Oct. 17, 1961 F. E.

LAYTON ETA 3,004,371

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INVENTORS:
FORREST E. | ?????
HARRY I. SOLE
Oct. 17, 1961 F. E. LAYTON ET AL 3,004,371
BENCH-TYPE LAPPING MACHINE
Filed April 8, 1958 3. Sheets-Sheet 3

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INVENTORS:
FOR REST E. LAYTON
HARRY I. SOLE
 3,004,37
United States Patent Office
*owcrogowaków: Awasakseats scaraxesearwa
Patented Oct. 17, 1961
2
3,004,371. the output shaft 9 of a reduction gear drive 20, the
BENCHTYPE LA.PNG MACHINE housing 2 of which may be formed as an integral part
Forrest E. Layon, North repok, ara Harry ä. Soe, Evans of the housing 22 of an electric drive motor 23. Said
Éon, ils, assignors to Cragae. Àºacking €ompany, Morton notor and reduction gearing may be of any well known
Grove, E., a corporation of Einois and readily available type and hence the details of con
Filed Apr. 8, 1958, Ser. No. 727, 196 struction thereof will not be described herein.
2 Claims. (C. 51-29)
Lap 10 is secured to the fianged end 16 of drive shaft
This invention relates to a bench-type flat lapping ET by a machine screw 24 preferably passing through a
machine. counter-Sunk opening disposed in the center of lap 10 and
The principal object of this invention is the provision O threaded into a corresponding opening 25 concentric with
of a small, inexpensive lapping machine for use primarily the axis of the flanged end 6 of shaft 17. Driving torque
as a tool in a machine shop or the like or for lapping is transmitted from shaft 17 to lap 10 by a drive pin 26
Small runs of articles. press-fitted into an appropriate opening in the flanged end
As a more specific object, this invention has within 26 of the shaft and extending upwardly beyond surface
its purview the provision of a bench-type lapping machine E5 into a recess 27 formed in the underside of lap 10.
which incorporates an inexpensive means for removing The drive from shaft 9 to shaft 7 is effected by a key
spent grit and lapping debris from the area immediately 23 interlocking the two shafts and held in place by a set
adjacent the effective lapping surface. Screw 29.
A specific object of this invention is the provision of Some of the spent grit and lapping debris falls into
a simple, adjustable holding means for articles on a lap, 20 recess i and is conducted therefrom through radially and
said holding means being sufficiently adaptable to hold in downwardly disposed passages 3 and 3 to the exterior
Oile arrangement a pair of cylindrical articles on the lap cylindrical surface 32 of lap 56, while the rest moves
with the end faces of the articles in contact with the lap radially outwardly on surface i2 or along grooves 13
Surface, and in another arrangement, to hold between directly to said cylindrical surface 32. The grit and debris
them a single larger cylindrical object with its end face 25 failing along cylindrical surface 34 is then collected in
similarly disposed. an annular container 33. having a cylindrical outer Wall
A further object of this invention is the provision of a 34, an inner cylindrical wall 35 and a connecting frusto
holding means for an article on a flat lap, said means conical wall 36. It is understood that walls 34 and 35
being capable of swinging adjustment in an arc over the need not be cylindrical but for ease of manufacture are
lap and also of adjustment in a vertical direction to ac 30 preferably made so. Thus, for example, container 33 may
commodate articles of various heights on the lap. be a sheet metal stamping and hence may be more readily
A feature of this invention is a novel support for the made if walls 34 and 35 are substantially cylindrical.
'drive means for an annular lap, said support also serving Outer cylindrical wall 34 has an inner diameter which
as a Support for an annular container for spent grit and is slightly greater than the diameter of the exterior cylin
lapping debris. 35 drical surface 32 of lap 50 to allow the grit and debris
These and other objects and features of this invention to pass therebetween, and extends upward around the
Will become apparent from the following detailed descrip lower regions of lap 69, particularly above the exit ends
tion when taken together with the accompanying drawings 38, 39 of the passages 30 and 32, respectively, so that
in which, . the grit and debris issuing from said exit ends will fall
F.G. 1 is a plan view of a lapping machine incorporat 40 into container 33. The upper edge 40 of outer wall 34 is
ing the features of this invention; rolled over to give stiffness to said edge and also to pro
FIG. 2 is a side elevational view, partly in section, vide a smoothly rounded entering and locating surface
of the machine of FIG. 1; for lap 50 when said lap is assembled with respect to
F.G. 3 is an end elevational view of the machine of shaft 7.
