Background of Invention
1. Field of Invention
Gauges.
2. Prior Art
Heretofore gauges have been provided for testing cylindrical objects for out-of-roundness, dimensional accuracy, and surface deformations. Typical of these prior gauges is an elongated base block with a pair of jaws elongated endwise of the base block and divergent from a point within the base upwardly to and through the upper face of the base. The faces of the two jaws are planar. A cylindrical article can be laid between the jaws and supported thereby in a non-tilting relation and rotated about its axis and shifted endwise while so supported. The base carries a conventional post on which a feeler type dial gauge is supported with its feeler in contact with the periphery of the article. The article is then slid endwise of the base to different positions and there rotated about its axis to check roundness and dimensional accuracy and the like of its circumferential surface at different locations along its length. There is no means for holding the article in a fixed position endwise of the base or jaws, and no end stop having a planar gauging surface normal to the axis of the article. Accordingly its field of application is limited.
Summary
In the present gauge, the base is preferably a flat, relatively thin block machined on one face to provide one or more under surface areas which define a plane and which, in the horizontal position of the plane, can engage and slide along the horizontal planar gauging face of a conventional granite gauging block to various locations and support the base in fixed annular relation to the plane of the gauging face of the block in all of said locations. The base has a V-slot which, endwise of its axis, extends endwise of the base through and from the under face and to and through the upper face of the base. The V-slot is defined by planar side wall faces which, beginning near the lateral midportion of the base, diverge from each other to, and open through, one edge of the base. The faces defining the V-slot are planar and preferably are at a right angle to the plane defined by the under surface of the base. Supporting posts are detachably mounted on the base for supporting dial indicators in positions in which they can engage the periphery of an article at its upper end or on its laterally exposed wall surfaces while the lower end of the article rests on the granite block, and that portion of the circumferential wall of the article, at a location closely adjacent the lower end of the article, is juxtaposed against the two positioning jaw faces of the V-slot. As a result, the gauge can be manipulated to gauge, concurrently, the following: the angular relation of the ends of the article relative to each other and to the axis and circumferential walls of the article; centricity and dimensional accuracy of internal and external diameters of annular articles; the endwise taper of the circumferential wall of frusto-conical or spherical articles, and the like. These gauging operations can be effected concurrently simply by placing the article with its circumferential wall, at a location closely adjacent its lower end, in engagement with the faces of the V-slot, and with its lower end resting on the granite block, and rotating the article while it is held in this position.
Other objects and advantages will become apparent from the following description wherein reference is made to the drawings.
Brief Description of the Drawings
FIG. 1 is a perspective view of a preferred form of a gauge embodying the principles of the present invention;
FIG. 2 is a top plan view of the gauge illustrated in FIG. 1;
FIG. 3 is a cross sectional view of the gauge taken on the line 3--3 of FIG. 2;
FIG. 4 is a right side elevation of the gauge illustrated in FIG. 2;
FIG. 5 is a top plan view of a modified form of a gauge; and
FIG. 6 is a right side elevation of the gauge shown in FIG. 5.
Referring to the drawings, the gauge comprises a base, indicated generally at 1, which preferably is in the form of a flat metal block having its under face 2 machined or ground precisely to provide a planar supporting surface, or a plurality of spaced surface areas which, together, define a planar supporting surface, by which the block can be supported on the planar upper gauging face of a conventional granite gauge block 3 and can be slid about thereon to preselected locations while maintaining a fixed angular relation to the gauging face of the granite block. The base 1 is provided with positioning jaws 4 and 5 which preferably are the sides of a V-slot 6 which extends endwise of the base 1 from and through the under face 2 to and through the upper face of the base 1. The jaws extend from a small central bore 7 in divergent relation to each other in a direction outwardly to and through one side of the base 1. The faces 4a and 5a of the jaws 4 and 5, respectively, are lineal from their inner to their outer ends, and preferably are planar and normal to the plane defined by the planar supporting surface at the under face of the base 1, or to the face of the granite block 3 when the base 1 is resting thereon. The faces 4a and 5a of the jaws 4 and 5 preferably diverge from each other at 90.degree..
