US2695726A - Stamped-metal access plate for gearboxes - Google Patents

Description

Nov. 30, 1954 H. B. CHATFIELD 2,695,726

STAMPED-METAL ACCESS PLATE FOR yGEARBOXES Filed Jan. 8. 1951 2 sheets-shet i INVEN TOR. HENRY B-C//ATF/ELD BY KM.

A TTOIP/VEYS United States Patent C) STAMPED-METAL ACCESS PLATE FOR- GEARBOXES Hem-.y B. Chatlield, Kinsman Ohio,

Application lJanuary! 8 1951, Serial` No. 204,990

101Cl'aims., (Cl. 22m-415)v 'Dhisinvention relates to a process and the product; of;

at process for. manufacturing.stamped-metal` access plates for gear boxes, transmission. casings, pumps, reactors,

pressure vessels., and similar movable and immovable units. making; use ofi a. housing of somel suitable, kind` in which at tight seal is. desired between.. the housmg; and

the access plate. Heretofore, access. platesA for these. purposes. have ordinarily` been made in.4 theA form of` castings, of malleable fastening elements, the access. plate is located andheld` intplaceton. the housing. Such, accesszplartes .are .relatively expensive tov manufacture. Up` to they presentl time, savings; ofimpressive proportions in 'materials `and costs have;

been sacriii'cedl that would have been enjoyed if satisfactory: accessfplates` could: have been made of metal starnpings;` however, it has not heretofore been known how to make. stamped-metal access; plates that would' give.,` the;` desired. sealing action between. the'v seating surfacesf, on the access plate and.v theycoopera-ting:surfaces on thehousing.

Previous attempts. to` manufacture stamped-metal access plates, of which there have been. many, havebeen aimed at; obtaining, aA seal by= maintaining the. sealing surface atwithin: one or two thonsandthslof. an. inch: this; 'hask resulted in` excessive scrap, excessive die maintenance, or the,` additioni of a. surface4 grinding operation.

It. is. an. object: of the-present: invention to provide a stampedemetal, access plate, and' in. some aspects ofthe inventionA anaccessplate that isfbuilt up of a. plurality of metal; stampings thatmay. beA used inA lieu` of the castmetaltaccess plates. ofthe kindsheretofore generally. employed, It is a further. objectl of the invention to.provide a, stamped-metal.l access.` plate that will giveI the` desired sealing; action, this even when substantial pressuresmust b ej resisted. It is al further object of, the invention to provide; a stamped-metal access plate` that'. permits.` a` substantially constant sealing pressure to be maintained at alltpoints along` the sealing surface. It isfstill a further objectof theA invention `toreduce` .the-cost of accesslplates to ,a minor. fraction of thegcosnof; cast-metal; access` plates of` thikindsgheretofore used. Gtherobjects andaadlvan- .tagesl ofY theV invention willb'e apparent. from:` theidescription which.follows as well as fromv the accompanying drawings.

In thefdrawings,Figure;1` isa topplan of' the preferred tyBe-of; accessgplateshowing the; same after the channellikestructure encompassingthefbody portionof the access-plate'hasxbeenstruck; from the; blank. Figure@ is a sectionondine Z-ZrofpFigure 1. looking in.thedirection ofthe-arrows. Figure 3 is a topplanof .the4 accessplate at` aJater, stage in theprocess ofr manufacture. Figure4 isa, section similar to that of Figure 2f on line 4-4.of Figure, FigureyS is,r atopplanaof the access plate at a,st.ll.1aterstage1inthe process'of manufacture. Figure 6 By;I contrast-withFiguresl to 9, all. of; which arexonia. reduced, scale, Figures l0 to 141- aref of ullsvsizel.A Figure` 1.01is a View` partly in` verticab central section andtipartlyv4 inl side elevation of the preferred` type: of access: pla-tez applied to the top of a.A gear box. Figure.: lil; is; a view' partly in vertical central section. and partly.1 in. side. elevation of a modified. form of an access;plate,.likewise applied toa gear. box; Figure 12 is a detailzof themodiiied` form of :access plate seen.` in` endI elevation as if from. the. left: hand endof Figure. ll. Figure. lf3. is` a similar view` of. the channel forming. partof the modified form:- of access plate. Figure 14 is a transverse vertical section. with parts in elevation through an access plate ofy theoil` pan type that isfor-medin a manner. otherwise analogous to that ofthe preferred type; of accesspla'te of. Figures l to. 10, inclusive.

