CA1176851A - Apparatus and method for surface finishing of a workpiece - Google Patents
Apparatus and method for surface finishing of a workpieceInfo
- Publication number
- CA1176851A CA1176851A CA000385058A CA385058A CA1176851A CA 1176851 A CA1176851 A CA 1176851A CA 000385058 A CA000385058 A CA 000385058A CA 385058 A CA385058 A CA 385058A CA 1176851 A CA1176851 A CA 1176851A
- Authority
- CA
- Canada
- Prior art keywords
- finishing
- mounting member
- housing
- rotation
- workpiece
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B5/00—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B41/00—Component parts such as frames, beds, carriages, headstocks
- B24B41/04—Headstocks; Working-spindles; Features relating thereto
- B24B41/047—Grinding heads for working on plane surfaces
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
- Polishing Bodies And Polishing Tools (AREA)
Abstract
A B S T R A C T
Apparatus for finishing a workpiece comprising a resilient abrasive finishing element arranged for motion relative to a workpiece surface and in pressure engagement therewith. Methods of finishing a workpiece employing this apparatus are also disclosed. Both grinding and high surface quality polishing may thus be provided using the same machine tool,such as a lathe or milling machine, and appropriate finishing elements.
Apparatus for finishing a workpiece comprising a resilient abrasive finishing element arranged for motion relative to a workpiece surface and in pressure engagement therewith. Methods of finishing a workpiece employing this apparatus are also disclosed. Both grinding and high surface quality polishing may thus be provided using the same machine tool,such as a lathe or milling machine, and appropriate finishing elements.
Description
~7~85~
The present invention relates to surface finishing apparatus which provides grinding and polishing functions.
Conventional techniques for precision machining of metal surfaces require that a workpiece be subjected to a conventional maching operation in a first machine and then be transferred to a second machine for a precision grinding and polishing operation. The required use of at least two processing machines involving the transfer of the workpiece from one to the other adds significantly to the time and cost involved in precision surface finishing and limits the quality which can be achieved. It is therefore desired to provide apparatus which is capable of producing a precision finished surface while requiring the use of only a single machine tool having replaceable finishing elements.
According to one aspect of the present invention there is provided an apparatus for effecting high tolerance finishing of a workpiece surface comprising:
a mounting member including attachment means suitable for attachment to rotary drive apparatus for ~' rotation of the mounting member about a first axis;
at least one resilient abrasive finishing element rotatably mounted on said mounting member for motion relative to said workpiece surface in a plane perpendicular to said first axis;
bearing means supporting said at least one finishing element on said mounting member for free rotation of said at least one finishing element relative to said mounting member; and means for collecting particulate matter generated during a finishing operation from wear of said finishing element mounted on said mounting member;
said at least one resilent abrasive finishing element comprising an annular body of uniformly intermixed resilient and abrasive substances.
; The invention will be more fully understood and appreciated from the following detailed description taken in conjunction with the drawing in which:
The present invention relates to surface finishing apparatus which provides grinding and polishing functions.
Conventional techniques for precision machining of metal surfaces require that a workpiece be subjected to a conventional maching operation in a first machine and then be transferred to a second machine for a precision grinding and polishing operation. The required use of at least two processing machines involving the transfer of the workpiece from one to the other adds significantly to the time and cost involved in precision surface finishing and limits the quality which can be achieved. It is therefore desired to provide apparatus which is capable of producing a precision finished surface while requiring the use of only a single machine tool having replaceable finishing elements.
According to one aspect of the present invention there is provided an apparatus for effecting high tolerance finishing of a workpiece surface comprising:
a mounting member including attachment means suitable for attachment to rotary drive apparatus for ~' rotation of the mounting member about a first axis;
at least one resilient abrasive finishing element rotatably mounted on said mounting member for motion relative to said workpiece surface in a plane perpendicular to said first axis;
bearing means supporting said at least one finishing element on said mounting member for free rotation of said at least one finishing element relative to said mounting member; and means for collecting particulate matter generated during a finishing operation from wear of said finishing element mounted on said mounting member;
said at least one resilent abrasive finishing element comprising an annular body of uniformly intermixed resilient and abrasive substances.
; The invention will be more fully understood and appreciated from the following detailed description taken in conjunction with the drawing in which:
- 2 ~
,. ~
768~1 Fig. 1 is a pictorial illustration of finishing apparatus associated with a workpiece and mounted onto a rotary milling machine of conventional construction;
- 2a -.,.~-~
;, !
