US3012792A

US3012792A - Power driven pipe machine

Info

Publication number: US3012792A
Application number: US9267A
Authority: US
Inventors: Bengt G Bjalme
Original assignee: Reed Manufacturing Co
Current assignee: Reed Manufacturing Co
Priority date: 1960-02-17
Filing date: 1960-02-17
Publication date: 1961-12-12
Anticipated expiration: 1978-12-12

Description

Dec. 12, 1961 B. G. BJALME 3,012,792

POWER DRIVEN PIPE MACHINE Filed Feb. 17, 1960 2 Sheets-Sheet 1 I 40 I J jfilf 5 F LL 57 35 35 6 4/ w /4 1 Q 37 I 35 5 91 37 FIG. 4 /5 4 13 2? I 25 v /7 be 22 5:7

FICaJ 2/ INVENTOR.

Dec. 12, 1961 B. G. BJALME POWER DRIVEN PIPE MACHINE 2 Sheets-Sheet 2 Filed Feb. 17, 1960 IN E EN TOR. m.

United States Patentfiice Patented Dec. 12, 196 1 3,012,792 POWER DRIVEN PIPE MACHINE Bengt G. Bjalme, Erie, Pa., assignor to Reed Manufacturing Company, Erie, Pa., a corporation of Pennsylvania Filed Feb. 17, 1960, Ser. No. 9,267 Claims. (Cl. 279--114) This invention is a power driven pipe machine having torque energized pipe gripping jaws providing a controlled relation between the driving torque and the force with which the pipe is gripped.

In the drawing, FIG. 1 is a sectional side elevation, FIG.

21's a front view partly broken away, FIGS. 3 and 4 are views from opposite ends of the jaws, FIG. 5 is a section on line 5-5 of FIG. 1 and FIG. 6 is a section on line 6-6 of FIG. 2.

The machine has a frame 1 having on its under

side sockets

2, 3 for front legs 4 and a socket 5 for a rear leg 6 providing a stable three point support for the machine. On the rear of the frame is a motor 7 which drives a pinion 8 through reduction gearing 9. The pinion meshes with a gear 10 journaled on the frame by bearings 11, 12.

On the rear side of the gear 10 is fixed a pipe guide body 13 in the free end of which is screwed a guide plate 14 having radial slots 15 carrying pipe guide members 16. The guide members are moved in and out by a manually turned scroll plate 17.

On the front side on the gear 10 is bolted a drive plate 13. Between the drive plate and the gear is a scroll carrier 19 journaled on a shoulder 20 on the gear 10. On the scroll carrier are fiXed three symmetrically spaced segments 21 having an annular groove 22 therein rotatably receiving a scroll 23. The scroll is turned by a hand wheel 24 having three arcuate recesses 25 therein each receiving a projection 26 on the scroll. There is a lost motion between the recesses and the projections so that the hand wheel can impart a hammer blow to the scroll.

The scroll carrier 19 is connected to the drive plate 18 by three coil springs 27 arranged in

semi-cylindrical sockets

28, 29 respectively in the drive plate 18 and in each of the segments 21 fixed to the scroll carrier. The

sockets

28, 29 have semi-circular end surfaces or

seats

30, 31 which confine the springs. In the neutral or non-driving position, the

seats

30, 31 are in alignment. Upon relative rotation of the drive plate 18 with respect to the scroll carrier 19 in either direction, the springs 27 are compressed between the

end surfaces

30, 31. The springs 27 form a resilient driving connection from the drive plate 13 to the scroll carrier.

The sides of the segments 21 are spaced from each other and are undercut at 32 to provide a radial slot or guideway 33 between each pair of segments slidably receiving a jaw carrier 34-. On the face of the jaw carriers adjacent the scroll plate are teeth 35 which fit between the usual ribs 36 of the scroll plate. As the scroll plate is turned relative to the jaw carriers 34, the jaw carriers are moved radially in or out, depending on the direction of relative motion. On the face of each jaw carrier, remote from the scroll plate, is a pin 37 on which is pivoted a jaw 38 having at its inner end a toothed surface 39 for engaging the pipe and at its outer end a pin 40 rotatably received in a block 41 slidably in a radial guideway 42 in the drive plate 18. The

pins

37 and 40 are radially spaced from each other so that as the drive plate 18 turns relative to the scroll carrier 19, the jaws are pivoted about the pins 37 by a force a lied to the pin 40. This applies a gripping force proportional to the amount of pivotal movement of the jaw about the pivot pin 37. This additional force prevents slipping of the pipe under heavy load.

The gripping force of the jaws 38 on the pipe is made up of two components. First, there is the gripping force imparted by the tightening of the jaws 38 against the pipe by the hand wheel 24. This gripping force is substantial due to the gradual pitch of the scroll and is augmented by the hammer blow effect made possible by the clearance between the recesses 25 and the projections 26 on the scroll plate. The second component of the gripping force is proportional to the driving torque imparted to the drive plate 18 from the motor through the gear 10. Since this component of the gripping force is proportional to the driving torque, it increases with the torque and thereby prevents slippage of the pipe during heavy load.