The access` plate shown in'iinished formtin Figures 6, 8 and 10` is shown alsoz in applicants copending application Serial No. 204,989, led.l'anuary'8,.195l,.for AccessPlate.

In the form in which it is shown; in Figures l and. 2, the preferredv type of access plate, generally designated.' l in Figures l to 9, inclusive, isin an early stage inthe process of its manufacture. At this stage,A a flat sheetmetal. blank of appropriate shape` has been given pre.- liminary form by subjecting it to the action of two cooperating dies, male and female. It hasa flat bodyportion 2` that as. shown. is polygonal but maybe of any other desired shape; e. g., rectangular, square,.circular, etc. Body portion 2x is surrounded by an. encompassingV peripheralv channel 3" that has been struck up from the blank by the action` ofv the dies. As appears from Fig-t ure 2, peripheralchannel'isgenerally U-shaped in crosssection, being characterized by an inner wall 4 risingv abruptly from bodylportion 2, an intermediate portion' 5 extending outwardly ina manner permitting it to serve asthe bottom portion or base of channel 3, andianouter wall `6. parallelinginner wall 4'; Depending from. outer wally 6: -below the plane ofi body portion 2 are flash-likeears 7 which are removed by. a` suitable operation, such as .pinch-trimming.

After the. incompletely formed` access plate has been trimmed tov eliminate ears 7, it isworked` between a second: pair of cooperating dies.torestrike peripheralchannel 3 to the desired linished size. In this same operation,. locating bosses 9` are formed in inner wall 4` of channel. 3, such. bosses projecting: toward the interior ofi .theaccess plate in themanner. most clearly shown in Figure 3. Inthe same operation, or, if desired; by. a separate operation, those: portions of theaccess plateatwhic'hinner wall 4' of channel 3 impinges onV body` portion 2 are det`o1med`,.as` by pressure applied from above by a die, to. form. a; smoothly-faired convex or downwardly bowed portion 10 in the stretches between4 adjacent bosses 9.

Suchrconvex portions lllusually have a radius ofcurva- `ture so great: that: the convexity is almost imperceptible to the eye; nevertheless, each of them as Viewedl inside elevation. presents the general configuration of a shallowr catenary or like curve. Convex portions 1l), which appcarin exaggerated fashion.` in Figure 4 and subsequent figures, willordinarily have a maximum heightl of: more than about 0.001 but less than about 0.090 inch, measured from, the proximate plane. of body. portion 2; Theprecise value, which is. a function-of the pressure to be retained,` the distances betweenfastening elements and the nature of the fastening elements themselves, should be lessttlian-that amount which would give `risexto permanent flattening as a. result of the imposition o'f forces exceeding the` elasticlimit of the, metal upon application ofthe fastening elements to the access plate;

The result of forming convex portions `10 is to introduce into what may be regardedas the edge of inner wall 4 of` peripheral channel. 3 a plurality of widely spaced longitudinally extending undulations, such` undulations being of maximum height, measured from the proximate plane of body portion 2, approximately mid-way between each two adjacent'- bosses` 9. Although, as indicated above,` preferred practice involves` forming convex porticnsflO. in the same .operationin which peripheral channell` 3,: is' 11e-struckn and bosses 9. are. introduced intoV itsl inner wall, the; undulations may, ifl desired, bedeveloped in. anyr other desired; way or` at some` other. stage f in the;

3 process of manufacture of access plate 1. Usually, however, it will be desirable to form the undulations before undertaking the operations described hereinafter.

