre of a circle , the involute of which forms the exact limit of the jaw of the shank part .
• a study of line 1 of the side view ( a delineation of a plane at right angles to the axis of rotation ) , which line is normal to the jaw face of the other loose jaw part or is an angle bisector relative to two of the jaw faces of the part, shows that because of the involute all the pipes of the diameters accomodated by the wrench contact the involute exactly where it is intersected by line 1 when the centre of rotation of the loose jaw part is at a distance from 1 which is radius of the circle belonging to the involute .
• the point of contact can be moved a small distance ⁇ r tangentially in the direction of rotation by the centre of rotation of the loose jaw part being moved the distance ⁇ r closer to 1 when 1 is angle bisector relative to two jaw faces forming an angle of 60° to each other in the loose jaw part .
• the wrenc h works in the way that pipes or parts inserted between its jaws are firmly fixed between these when the handle is pulled , and they are at the same time actuated by a moment.
• the normal force K between pipe and jaw is determined by the moment of the shank and the moment arm r which is the same for all pipe diameters as a result of the inv olute design .
• the loose jaw shall be V-shaped with 60° between the sides to which 1 is the angle bisector since the actuated pipe will then receive the normal force K at three points at 120° intervals which partly reduces the risk of flattening and partly permits transmission of a moment which is 50 p . c . higher as compared to a design where the normal force K acts at two points on the pipe at intervals of 180° .
• the wrench will also be suitable for hexagonal parts , and as mentioned in the foregoing the point of contact and hence the line of application of the force K can be moved a distance ⁇ r tangentially in the direction of rotation which , when ⁇ r is small , does not change the fact to any considerable degree that parts are actuated at three points at 120° intervals since, in actual practice , these "points" are faces of a size of a few millimetres .
• the wrench can be provided with adjustment facilities since a possible shifting in the direction of line 1 on the loose jaw of its axis of rotation will extend the diameter range covered by the wrench .
• FIG. 1 shows the wrench seen from one side and gripping a heavy pipe
• Fig. 2 shows the wrench seen from one side and gripping a thin pipe
• Fig. 3 shows the wrench in perspective.
• the wrench consists of a shank with an involute, possibly a toothed, jaw a and a loose jaw b pivotally connected hereto.
• Fig. 1 shows the radius r of the circle c belonging to the involute as well as r, 1, and K mentioned in the foregoing.
• Fig. 4 shows a design where the concave side of the involute is utilized as a jaw curve for the shank.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Details Of Spanners, Wrenches, And Screw Drivers And Accessories (AREA)
• Shearing Machines (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8137949

Family Applications (1)

Country Status (4)

Cited By (4)

Citations (6)

Family Cites Families (3)

• 1980
  • 1980-11-20 DE DE8080902284T patent/DE3068462D1/de not_active Expired
  • 1980-11-20 WO PCT/DK1980/000074 patent/WO1981001385A1/en not_active Ceased
  • 1980-11-20 EP EP80902284A patent/EP0040231B1/en not_active Expired
  • 1980-11-20 JP JP50012580A patent/JPS56501639A/ja active Pending

Patent Citations (6)

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