US3354862A - Means for marking objects - Google Patents

Description

Nov. 28, 1967 w. F. FRANZ MEANS FOR MARKING OBJECTS Filed March 16, 1965 INVENTOR WILL IAM Ff FRANZ aywflw Attorney United States Patent OfiFice 3,354,862 MEANS FOR MARKING OBJECTS William F. Franz, Green Tree, Pa., assignor to United States Steel Corporation, a corporation of Delaware Filed Mar. 16, 1965, Ser. No. 440,086 1 Claim. (Cl. 118-8) ABSTRACT OF THE DISCLOSURE This invention relates to the marking of objects with colored wax or other compositions which leave a nondestructive mark on a surface. More particularly, this invention relates to an apparatus for marking objects, such as steel strip or pipe, to identify places where defects are detected in these objects.

The marking of an object by a means which will not abrade or scratch the surface of the object has long been a problem. If paint or chalk is used, such materials are quite likely to be picked up by apparatus which handles the object in subsequent operations, and this apparatus in turn redeposits the marking material on other parts of the object where marks are not desired. Unwanted marks are also transferred from one surface to another when the object is in the form of strip that is subseqently coiled after marking, or when the objects are bars or pipes which are gathered together into bundles after being marked. In addition to the foregoing, a special problem with many marking materials, especially paint, is that they will not adhere to wet or oily surfaces.

In the past, sticks of colored wax or crayons have been used to mark objects, but they too have presented problems. The marks left by the crayons are often so poor that they are diflicult to find, and the crayons break easily when great pressure is applied to improve the quality of the mark. Wet or oily surfaces have also been diflicult to mark with crayons.

It has been found that the above described difficulties of marking with colored wax and other materials can be overcome by applying the marks with the edge of a wheel that is mounted on a rotating shaft. By use of such a wheel with the method and associated apparatus to be described, the objective of marking an object with a clear, durable mark is accomplished.

This and other objects will appear more readily from the following detailed description of my invention and the attached drawings in which:

FIGURE 1 is a plan View of apparatus for marking objects; and

FIGURE 2 is a side view of the apparatus of FIG- URE 1.

As shown in the drawings, a pipe P is supported on table rollers 2, mounted on frame 3. An inspection device 4, held above the pipe by apparatus 5, inspects the pipe for defects. At the side of the pipe P is mounted a marking wheel 6.

The hub of the marking wheel 6 is fixed to a shaft 8 that is rotatably supported in bearing member 10. This bearing member is in turn welded to the end of a lever arm 12 that is best seen in the top view of FIGURE 1. The lever arm 12- is pivotally connected by pin 14 to a bracket support 16, and is normally maintained in a position such that the periphery of the marking wheel 6 3,354,862 Patented Nov. 28, 1967 is held a short distance from the surface of the adjacent pipe P, as shown in FIGURE 1.

To control the position of the marking wheel 6 and push the wheel against the pipe P, an air cylinder 18 is pivotally connected to the bracket 16 at pin 20. A springloaded piston in the cylinder 18 is attached to a rod 21, and pin 22 pivotally connects the rod 21 to the lever arm 12. The spring-loading of the piston in cylinder 18 maintains the wheel 6 normally away from the surface of the pipe P.

An air hose 23 connects the cylinder 18 to a compressed air supply 24. The air supply to the cylinder is controlled by a solenoid valve 25 in the hose 23. The valve 25 is in turn operated by an electric signal that is sent from the inspection device 4 whenever a defect is detected in the pipe P.

A motor 26, mounted on the supporting frame 3, is connected to the shaft 8 by a flexible shaft 28, and thus provides means for rotating the marking wheel 6. If desired, the motor 26 may be mounted on the end of the arm 12 to obviate the need for the flexible shaft 28. The motor 26 may be either electrically powered or driven by compressed air. The compressed air motor is preferred where the inspection device 4 produces a magnetic field which would interfere with the operation of an electric motor.