Convex portions 10 having been formed in some suitable way, the next following operation may conveniently be the opera-tion of forming outwardly of bosses 9 the at portions 11 (iiats) which appear in Figure 5 and subsequent igures. This likewise is done by means of cooperating dies. Simultaneously therewith, it is convenient to coin the opposite face of access plate 1. Such coining operation is for the purpose of providing smooth surfaces on those portions of access plate 1 underlylng inner wall 4 of channel 3; i. e., those portions of access plate 1 at which peripheral channel 3 impinges on body portion 2.

lIn the course of the coining operation, a groove 13 (Figure 6) is produced on the top face of the access plate and smooth seating surfaces 14 (Figure 9) are developed on the bottom face of the access plate. The coining operation should not be carried so far as to destroy the catenary-like curves of convex portions 1t); however, a small part of the original convexity is of course eliminated by the coining step. The amount of material removed is important in the sense that enough convexity must'remain so that the convexity, measured from the proximate plane of body portion 2, exceeds the aggregate of the manufacturing tolerances on the opposed portions of the housing, access plate, and gasket.

After introducing flats 1'1 and performing the coining operation giving rise to grooves 13 and seating surfaces 14 on the obverse and reverse sides of access plate 1, respectively, means for attaching the access plate to the housing are incorporated in it. While various ways of attaching the access plate to the housing may be employed, preferred practice involves the introduction of openings of suitable size and shape, such, for example, as circular holes 12, one at the geometrical center of each of flats 11. This may be done by piercing, punching or in any other suitable way, giving the finished access plate, viewed from above, the appearance indicated in Figure 6. Viewed from below, the finished access plate has the appearance presented by the bottom plan constituting Figure 9 of the drawings. `In a typical case, the access plate illustrated on a somewhat reduced scale in Figures l to 9 has an overall length, measured from side to side in Figure 6, of approximately inches and an overall width of approxim-ately 41/2 inches. Channel 3 may have an overall height of about inch, measuring from the bottom of body portion 2 to the top of channel 3. The width lof channel 3 at its edges; that is to say, the width of the opening as measured in the plane of body portion 2, may be of the order of about 1A inch. Hole 12 in iiats 11 adjacent bosses 9 may in such case be spaced about 21/2 inches from each other. Obviously, all of these dimensions and the ratios between them may be varied within very wide limits.

The preferred type of access plate is of sheet steel of relatively heavy gauge; e. g., l3-gauge, .and of one of the many compositi-ons lending themselves to st-amping and use in access plates of the kind described, although it may, if desired, be formed of suitable non-ferrous metal.

Figure l0 shows access plate 1 applied to a gear box 15 having an opening 16 through which access may be had to the interior of the gear box. Extending upward from gear box 15 are studs 17, the same being suitably located around the periphery of opening 16. Onto studs 17 are threaded the nuts 18, the latter seating on flats 1'1 adjacent locating bosses 9. Between the access plate and the gear box is a gasket 19, which may be made of oil-impregnated kraft paper about .010 inch in thickness. ln seating on gear box 15, the convex portions of the access plate giving the undulatory elect to lthe seating surface come first into contact with the gasket 19 appr-oximately mid-way of the stretches between studs 17; thereafter, as nuts 18 are screwed home, the other portions of the seating surface of the access plate, including those in which locating bosses 9 are formed, come progressively into contact with the gasket, compressing it against gear box 15.

The modified form of access plate shown in Figures ll to 13 is made up of two metal stampings, one of them a substantially at sheet 21, provided, if desired, with one or more reinforcing ribs 22, which sheet serves as the body portion of the access plate. Impinging upon body portion 21 is the separately formed peripheral channel 23, the same being generally U-shaped in cross-section and consisting of an inner wall 24, an outer wall 25, andv a substantially iiat connecting portion 26. Channel 23 is formed with spaced indentations 27 in its inner and outer walls, such indentations locating the means for positioning and attaching the fastening elements (studs 17 and nuts 18) that hold the access plate to gear box 15. Such means include registering openings in gasket 19, body portion 21 and connecting portion 26 between inner wall 24 and outer wall 25.