1~7685~ I
Fig. 2 is a side view illustration of a finishing device constructed and operative in accordance with an embodiment of the invention;
F;g. 3 is a bottom view of the finishing device of Fig. 2;
Figs. 4A is a bottom view illustration of an alternative embodiment of a finishing device;
Fig. 4B is a schematic illustration of a further alternative embodiment of a finishing device;
Fig. 5 is a detailed illustration of a portion of a finishing device;
Fig. 6 is a partially cut away illustration of a finishing device;
Figs. 7, 8 and 9 each illustrate an embodiment of a finishing element;
Fig. lOA is a sectional side view illustration of a finishing device useful with a lathe or other turning machine;
Fig. lOB is a plan view of the device of Fig. lOA
taken in a direction indicated by an arrow B.
Fig. 11 is a side view of a fin;sh;ng tool for the interior surface of a workpiece, and Figs. 12A and 12B illustrate two alternative mounting orien~ations for an adjustably positionable finishing tool constructed and operative in accordance with an embodiment of the present invention.
The present in~ention provides finishing apparatus which may be em?loyed selectably for grinding~and polishing by suitable selection of the characteristics of the resi~ient abrasive finishing element. When used for polishing or grinding, sufficient pressure is provided such that the finishing element is compressed by approximately 30 - 300 microns thereby producing an area rather than line contact between the finishing element and the workpiece surface. Such a polishing technique provides a reduction of approximately 0.0005 mm and provides an extremely high quality surface finish of the order of between 16 and 2 microinch r.m.s., and preferably up to 4 - 2 microinch r.m.s.
,t76~
Such a grinding technique provides a reduction of approximately 5 - 50 microns.
It is appreciated that the finishing element in one embodiment of the invention undergoes a complex motion with respect to the workpiece which greatly adds to the quality of the surface finish. This complex ~otion comprises the rotation of the housing or base onto which the finishing element is mounted, the rotation of each finishing element about its own axis and the motion of the workpiece on a moveable table relative to the polishing element.
According to a preferred embodiment of the invention, the finishing technique includes rotation of the base or housing in opposite directions which may correspond to opposite directions of the workpiece movement on the moving table.
Reference is now made to Fig. 1 which illustrates finishing apparatus constructed in accordance with an embodiment of the present invention in operative association with a conventional milling machine for rotational engagement under pressure with a workpiece. The finishing apparatus is indicated generally by reference numeral 1 and comprises a body portion 3 and a shank portion 5 ~hich is insertable into the chuck of the milling machine 7 for rotation selectably in opposite directions about the spindle axis I - I of the milling machine, the body portion 3 and shank portion 5 constitute a mounting member with the shank portion 5 providing a means for attachment to the milling machine 7. The workpiece, 64, is preferably mounted on a movable table 65 associated with the milling machine.
Normally the finishing apparatus is rotated initially in a first direction while the movable table moves in a first longitudinal direction. Thereafter, as the table returns in an opposite direction, the rotation of the finishing apparatus may be in an opposite direction. This two direction capability provides evenly, randomly directly finishing marks.
The pressure engagement of the finishing apparatus with the workpiece surface is illustrated in ~ig. 1 by the extent 67 to which the finishing element indicated by reference numeral 68 is compressed when it engaged the workpiece surface. As noted above, this compression is approximately 30 - 300 microns. Preferably the pressure is exerted perpendicular to the workpiece surface.
Reference is now made to Figs. 2 and 3 and which illustrate the finishing apparatus of the present invention in greater detail. The apparatus comprises a housing base 71 which is fixedly attached to a shank 73 and supports a housing top portion 74 and bottom portion 76. Disposed !' mainly within the housing are a pair of finishing elements 75, typically in the form of annular disks. Elements 75 are mounted rigidly onto respective axles 77 which in turn are bearing mounted within the housing for relatively free rotation with respect thereto. The axes of rotation of both finishing elements 75 are identical and intersect with the axis of rotation of the housing indicated by reference numeral 79, as seen in Fig. 3.
It is a particular feature of the preferred embodiment of the present invention that housing top and bottom portions 74 and 76 together define means for collecting particulate matter which is produced as the result of the wearing down of the resilient finishing elements.
; As seen in Fig. 3, the finishing elements 75 are disposed mainly above the bottom surface of bottom housing portion 76 and only a portion thereof extends outside of the housing, through openings 81 formed in the bottom surface.
Openings 81 are constructed to be of as small an area as possible and therefore have a width only slightly greater than that of the finishing elements, sufficient to prevent interference with the free rotation thereof. The length of the openings is less than the diameter of the finishing elements. Thus particulate matter generated in a :
-- 5 ~
~7hr~
~ 3~3 finishing operation from wear of the finlshing element is gathered into the interior of the housing bottom portion 76 so as not to interfere with the finishing and not to provide uneven results and cause damage to the apparatus.