In operation, the pipe P is moved over the table rollers 2 in the direction of arrow a (FIGURE 1). When the inspection device 4 detects a defect in the pipe P, a signal is sent to the solenoid valve 25 causing it to open. This releases compressed air from the air supply 24 into the cylinder 18, and causes the piston in the cylinder to push the marking wheel 6, being rotated by the electric motor 26, against the surface of pipe P. The friction generated by the rotating wheel 6 rubbing against the pipe softens the marking material on the edge of the wheel. If the speed of the marking wheel is proper for the type of surface being marked, some of the marking material will be rubbed onto the pipe surface, leaving a durable mark that will not easily rub off. When the inspecting device 4 stops sensing the defect in the pipe, the solenoid valve will close off the air supply to the cylinder 18, and the spring-loaded piston therein will retract the wheel 6 to its original position away from the pipe.

It should be noted that the wheel 6 is mounted a short distance ahead of the inspection device 4, in the direction of travel of pipe P (arrow 1), to allow for the time delay between the sensing of a defect by the inspection device and the pushing of the marking wheel against the pipe P.

The speed at which the marking wheel 6 is rotated will depend upon the condition of the surface that is to be marked and upon the composition of the marking material that is used. For instance, most crayon marking materials will leave a good mark on smooth, dry surfaces when the wheel is rotated at a peripheral speed of as low as two feet per minute. However, much higher peripheral speeds are necessary to adequately mark smooth, oily surfaces, and the speed of the marking wheels periphery relative to the surface to be marked should be at least 500 or 600 feet per minute for these surfaces. At slower speeds, even extremely soft waxes applied at high pressures will not satisfactorily mark a smooth, oily surface, because large amounts of oil will be absorbed by the wax. The resulting mark will be one that is easily rubbed off during handling or storage.

While the quality of the marks will vary with the composition of the marking material, good marks can be obtained with most crayon waxes, provided the marking wheel is rotated fast enough. One composition of marking material that has been found to leave particularly good V marks contains silica, 1% iron oxide, 3% alumina, 1% magnesia, 35% titanium oxide, 50% paraffin wax, and 5% organic coloring agent.

The entire wheel 6 may be made of the particular marking material used, or this material may be confined to the outer edge portion of the wheel. In the latter case, the hub of the wheel would be composed of some other material, and could be constructed either as a solid disc or as a spoked wheel.

While one embodiment of my invention has been shown and described, it Will be apparent that adaptations and modifications may be made without departing from the scope of the appended claims.

I claim:

Apparatus for marking an elongated object having a hard surface to indicate places where defects occur in said surface, said apparatus comprising:

roller supports for carrying said object,

means for moving an object lengthwise over said roller supports,

a bracket member mounted adjacent the path of said object surface,

a lever pivotally connected to said bracket member,

a shaft rotatably mounted on said lever,

a wheel fixed to said shaft so as to rotate with the shaft, said wheel having a periphery of greater diameter than said shaft, said periphery being composed of a depositable marking material,

a motor connected to said shaft for rotating the shaft and wheel,

an air cylinder connected to said lever so that when actuated, said air cylinder moves said lever to bring said periphery of said rotating wheel into a sliding frictional, non-penetrating contact with said hard surface of said object,

means for detecting defects in said object surface, said means mounted adjacent the path of said object surface,

an air supply line connected to said air cylinder and having a valve for opening and closing said line, and

a solenoid operating said valve and connected to said means for detecting defects in said object surface, so as to cause said valve to open and said air cylinder to be actuated in response to the detection of a defect in said object surface.

References Cited UNITED STATES PATENTS 2,342,474 2/1944 Klein et al. 118-9 X 2,418,804 4/1947 Hood 118-76 X 2,997,017 8/1961 Steele 11877 X CHARLES A. WILLMUTH, Primary Examiner.

R. I. SMITH, Assistant Examiner.

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