The edge of inner wall 24, and, if desired, also the edge of outer wall 25, is bowed between adjacent openings in a manner analogous to the bowing provided by convex portions 10 in the access plate of Figures 1 to 10, inclusive. Although shown in greatly exaggerated fashion, the bowing of the edge of inner wall 24 appears at 24a in Figure 13, which represents a channel in which the edge of the inner wall is bowed and the edge of the outer wall is not bowed. This bowing of the edge of the inner wall of the encompassing structure is communicated to body portion 21. When the built-up access plate of Figure 1l is applied to gear box '15, sealing action is obtained -both where the bowed portions overlie the edges of access opening 16 and where nuts 18 on studs 17 urge the parts together.

For 4the purpose of holding channel 23 in place on body portion 21, the latter is provided at each end with a projection 28 which carries an inwardly extending tang. 29. Tangs 29 are preferably integral with projections 28 and the latter are preferably integral with 'body portion 21. When the parts are assembled to form the access plate, each tang 29 is forced into a recess 30 in outer wall 2S of peripheral channel 23, thus providing a mechanical interlocking of the parts as indicated, for example, in Figure l2. While this construction maybe used not only at the ends but also along the sides of the access plate, two are suicient in an ordinary case to hold peripheral channel 23 firmly in place on body portion 21.

If desired, in each of these embodiments of the invention, the outer wall of the peripheral channelmay be interrupted or even largely eliminated, leaving an encompassing structure -that may nevertheless be described as channel-like in the sense that when the access plate is applied to a gear box or the like, the resulting open-sided hollow has the characteristics of a laterally extending or outwardly facing channel.

In each of the forms of the invention heretofore described, the encompassing structure is of a height greater than the maximum height of the intervening body portion. It is of course possible to have lthe body portion raised above or depressed below the encompassing structure. This is illustrated in Figure 14, which shows an integrally formed access plate of the oil-pan type, such access plate 'being applied to a housing 32 having an opening 33 from which it is separated from a gasket 34 and to which it is aixed by bolts 35. The body portion 36 of the access plate is offset from the seating surfaces at the edge of Ithe inner wall of the channel. Between side wall 37 and the channel is a hollow 38 into which the tool used in the coining operation enters when the seating surfaces are formed. l

Thus the invention provides a stamped-metal laccess plate in which sealing contact with the gasket or, lacking a gasket, with the housing itself is established tirst ap proximately midway of the stretches between adjoining fastening elements. As the fastening elements are made tight, those portions of the access plate which do not make such -contact initially; e. g., the portions of the access plate adjacent the fastening elements, are urged progressively into position, this lbeing possible because of the inherent resilience of the metal itself. A substantially constant sealing pressure thus may be achieved and maintained along lthe entire sealing surface. Ilf desired, however, the overall amplitude of the undulations as measured from the body portion of the access plate can be increased to a point where the pressure, disregarding manufacture tolerances, is greater mid-way `between fastening elements than elsewhere, this being the precise opposite of the condition that obtains in ordinary access plates of the kinds heretofore used.

It is apparent that numerous modiications and departures may be introduced into the stamped-metal access plates described in the foregoing specification. The preferred construction is an integral construction of the kind illustrated in Figures 1 to 10 and14. 'Howeven as illustrated in Figures 11 to 13, a stamped access plate may, if desired, be formed of a plurality of separate` sheet metal stampings. Elaborated forms of the invention made up of several such sheet metal stampings may readily be devised. As a general rule, they also will be characterized by a convexity or bowing providing a series of spaced undulations where the encompassing structure impinges upon or joins the body portion of the access plate.

It is intended that the patent shall cover, by surnmarization in the appended claims, whatever features of patentable novelty reside in the invention.

What is claimed is:

1. A stamped-metal access plate for a gear box or the like comprising a sheet metal stamping having a body portion; a seating portion on one side of the stamping near the periphery of the body portion, said seating portion being characterized by the presence therein of a succession of longitudinally extending undulations each of which is smoothly faired into the preceding and following undulations; and, on the opposite side of the stamping, a channel characterized by an inverted U- shaped cross-section having its bottom portion raised above the seating portion and in it integrally formed means adapted to receive the elements used in fastening the access plate in position, said integrally formed means and said seating portion being spaced from each other with the former offset from the latter in that dixection which leads away from the interior of the gear ox. t