According to a preferred embodiment of the invention, illustrated schematically in Fig. 4A, the axes of rotation of the finish;ng elen~ents 75 are offset from each other and do not Is intersect axis 79. This non-intersection feature provides an additional vector moment of motion between the finishing element and the workpiece surface when housing base 71 is driven in rotary pressurized motion relative to the workpiece surface.
Fig. 4B illustrates finishing apparatus constructed and operative in accordance with a variation of the embodiment of Fig. 4A. Here finishing elements 80 and 82 are not mounted for independent free rotation relative to the housing 84, as in Fig. 4A but rather are interconnected by a transmission 86, typically comprising an odd or even number of gears. An even i~;
number of gears comprising gears 88, 90, 92 and 94, for example, is preferred since it provides rotation of elements 80 and 82 in respective opposite directions for enhanced finishing action.
It is noted that finishing elements 80 and 82 are offset by different i amounts from the rotation axis 96 of the housing, thus producing different speeds of rotation in the finishing elements, were the elements not connected by a fixed transmission. It is appreciated that the transmission may be constructed such that a non-unitary fixed ratio of speeds is maintained between the two finishing , elements. The two finishing elements may be constructed to be of different widths and to have differing abrasive characteristics. ~
Fig. 5 illustrates a preferred construction of a ~, portion of the bottom housing portion 76 wherein a recess 85 ;s ' .
, -6- ;~
.~
k defined at the inner periphery of the portion 76 for collection ' of particulate matter along the outermost portions of the interior of the housing under the influence of centrifugal forces produced by the high speed rotation of the housing during operation. Portions 87 of the housing bottom surface adjacent the finishing elements are bent upwardly to define a barrier for preventing, insofar as possible, particulate matter from escaping from the housing. The bottom portion 76 is constructed to be removable for easy cleaning.
.
A further development of the apparatus of Fig. 5 is illustrated in Fig. 6 and comprises a housing wherein the bottom portion 53 thereof is selectably positionable relative to finishing elements 75 in order to compensate for wear therein, and the resulting significant decrease in their diameter. Bottom portion 53 is spring mounted onto the housing base 71 by means of a pair of bent leaf springs 55 and is secured to the housing base by means of a screw fastener 57. The extent to which the screw fastener 57 is inserted into a corresponding socket 59 formed in the housing base 71 determines the relative disposition of the bottom surface of the bottom portion 53.
Figs. 7, 8 and 9 illustrate different embodiments of finishing elements constructed and operative in-accordance with an embodiment of the present invention. The element of Fig. 7 is of generally annular configuration having a truncated conical cross section of increasing width with decreasing radius and is formed of a resilient material, typically rubber based, having abrasive material, typically in the form of grains, dispersed therein throughout the usable volume thereof. The configuration of Fig. 7 is designed to maintain the operating characteristics of the element generally constant notwithstanding wearing down and consequent reduction of the diameter of the element during use. Thus, as the element is worn down, the same effective width and pressure is applied to the ~Jorkpiece surface.
, ~i Fig. S shows an alternative form of finishing element ;
comprising an outer annular ring 61 of generally uniform resilient abrasive material of the type described in connection with Fig. 7, prefera~ly with a resiliency greater than 75 of the Shore scale.
The inner core fi3 may be constructed of natural rubber, for example, for use in polishing applications. For use in grinding applications, however, the inner core 63 should be formed of metal or hard plastic or similar material to provide precision mounting of the element on a mounting shaft, for accurate grinding. It is appreciated that ~hen the finishiny elements of the type described herein are used for grinding, the resiliency will be less than in polishing applications and the abrasive will be substantially rougher.
Fig. 9 illustrates the use of a conically shaped finishing element of generally uniform resilient abrasive composition. In the illustrated embodiment, the element is arranged such that its radius about its axis II - II of rotation increases with an increasing d,stance from the axis I - I of rotation of the housing. Thus the elen~nt is particularly suited for finishing of interior corners.
Alternatively the finishing ele~ent of Fig. 9 may be oriented oppositely such that its radius about its axis II - II of rotation increases with an increasing distance from axis I - I. Thus the absolutc value of the velocity of rotation at all points along the element is ~enerally the same.
According to an alternative embodiment of the ~invention, the finishing elements may comprise a relatively soft resilient elastic base formed with an abrasive outer surface. The base may be a resir10id, rubber or a porous polyurethane. The abrasive may conlprise grains of diamond, borozone or silicone carbide, for example.