The magnitude of the torque energized component of the pipe gripping force is controlled in part by the stiifness of the springs 27 and in part by the radial spacing of the pivot pins 37 and 4d. If the springs 27 were absolutely rigid, no relative movement between the drive plate 18 and the segments 21 could take place and there would be no additional pipe gripping force due to the driving torque. The torque energized component is limited to a safe value by projections 43 on the drive plate 18 received between stops 44 in the faces of the segments zl'adjacent the drive plate. In the unlocked position of the jaws, there is a clearance 45 between each end of the projections 43 and the adjacent stop 44. The clearance 45 is such that it is taken up when the jaws have pivoted the allowable amount. After take up of the clearance, the drive plate and scroll carrier are driven together without further relative rotation and the torque energized component of the gripping force does not increase with further increase in driving torque.

When the driving torque is released, the torque energized component of the gripping force disappears and the jaws may be easily unlocked from the pipe. The forces stored in the springs 27 assist in unlocking the jaws and return the jaws to the central positions.

In the use of the machine, the pipe is inserted through the guides 16 until the desired portion of the pipe comes opposite the toothed gripping surfaces 39 of the jaws. The guide fingers are manually tightened against the pipe by turning the guide scroll 17 thereby steadying the pipe in the guide body 13. The jaws 38 are manually moved against the pipe by turning the hand wheel 24. A considerable gripping force is exerted by the jaws due to the very gradual pitch of the scroll 36 and to the supplemental hammer blow eifect. The pipe tool is then applied to the pipe and the motor 7 is started. The pipe tool, which may, for example, be a pipe threader, requires a considerable torque. It is held stationary, for example by a suitable stop on the frame of the machine, and the pipe is turned by the gear 10. The guide body 13 turns with the gear so there is no relative rotation between the pipe and the guide members 16. However, resistance to turning of the pipe relative to the pipe tool results in a retarding force at the toothed surfaces 39 of the jaws which causes relative rotation between the drive plate 18 and the segments 21 resulting in a compression of the springs 27, producing a relative movement between the drive plate 18 fixed to the gear 10 and the segments 21 between which the jaw carriers 34 are guided. The relative movement causes the jaws 38 to pivot about pins or fulcrums 37 on the jaw carrier 34 and to force the teeth against the pipe with a force proportional to such movement. At the end of the operation, the motor is stopped and the jaws unlocked by the hand wheel 24 assisted by the springs 27. The hammer blow effect is available to assist in unlocking the jaws. The jaws are easy to lock in non slipping engagement with the pipe, even under the heaviest loads, and are equally easy to unlock.

What is claimed as new is:

1. In a power driven pipe machine, a driving member, a driven member rotatable relative to the driving member, spring means for yieldably resisting relative rotation between the members, a scroll plate rotatably carried on the driven member, a radially extending guide in the driven member, a jaw carrier in said guide having teeth engaging the scroll to move the jaw carrier radially as the scroll is rotated relative to the driven member, a jaw having a pipe engaging surface, a fulcrum for the jaw on the jaw carrier spaced from the pipe engaging surface, and a connection between the jaw and the driving member radially spaced from the fulcrum and from the pipe engaging surface for pivoting the jaw about the fulcrum in proportion to the relative rotation between the members.

2. Ina power driven pipe machine, a driving member, a driven member and a scroll member rotatable relative to each other, spring means for yieldably resisting relative rotation between the driving and driven members, a radially extending guide, a jaw carrier in said guide having teeth engaging the scroll member to move the jaw carrier radially as the scroll member is rotated relative to the guide, a jaw, a fulcrum on the jaw carrier for the jaw, and means for pivoting the jaw about the fulcrum in proportion to the relative rotation between the driving and driven members.

3. In a power driven pipe machine, a driving member, a driven member and a scroll member rotatable relative to each other, opposed tangentially directed spring seats on the driving and driven members, a compression spring between said seats yieldably resisting relative rotation between the driving and driven members, a radially extending guide, a jaw carrier in said guide having teeth engaging the scroll member to move the jaw carrier radially as the scroll member is rotated relative to the guide, a jaw, a fulcrum on the jaw carrier for the jaw,

and means for pivoting the jaw about the fulcrum in proportion to the relative rotation between the driving and driven members.

4. In a power driven pipe machine, a radially extending guide, a scroll member rotatable relative to the guide, a jaw carrier in said guide having teeth engaging the scroll to move the jaw carrier radially as the scroll is rotated relative to the guide, a jaw having a pipe engaging surface, a fulcrum for the jaw on the jaw carrier spaced from the pipe engaging surface, a connection to the jaw radially spaced from the fulcrum and from the pipe engaging surface, and means for applying a force to said connection proportional to the torque load on the aws.

5. In a power driven pipe machine, a driving member, a driven member rotatable relative to the driving member, cooperating normally disengaged stop means on said driving and driven members coming into engagement upon a predetermined relative rotation between said members to limit such relative rotation, a scroll plate rotatably carried on the driven member, a radially extending guidc in the driven member, a jaw carrier in said guide having teeth engaging the scroll to move the jaw carrier radially as the scroll is rotated relative to the driven member, a jaw having a pipe engaging surface, a fulcrum for the jaw on the jaw carrier spaced from the pipe engaging surface, and a connection between the jaw and the driving member radially spaced from the fulcrum and from the pipe engaging surface for pivoting the jaw about the fulcrum in proportion to the relative rotation between the members.

References Cited in the file of this patent UNITED STATES PATENTS