US2403420A - Protractor for pipe bending machines - Google Patents

Description

July 2, 1946. N WHLUNGHAM' zmmm PROTRAC'IOR FOR PIPE BENDING MACHINES Filed Feb. 24', 1944 FITTURNEY Patented July 2, 1946 PROTRACTOR FOR PIPE BENDING MACHINES Elijah N. Willingharn, Santa Rosa, Calif.

Application February 24, 1944, Serial No. 523,759

1 Claim. 1

This invention relates to improvements in protractors for pipe bending machines.

The principal object of this invention is to provide a protractor for determining the degree of bend for a pipe being bent in a standard pipe bending machine.

A further object is to produce a device of this character which may be attached to any standard pipe bending machine.

A further object is to produce a device of this character which is simple in construction, cheap to manufacture and easy to apply to any machine.

A further object is to produce a device of this character which may be readily adjusted and one wherein the parts may not be readily deranged.

Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawing forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Fig. I is a top plan view of my device as the same appears in use.

Fig. II is a view similar to I showing the device after a ninety degree bend has been made, and

Fig. III is a cross sectional view taken on the line 3-3 of Fig. II.

In bending pipe the pipe is usually held in a pipe bending machine which comprises a forming die and holding jaw and a movable jaw, the movable jaw being power driven, and as it moves along the outside of the pipe, it bends the pipe around the forming die, the result being that the pipe is bent to any desired degree or angle.

' Heretofore it has been necessary to stop the machine and use straight edges, angles, etc, to try to determine the degrees to which the pipe has been bent. This was a very difficul't operation and consumed considerable time There is also inherent in the pipe certain resiliency, so that when the machine stops the pipe springs back a few degrees, and itis then necessary to bend it a few more degrees, in order to come up to the desired degree of bend.

Applicant has devised a .protractor-like arrangement, which may be attached to the top of the standard machine, which prom-actor has an arm carrying a roller which engages the side of the pipe and by setting the protractor at a zero point and then bending the pipe the exact degree of bend can be readily determined; also, the degree of over-bend to take care of the springback can also be determined, which enables the user to produce bend after bend of exactly the 2 same number of degrees. This is particularly important in ship construction work where complicated bends of a definite number of degrees must be made.

In the accompanying drawing wherein for the purpose of illustration is shown a preferred embodiment of my invention, the numeral 5 designates the base of a machine which supports the forming die 6 upon a stub shaft '1. The pipe 8 is held against the forming die by a holding jaw 9.

A movable jaw is shown at l I, which moves in the path shown by the arrow A.

The parts thus far described are common to all bending machines.

My inventioncomprises a protractor I2, which is secured to the shaft 6 by a bolt l3, and an arm !4, rotatable about the stub-shaft l and supported upon a collar l6, resting upon the top of the forming die 6. The arm M carries a pointer II which moves over a scale formed on the protractor l2. A roller 28 is slideably mounted on the arm M, and is adapted to lie against the side of the pipe 8.

The result of this construction is that when the pipe is positioned in the machine, as shown in Fig. I and the roller it is brought against the side of the pipe, bolt 13 is loosened and the protractor is rotated until it registers zero with the pointer ll; then the bolt I3 is locked.

The machine is now started so that the movable jaw moves in the direction of the arrow A and causes the pipe to be bent around the forming die 6. The roller ill will be forced around from a position in Fig. I to that in Fig. II, when a ninety degree bend is being made, and the operator can then watch the pointer until it has arrived at the ninety degree mark or a predetermined numbered degrees beyond to take care of the springiness in the pipe.

As the roller always bears the same relation to the pipe, it is immaterial Where the roller is positioned against the pipe as long as the pointer and the zero degree marl: are set when the operation first commences.

It will thus be seen that I have provided a device which will perform all the objects above set forth and one which is positive in determining the amount of bend of a pipe being worked upon.

It is to be understood that the form of my invention herewith shown and described is to be taken as a preferred example of the same and that various changes relative to the material, size, shape and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claim.

engaging said pipe and adapted to bend a portion of said pipe about said die and an arm carried by said protractor, said arm having a roller engaging the side of said pipe next to said die and at a point always tangent to the face of said forming die projected from a point where the movable jaw faces the die.

ELIJAH N. WILLINGHAM.

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