F.G. 1 with a portion of the end of the machine broken 45 To provide greater assurance that the contents of con
away to show the interior thereof; tainer 33 will not flow over inner wall 35 into housing 21
FIG. 4 is a fragmentary section taken in the direction of the gear reducer 20, wall 35 is likewise made to ex
of the arrows at line 4-4 in FIG. 1 showing a detail of tend upward beyond surface 5 into an annular groove
construction of the machine; -, 4 formed in said surface 15.
SO Container 33 is drained through a pipe 42, shown more
FIG. 5 is a plan view, on a reduced scale, of the
machine of FIG. 1 showing the article holding means clearly in FIGS. 1 and 3, threaded into a fitting 43 welded
adjusted for holding a large cylindrical object on the lap; to the lower region of outer cylindrical wall 34 over an
and opening 44 therein. Said pipe 42 is supported in Such
FIG. 6 is an elevational view of a detail of the machine 55 manner that the inner wall thereof slopes downward and
of FIG. 1. promotes natural drainage of the contents of the con
Referring now to the drawings, and particularly to tainer through the pipe to any suitable collecting means
FIGS. 1 and 2, for a detailed description of the invention, (not shown) provided by the operator. Movement of the
there is shown a flat, disc-shaped lap 10 having a recess contents of the container past opening 44 to promote
11 in the central region of its upper surface to provide flow therethrough is established by a paddle 45 (FEG. 2)
an annular lap surface 12 thereon. Said surface 12 may 60 preferably made of sheet metal and having a contour
have a series of radially disposed slots 13, or a single closely following the cross-sectional contour of container
spiral groove (not shown), milled or otherwise formed 33. Said paddle 45 has a horizontally disposed flange 46
in it for the purpose of conducting spent grit and lapping (FIG. 3) which abuts on the underside of lap 10 and
debris from the lap surface. Lap 10 has a substantial
provides a means for applying fasteners 47 therethrough
65 to the said underside of the lap. It may be appreciated
thickness to provide rigidity for the purpose of maintain that as the lap is rotated, paddle 45 will be rotated with
ing a given contour on surface 12. it and will sweep around container 34, thus moving any
Lap 10 may have flat undersurface 35 upon which the lapping compound or debris collected therein past open
lap is supported from the flanged end 16 of a drive shaft ing 44 while at the same time preventing a settling out of
17. The axis of shaft 17 is vertically disposed, and the O the compound.
lower region of the shaft has a relatively deep round re Container 33, as well as housing 21 of the reduction
cess 18 into which is inserted, with a relatively close fit, gearing 20, are supported by a plate 48 which, in turn,
 3,004,371
3 4.
is supported from the top plate 49 of the frame 50 of the other apex 79 of the triangular plate 73 is disposed a sec
lapping machine. Said plate 48 may be cut to have an ond roller 80 having a surface 81 which extends out
octagonal outer edge 51 (FIG. 1) and a circular inner wardly beyond the adjacent edges of plate 73. It is con
edge 52 (FIGS. 2 and 3), but it is understood that the templated that plate 73 will be so disposed relative to
contour of the outer and inner edges of plate 48 are not surface 12 that a ring 71 may be supported rotatably be
material to the operation of this invention and may be tween surfaces 76 and 80 of rollers 75 and 81, it being
varied to Suit special circumstances. The support for plate understood that the distance between said surfaces is less
48 is comprised of a plurality of vertically disposed weld than the diameter of the outer surface of ring 71 and
ments 53 (FIG. 4) preferably of rectangular outline and that the axes of rollers 75 and 81 are parallel to the
Welded at the top and bottom to the upper and lower O axis of ring 71.
plates 49 and 48, respectively. Said weldments 53 are The supporting means for plate 73 includes a threaded
disposed near the octagonal edge 51 of plate 48 and, of post 82, the lower end of which passes through an open
course, outside the container 33. ing 84 in top plate 49 and into the threaded opening 85
It may be observed from FIGS. 2 and 3 that upper of a boss 83 formed by welding or otherwise rigidly se
plate 49 has a circular opening 54 therein through which 5 curing a cylinder of metal to the underside of top plate
extends, in relatively close proximity thereto, the outer 49. Post 32 is prevented from turning relative to thread -
cylindrical wall 34 of container 33. It may be noted ed bushing 83, once its desired vertical position is estab
further that the rolled edge 40 of the wall 34 is disposed lished, by a lock nut 86 threaded over post 82 and clamped
above the upper surface of plate 49 and overlaps and against the upper surface of top plate 49. For conven
conceals the edge of the opening 54. 20 ience in turning post 82, the upper end 87 of the post
Housing 2 is provided with the usual attaching flange may be squared off to accommodate a Wrench or the
55 which abuts on the underside of plate 48 and is se like.