2. An access plate as in claim 1 in which the channel is formed separately from the rest of the access plate.

3. A stamped-metal access plate for a gear box or the like comprising a sheet metal stamping having a body portion; a seating portion on one side of the stamping near the periphery of the body portion, said seating portion being characterized by the presence therein of a succession of longitudinally extending undulations each of which is smoothly faired into the preceding and following undulations; and, on the opposite side of the stamping, a channel characterized by an inverted U- shaped cross-section, one wall of which impinges upon the body portion of the access plate, the bottom portion of said channel being oifset from the general plane of said seating portion in that direction which leads away L,

from the interior of the gear box and having in it integrally formed means accommodating the elements used in fastening the access plate to the gear box.

4. A stamped-metal access plate for a gear box or the like comprising a sheet metal stamping having a body portion; a seating portion on one side of the stamping near the periphery of the body portion, said seating portion being characterized by the presence therein of a succession of longitudinally extending undulations each of which is smoothly faired into the preceding and foli lowing undulations; and, on the opposite side of the stamping, a channel characterized by an inverted U- shaped cross-section, which channel impinges upon the body portion of the access plate along the edge portion of its outer wall, the bottom portion of said channel being olfset from the general plane of said seating portion in that direction which leads away from the interior of the gear box and having in it integrally formed means accommodating the elements used in fastening the access plate to the gear box.

5. A stamped-metal access plate for a gear box or the like comprising a sheet metal stamping having a body portion; a seating portion on one side of the stamping near the periphery of the body portion, said seating portion being characterized by the presence therein of a succession of longitudinally extending undulations each of which is smoothly faired into the preceding and following undulations; and, on the opposite side of the stamping, a channel characterized by an inverted U-shaped crosssection which channel impinges upon the body portion of the access plate both along the edge portion of its inner wall and along the edge portion of its outer wall, the bottom portion of said channel being offset from the general plane of said seating portion in that direction which leads away from the interior of the gear box and having in it integrally formed means accommodating the elements used in fastening the access plate to the gear box.

6. An access plate as in claim 5 in which the body portion and the channel are held together in the desired relation to each other by means of extensions on one which project into recesses in the other.

7. An access plate as in claim 6 in which the channel is provided with recesses in which are received reversely bent tangs formed integrally with the body portion.

8. A stamped-metal access plate for a gear box or the like comprising a sheet metal stamping having a body portion; an undulatory seating portion on one side of the stamping near the periphery of the body portion; and, on the opposite side of the stamping, a channel having an inverted U-shaped cross-section the bottom of which channel is offset from the general plane of said seating portion in that direction which leads away from the interior of the gear box, said channel impinging upon the body portion of the access plate along the edge portion of the inner wall of the channel and having outwardly of said inner wall a series of openings for receiving the IeJlements used in fastening the access plate to the gear 9. A stamped-metal access plate for a gear box or the like comprising a sheet metal stamping having a body portion; an undulatory seating portion on one side of the stamping near the periphery of the body portion; and, on the opposite side of the stamping, a channel having an inverted U-shaped cross-section the bottom` of which channel is offset from the general plane of said seating portion in that direction which leads away from the interior of the gear box, said channel impinging upon the body portion of the access plate along the edge portion of the outer wall of the channel and having inwardly of said outer wall a series of openings for receiving the elements used in fastening the access plate to the gear box.

10. A stamped-metal access plate for a gear box or the like comprising a sheet metal stamping having a body portion; an undulatory seating portion on one side of the stamping near the periphery of the body portion; and, on the opposite side of the stamping, a channel having an inverted U-shaped cross-section the bottom of which channel is offset from the general plane of said seating portion in that direction which. leads away from the interior of the gear box, said channel impinging upon the body portion of the access plate both along the edge portion of the inner wall and along the edge portion of the outer wall of the channel and having between said inner wall and said outer wall a series of openings for receiving the elements used in fastening the access plate to the gear box.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,857,443 Draper May 10, 1932 1,890,936 Douglass Dec. 13, 1932 1,961,121 Knapp May 29, 1934 2,272,178 McDowell et al. Feb. 10, 1942

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