US2372494A - Inspection and layout apparatus - Google Patents

Description

March 27, 1945. J. H. I-IIOGAN ETAL 2,372,422

INSPECTION AND LAY-OUT APPARATUS Filed Oct. 2, 1942 2 Sheets-Sheet l Inventors: John H. Hogan. Clarence J. Kettler, Forrest H. Judkins,

Theodore W. Hall,

by Their Attorney Ma'rch 1945. J HOGAN ETlAL' 2,372,494

INSPECTION AND LAY-OUT APPARATUS Filed Oct. 2, 1942 2 Sheets-Sheet 2 Fig.3. Y

- Inventors:

John HHOgan, Clarence J. Kettler, Forrest H. Judkins,

Theodore W. Hall,

y TPfZiZAttorney Patented Mai. 2-7, 1945" 2,372,494 INSPECTION AND LAYOUT ArrAr A'rUs ohn H. Hogan, Clarence J. KetueryForrest H. Judkins, and Theodore W. Hall, Pittsfleld,

Mass 'assignors to General Electric a corporation of New .York

Company,

Application October 2, 1942, Serial No. 460,514

5 Claims (01. 88-24) In the laying out of machine castings preparatory to the machining of variou parts thereof a common practice has been to lay out the surfaces and centers of parts to be machined with the casting resting upon a; surface plate. The laying out operation would begin at some chosen point and proceed therefrom according to the dimensions prescribed by the drawing or'print being followed. After the machining of the casting had been completed it not infrequently was found that the walls of the casting were decidedly thicker at one side of the castingthan' at the other or that the exterior'surface of a boss was noticeably eccentric to the machined inner surengaged in the lay-out work make various partial or preliminary lay-outs starting from different points of the casting and then after comparing with the accompanying drawings and its scope willqbe pointed out in the appendedclaims.

Referring to the drawings, Fig. 1 isa perspective view of a form of apparatus embodying ourinvention and Figs. 2 and 3 are circuit diagrams. Referring to Fig. 1 an article to be inspected and laid out is represented at I which article may be constructed by casting, by fabricating or in any other manner.

' the turntable 2 by suitable adjustable means the results of theseveral lay-outs adopting one I of them or a modification thereof as the'one best adapted to give the desired uniformity. Such a procedure is not only time consuming, hence expensive, but in-th'e case of large quantity production requires the services of many skilled worlnnen.

It is the object of our invention to provide improved apparatus which facilitates the inspection and the laying-out in a desired manner of three dimensional articles such as castings where'bythe time and labor required are greatly reduced.

In accordance with our-invention, briefly, we'

provide: a support for the article to be inspected and laid out which support may be, adjustable in various directions and rotatable; a projector under face spaced 45 apart for convenience in such as the three jacks 3. The apparatus by which the turntable is mounted permits the operator readily to adjust the height and lateral position of the turntable. This apparatus, as shown by the drawings, comprises the cross head 4 which slidesin the vertical guides 5 and is raised and lowered by means of'the three phase motor 6 operating through theworm gearing i,

the shafts 8, and the chains 9 whichlatter connect with the cross head. The running of the motor and the reversal thereof is controlled by the switch in. The bearing 62 of the turntable pivot shaft is slidable laterally in, the guides l3 forming a part of the cross head 4 and is arranged to be adjusted by the. hand operated screw I5. The turntable is provided with notches IS in its the casting ..-is represented at 20. It is of wellknown constructiqn egceptthat it is arranged to be moved bodily 'towardand from an article on the turntable and has a special slide holder and operating mechanism therefor. The-projector is supported as a whole on the guides 2| which extend toward the turntable and is caused to move thereon by the motor 22 acting through the worm gearing 23 and 24, the pinion 25, and the rack 26 fi'ire'd to the projector. The slide carrier 2! means with reference to thearticle while malntaining a fixed distance therebetweem Our invention will be better understood from the following description taken inconnection is or special form being constructed to receive several slides or transparencies, six in'the present case, shown at 28, 29, etc. These slides are photoraphs of drawings 01' various faces or surfaces Inasmuch as we have used our invention-more extensively in connection with 1 cast articles and in view of the apparent absence of the casting showing those faces or surfaces ata definite reduced scale as they should appear when machined. They also include cross lines showing the centers of any holes that are to be bored. It is to be understood that in Fig. 1 the slide in projecting position is the one showing that face of the casting which then is turned toward the projector and that the vertical and horizontal cross lines at the five bolt holes 3| and the base line 32 are line; being projected in the casting from that s1ide,the pnijector being focused on the face 33 of the casting. While the operator observes the casting in partial darkness with the image projected thereon'he adjusts the vertical and horizontal position of the turntable by the means described above until the casting is made to occupy the desired position with reference to the image cast upon it. By means of the scribing tool 35 he may scribe a base line on the casting corresponding to the projected line 32 and he may also scribe cross lines for the holes 3! guided by the projected cross lines. Should the casting have a face or part such as the boss 35 which is located in a plane in front of or behind the plane of the face 33 the projector will of course be refocused iii-that face or part before it is inspected and laid out. The particular means which we have devised for readily determining the location of the focal plane of the projector will be described later. The inspection and laying out operation having been completed for that face of the casting the turntable is rotated to bring another face in position before the projector but without changing the elevation. For making an inspection or lay-out on each different face of the casting or on each different plane thereof a different slide is moved into pro-'- jecting position. We shall now describe how from a remote point of control one may bring the particular slide desired into projecting position.