cured thereto by a series of bolts 56. Container 33 is se - Extending upwardly from the upper surface 88 of the
cured to the upper side of plate 48 through a plurality squared end 87 of post 82 is a threaded extension 89 of
of Z-shaped stamped tabs 57, the upper leg 58 of which 25 reduced diameter, said extension 89 being either integral
may be spot welded to the inner peripheral regions of the with post 82, or it may be a stud threaded into an appro
frusto-conical bottom wall 36 of the container and the priate opening in said post. Upper surface 88 is made
lower legs 59 of which are fastened to the upper surface perfectly flat and square with the axis of the post 82 the
of plate 4S by screws 60. It is contemplated that con latter in turn being parallel with the lap axis. Plate 73
tainer 33 will be supported at its inner edges by the tabs 30 is formed with an elongated slot 90 through which ex
57 and that its outer edge will rest upon the upper sur tension 89 protrudes so that plate 73 rests upon the flat
face of plate 48. surface 88. Said plate 73 is clamped to surface 88 by
Frame 50 is comprised, in addition to top plate 49, of a hand nut 91 threaded over extension 89 and bearing
a side skirt 6 to the upper edge of which plate 49 may against plate 73 to clamp the plate against said surface 88.
be welded or otherwise secured, said skirt being shaped 35 An alternate and convenient means is provided for turn
to form legs 62 in the corners thereof, the bottom of said
legs being covered by a plate 63 suitably welded to the
ing post 82 in bushing 83 without the aid of a Wrench
or special tool said means comprising (FIG. 6) a raised,
inner surfaces of the skirt corner and provided with a parallel sided extension 101 on upper surface 88 fitting
threaded opening 64 for the reception of a fastener G5 snugly into slot 90 in plate 73. Thus plate 73 may serve
by which a rubber foot 66 may be secured to said plate 40 as the wrench for turning post 82.
63. Appropriate openings 67, 68 and 69 are provided The rotatable support for ring 72 is identical in every
in the end and back regions of the skirt 6 for ventila respect to that for ring 71 and hence will not be described
tion purposes and for access to the drain pipe 42 as well in detail herein, it being sufficient to state that it is com
as to a plug 70 by which lubricant may be introduced prised of a post 92 to which may be clamped a plate 93
into housing 21 of the gear reducer 20. 45 having an arm 94 on the end of which is a roller 95, a
Considering now the operative surface 12 of the lap second roller 96 on plate 93 being spaced from roller
10, it is contemplated that articles may be lapped on said 95 a lesser distance than the outside diameter of ring 72
surface 12 either by being held thereon by an operator so that said ring is supported against movement with the
while the lap is rotating, or by being placed in suitable lap by said rollers 95 and 96. A hand nut 97 locks plate
holders provided for that purpose on the machine so that 93 on its post 92. It is understood that posts 82 and 92
the operator may be occupied elsewhere while the articles SO are interchangeable as well as plates 73 and 93 and hand
are being lapped. Furthermore, it is contemplated that nuts 9 and 97.
means may be provided for automatically maintaining It may be apparent that posts 82 and 92 may be ad
the lap flat while articles are being lapped thereon in the justed vertically to accommodate rings of different height
manner disclosed in E. J. Bullard Reissue Patent No. 59n lap surface 12 and the plates 73 and 93 may be ad
23,937 dated February 8, 1955. justed both angularly and translatively with respect to the
To accomplish the above ends, lap surface 12 may posts to give great freedom of choice as to the location of
have placed thereon one or more rings 71, 72 constructed an article on lap surface.12. Thus, work may be placed
of a material adapted to wear the surface 12 and have in rings 71 and 72 and the location of said rings with ref
a size large enough to cause the outer peripheral regions
101 (FIG. 2) to overhang the exterior cylindrical surface 60 erence to lap surface 12 so selected as to cause said Surface
to remain true to its original contour for a long period of
32 of lap 10, and also to overlap, or overhang, the time despite the fact that such surface may be continually
edges of the recess 11 while the inner surface 72A of the abraded by the articles being lapped. Alternatively, in
ring 71 is of either the same, or slightly smaller, size place of one or both rings 71, 72, a cylindrical object may
as the radial dimension of annular lap surface 2. Said be placed on lap surface 12 and made to bear against
rings have bottom surfaces of a contour complementary 65
rollers 75 and 80, or 95 and 96 directly, while the article
to the contour of the lap surface E2 which sweep over is being lapped.