Thus, as illustrated in FIG. 1, an article A of circular cross section, at least near one end, may be stood on that end on the granite block 3 and the base 1 then slid theretowards so as to engage the circumferential wall of the article A, near that end, at two circumferentially spaced locations thereon. The article A is thereby positioned in a fixed lateral position with its axis on the line bisecting the 90.degree. angle between the faces 4a and 5a of the jaws 4 and 5. In this position, assuming the article A is a frusto-conical annulus as illustrated, the article A is in a position for gauging the squareness or angular relation of the ends relative to the axis and circumference of the article, and to each other, and for gauging the internal and external diameters for dimensional accuracy, out-of-roundness, and centricity of both the internal and external diameters and surfaces.
For this purpose, the base 1 is provided with a plurality of detachable posts, such as the posts 10, 11 and 12, each of which extends upright normal to the planar supporting under surface of the base 1. Each of the posts carries a conventional dial gauge, such as indicated at 13, having a feeler 14 for engaging the surface to be gauged. As is conventional, each of these indicators is carried on a stem 15 having pivoted clamps 16 by which it can be supported on the post, such as the post 12, in preselected adjusted positions vertically of the post, circumferentially of the post, and in tilted relations thereto. Thus a number of indicators can be placed with their feelers in operative contact with different portions of the article concurrently, and used for indications while the lower end of the article rests on the gauging surface of the granite block 3 and the circumferential wall of the article, near the bottom of the article, engages the faces 4a and 5a of the jaws 4 and 5. In the illustrative example, one indicator is placed with its feeler on the upper end surface of the article A, as indicated at 17, another with its feeler on the internal bore wall, as indicated at 18, and another with its feeler on the external circumferential wall, as indicated at 19. With the indicators thus positioned, the article can be rotated and any discrepancies in the angular relation of the ends, sides, and external and internal diameters, and in the centricity of the circumferential walls, and the axis of the article, and out-of-roundness and the like, and readily be detected.
In some articles, such as the article A illustrated, it is desirable that the feeler of one of the indicators be placed against the circumferential wall as near to the bottom of an article as possible. To facilitate access to this wall portion, the upper surface 9 of the base 1, as indicated at 20, is tapered, from a point near the posts toward the opposite edge or open side of the V-slot at an angle of about 7.degree., or possibly more, to the plane of the under face, depending upon how close to the bottom end of the article the circumferential surface of the article A is to be tested. Thus one can gauge concurrently the parallelism and angular relation of the upper end of the article A relative to the bottom end, the angular relation of the ends to the circumferential surfaces, the squareness of the ends relative to the longitudinal axis of the article, the endwise slope of frusto-conical surface, the out of roundness and dimensional accuracy of the internal and external walls, and the centricity of the various surfaces of revolution, external and internal diameters.
In effect, the granite block supplements the V-type positioning jaws by acting as an end stop which holdes the article in fixed position axially or endwise relative to the jaws and further maintains the lower end of the article, which usually is intended to be normal to the axis of the article, in the fixed plane of the gauging face of the gauge block 3 during rotation of article about its axis while in contact with the jaw faces 4a and 5a.
Referring next to FIGS. 5 and 6, a like gauge to that of FIGS. 1 through 4, is illustrated, its base block being indicated at 21. The only difference from the structure of FIGS. 1 through 4 is that, instead of the under face of the base 21 being a continuous planar face, the under face is machined or ground to provide feet, as indicated at 22, 23 and 24, which have bottom faces lying in a common plane disposed slightly below the remainder of the under face of the base block 21. Preferably three such feet are employed, thus providing a "three-point" support for the base.
In the disclosure and claims, the under or bottom surface of the base or block is described as planar, and this wording applies to both forms of the invention.