drum switch there being one switch 45 for each slide. The drum of the drum switch has a metallic face in two parts 41 and 48 separated by the insulating strip 49 extending spirally therebe-- p rases.-

becomes desirable that theoperator be provided with some means of quickly and accurately locating the focal plane of the projector. We shall now describe that feature of our invention which facilitates the rapid and accurate relative positioning of the projector and the article to be inspected and laid out. We indicate the location of the focal plane of the projector by means of a thin, sheet-like light beam which is projected in a direction at right angles to the axis of projection and positioned at the focal distance from the projector. The lightbeam which is indicated by the dot and dash lines 56 is projected by the projector 51 and has its focal point slightly above the turntable 2. Such a projector may, for example, have a very narrow light slit which is arranged to be imaged at the aforesaid focal point. This projector preferably is positioned to project its focal plane indicating beam 01' wand" in a downward direction and to conserve space may be arranged horizontally as shown by the drawing with a light reflector, such as the mirror 53, interposed in the path of the light beam. The projector and the mirror are supported in a fixed relative position by the frame 59 which is movable horizontally in the same direction as the projector 20 being supported by the tracks 80 and the racks-6|. When the apparatus is used in a dark or semi-dark room the narrow light beam or wand" projected by the projector 51 may readily be seen where it shines upon the tumtable or the casting supported thereon. In the drawings it is represented as shining upon the casting at the top edge 62 of the front face 32, portions of the beam which spill over at the sides of the article showing at 63 on the turntable. When the main projector 20 is moved toward or from the casting to project images onits various faces or surfaces the thin light beam which indicates the position of the focal plane must move exactly with it. This movement is brought about by the use of a system for the transmission of angular motion comprising transmitting and receiving devices of the alternating current type such, for example, as ,is disclosed in U. S. Patents 1,6l2,li7 and 1,637 039. The projector 51 and the mirror 5% are moved by the receiving device 65 of such a system which. through the worm gearing 66, turns the shaft 61 and pinions 68 thereon that mesh with the racks 6|. The transmitting device I0 of the system is directly connected to a part of the drive connection between the motor 22 and the main p jector 0. The

a construction of the transmitting and receiving tween. As shown by Fig. 2 the selector switches I connect with one side of a source 50 of alternating current supply and the parts 41 and 48 connect with the other side of the source through the windings of the relays 5| and 52 which control the circuit of the motor. Interposed in the motor circuit is the reversing switch 53 whereby the motor may be operated in the proper direction depending upon whether the desired slide is on one side or on the other of the slide then in the projecting position. It is thought that the operation of this part of the apparatus will be so obvious from the above brief description and the drawings that a detailed description thereof will be unnecessary. I The focus of the projector remains fixed, being such that the projected images of the slides on surfaces in the focal plane will be exactly full size. Where, as in the present case, a high degree of precision in the projected image is required it devices and their respective connections with the projectors 20 and 51 are such that the projector 51 and mirror 58 are caused to have exactly the same movements as the main projector 20.

In Fig. 3 we have shown at H a. combined starting, stopping and reversing switch for'the motor 22, the motor and the transmitting and receivln devices being shown connected to beenergized from the source 50. We have also shown theinotor 22 provided with a common form of automotive brake comprising the drum I2. the spring applied brake shoe 13 and the retractin solenoid 14.

We have chosen the particular, embodiment described above as illustrative of our invention and it will be apparent that various modifications may be made .without departing from the spirit and scope of our invention which modifications we aim to cover b the appended claims.

What we claim as new and desire to secure by Letters Patent of the United Statesis:

1. In combination, means for supporting an article tobe inspected, means for projecting an image thereon comprising a projector having a slide picturing said article as it should appear when an operation thereon is finished, means indicating the position of the outer focal plane of and extending in a direction at right angles to the axis of projection at the focal distance from said projecting means, and means for simultaneously moving said projecting means and said his dicating means toward and from said article and for maintaining a fixed distance between said two means.

2. In combination, for supporting an article to be inspected, means for projectingan image thereon comprising a projector having a slide picturing said article as-it should appear when an operation thereon is finished, means for projecting a narrow light beam to indicat'ethe position of the focal plane of and extending in a direction at right angles to the axis of projection at the focal distancefrom said projecting means, and means for simultaneously moving said image projecting means and said light beam projecting means toward and from said article, said last means including means operable to maintain a fixed distance between the two projecting means.

3. In combination, a rotatable member for supporting a article-to be inspected, means for rotating d member to various angular positions, means for raising and lowering said member, a projector having a plurality of slides picturing said article as it should appear in various angular positions, means for bodily adjusting the position of said projector thereby to adjust the position of the focal plane with respect to said article, means indicating the position of said focal plane, and means operative to adjust the position of said indicating means and to maintain it at a fixed distance from said projector.

4. In combination, means for supporting an Y article to be inspected and laid out, a first projector adjustably positioned with respect to said supporting means for projecting on said article an imagedepicting the correct appearance of the article, a second projector spaced from said first projector and arranged to projects, sheet-like beam of light coincident with the focal plane of "said first projector, and means for maintaining fixed the spacing between said projectors.

5. In combination, a turntable for supporting a casting to be inspected and laid out, means for raising and lowering said turntable, means for adjusting the turntable laterally, a first projector,

having a slide carrier adapted to hold a plurality of slides, remote control means for shifting said carrier t bring any desired slide therein into projecting position, motor mechanism for adjust-. ing the position of said projector with respect to said casting, an adjustably mounted second projector for projecting a sheet-like beam of light to indicate the focal plane of said first projector, and interconnected electrical devices associated with said motor mechanism and said second projector for adjusting the position of the second projector in accordance with the adjustments of said first projector.

JOHN H. HOGAN. CLARENCE J. xn'rrrnn. manner a. JUDKINS. 'rnnonoan w. HALL.

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