lap surface E2 and continually dress the said lap surface, Occasionally, it may be desirable or necessary to lap
all as described in the aforementioned patent to Bullard. a cylindrical article which is considerably larger in dia
The means for holding ring 71 on lap surface 12 meter than rings 71 and 72. Such over-sized articles may
against revolution therewith is comprised of a triangular nevertheless be successfully lapped on the foregoing ma
plate 73 having a curved arm 74 extending from one of
the corners thereof and supporting at the end thereof a chine by arranging the plates 73 and 93 in the manner illus
freely rotatable roller 75, the diameter of which is such trated in FIG. 5. Thus, assuming that the over-sized
as to cause the outer surface 76 of the roller to extend article 98 is of approximately the size illustrated in FIG. 5
beyond the opposed edges of 77, 78 of the arm, nan 5 such that it would extend across central recess 11 if the
 3,004,871
5 6
outer edge thereof did not greatly overlap the outer edge locations shown in FIG. 1 being illustrative of the extreme
of the lap. For an object of such size a spacing between radially inner and outer positions likely to be encountered.
the rollers 75 and 80 might not be sufficient to retain the It may be apparent that the foregoing machine, when de
article on the lap under certain conditions of operation. signed for use with a lap plate 10 of small diameter, e.g.,
It is therefore desirable to make use of both plates 73 and ten inches, may be inexpensively constructed and yet will
93 and use roller 75 of plate 73 and roller 95 of plate accommodate a large range of sizes of articles as well as
93 to provide a roller support for the article 98 wherein provide automatic conditioning of the lap so that the
the rollers are spaced apart a sufficient distance to ensure machine may be used continuously for small production
the retention of the article on the lap 12 at all times. TS,
Roller 95 is made available for this purpose by rotating O It is understood that the foregoing description is merely
plate 93 to such an extent that what amounts to the back illustrative of a preferred embodiment of the invention and
of plate 93 is presented to the article 98 and roller 96 is that the scope of the invention therefore is not to be
unused. Similarly, plate 73 is rotated to such an extent limited thereto, but is to be determined by the appended
that roller 75 only contacts article 98, roller 80 being dis claims.
posed in proximity to, but not necessarily in contact with 5 We claim:
the article 98. 1. A lapping machine comprising a rotatable lap, a
Obviously, when an article such as the one shown in pivoted support for articles to be lapped on said lap, said
FIG. 5 is being lapped, there is no room for a conditioning Support comprising a fixed frame having a threaded open
ring such as 71 or 72 on the lap at the same time, and ing, a post having a threaded region engaging said threaded
hence the conditioning of the lap under these circum 20 opening and extending above the frame in proximity to the
stances must be performed when the article is removed. lap, said post having a flat-sided region adjacent the
In addition to the arrangement of plates 73 and 93 threaded region thereon, a plate extending in part over the
as shown in FIG. 5, it is obvious that said plates may be lap end having a slot therein, said flat-sided end region
reversed in the sense that they are inverted, the inverted extending into and engaging the side of the slot and locked
position being available for relatively high articles to make 25 against rotation relatively thereto by such engagement with
certain that ample clearance would still remain for the the side of the slot but free to slide transversely of the post
arms of the plates above the lap surface 12. to vary the amount by which the plate extends over the
The machine may be provided with an off-on switch 99 lap, means on the plate for engaging an article to be
and a timer switch 100, both of which may be disposed apped on the lap, means for locking the plate to the post
in a conveniently accessible location of the machine, pref 30 against such transverse sliding thereon, and means for
erably on the skirt 61 adjacent the motor 23 which it is locking the post to the frame against relative rotation there
desired to control. Both switch 99 and timer switch 100 with, said plate functioning as a wrench to turn the post
may be of known and readily available construction and when said post is not locked to the frame.
hence the details thereof will not be described herein. 2. A lapping machine as described in claim 1, said post
Suffice it to say, that with switch 99 in its “on” position, 35 having a shoulder between the flat-sided region and the
timer switch 100 may be set for any desired duration of threaded region against which the plate bears, and said
operation of motor 23 within the limits of the timer means for locking the plate to the post comprising a hand
Switch, and upon the lapse of the time set, the motor will nut threaded on the end of the post adjacent the plate
cease operating so that it is unnecessary for an operator and adapted to clamp the plate against the shoulder.
to stand by the machine once he has placed an article to 40
be lapped on plate 12 and set the machine in operation. References Cited in the file of this patent
The general operation of the above-described lapping UNITED STATES PATENTS
machine is the same as that described in the aforesaid 1,569,194 Long------------------- Jan. 12, 1926
Bullard patent. Conditioning rings 71 and 72 may be 2,274,332 Jarrett ----------------- Feb. 24, 1942
shifted axially to those positions on the lap surface 12 at 45 2,627,144 Roshong ---------------- Feb. 3, 1953
which the desired lap surface contour is maintained. The 2,653,422 Roshong --------------- Sept. 29, 1953
rings may be located the same distance from the center 2,782.57.1 Hanson ---------------- Feb. 26, 1957
of lap 10, or they may be located at different distances, the