R-ference is now made to Fi~s. lOA and lOB uhic:~ show a ' I
I
~ ~71~S~ ( ;, finishing de~ice constructed and operative in accordance with an en-,bodiment of the present invention and comprising a base 200 on which are mounted at least two finishing elements 210 and 211. Elemcnts 2l0 and 211 are arranged so as to simultaneously contact a rotating workpiecc 212 mounted for rotation on a conventional lathe such as a ~tal lathe. ~ase 200 is in turn rotatably mounted by means of mGunting means 201 comprising a pin and sprocket 202 and a biasing spring 204 or simi7ar suitable apparatus onto a tool holder 205 which mdy be inserted into a conventional tool holidng clamp on the lathe.
Biasing s~ring 204 is operative to maintain the finishing elements in operative engasement with the workpiece surface.
Elements 21~ and 211 are interconnected by a transmission typic~lly co~prising a pair of gears 209 which engage corresponding sedrs 213 and 2'5, having different numbers of teeth, which ~ears are mounted onto elements 210 and 211 respectively. This arrangement ir,sures that elem nts 210 and 211 move in respective opposite dir~stions at different speeds against the workpiece, thus providing enhanced finishing action. Preferably the faster one of the finishing el~ments ~ves together with the workpiece in a generally non-slipping engagement, while the other moves against the w~rkpi~e surface. Alternatively elements 210 and 211 may be caused tc move in the same direction at different speeds.
It is noted that the embodiment of Fig. 4B, for example, may be constructed with a similar transmission.
It is noted that finishing elements 210 and 211 are generally sur~ounded by a housing 220 which defines a collector for particulate matter produced by wearing down of the finishing elements. Housing 220 is designed to retain as much as possible of such particulate matter which is propelled inwardly thereto by the adjacent inward rctation of the finishing elements 210 and 211. Bottom and top edges 222 are dis,oosed adjacent the finishing elements to discourage escape of the particulate matter.
. . .
. ~, t .
Referring particularly to Fig. lOB it is noted that th~ finishing elements 210 and 211 are located at one side of the apparatus at collector housing 220. Adjacent thereto in the ~:liddle of the apparatus indicated by reference numeral 224, there are provided the mounting bearings for the finishing elements.
At location 226, entirely sealed from the outside for safety, are proYided the gears 209, 213 and 215.
It is a particular feature of the present invention that the gear ratio of the transmission is selected such that the ratio of the surface speeds of finishing elements ~10 to element 211 is a~ least 1.1.
It is noted that enhanced surface quality may be realized by moving ~he finishing apparatus transversely along the workpiece in opposite directions.
It is appreciated that the apparatus of Figs. lOA and lOB y may be used also for finishing the flat end face of a surface of rota~ion mounted on a lathe by arranging the housing such that elements 210 lie against the flat face. A high quality finish on the surface of rntation may be realized by back and forth movement of the tool axially along the workpiece. This is equivalent to operation of a rnilling l~chine in opposite directions in the embodiment of Fi~
Reference is now made to Fig. 11 which illustrates a finishing tool particularly suitable for the finishing of internal , surfaces of a workpiece. A workpiece 300 having formed therein a bore 30~, whose 1nner surface it is sousht to finish, is secured in the chuck (not shown) of a conventional lathe for rotation about an axis 304. The finishing tool, indicated generally by reference nur,leral 310 comprises a tool holder 312 which is secured in an appropriate mounting socket (not shown) arranged on the lathe. A
finishing assembly 313 is mounted onto tool hol~er 312 at a selectable i l i~
angular disposition thereto by means of a securing bolt 314.
I.oosening of bolt 314 permits rotation of finishing assembly 313 !
relative to tool holder 312 to define a desired angle with axis 304. ~
Spindle assembly 317 defines a mounting location 322 arranged ~^
symmttrically about axis 320. A selected fin;shing head 324 may be 1' mounted at location 322 onto spindle assembly 317 for rotation about ,'r axis 320 and may be secured onto the spindle assembly by means of a retaining screw 326.
Finishing head 324 is arranged to have a tapered confiquration defining a rectilinear generatrix 328. A tapered finishing head of truncated conical configuration is employed herein as illustrated.
It is noted that the finishing tool is a passive element ~3 and engages in a rolling-slipping motion against the workpiece as ~i is the case in the embodiments of the invention described above.
Reference is now made to Figs. 12A and 12B which illustrate a spindle assembly 600 and associated tool holder mounting means 602 ,-in alternative selectable positions with respect to a workpiece 604 m~unted on a lathe (not shown). The mounting means comprises a pair ~'~
Gf channels 606 and 608 angled with respect to each other by a ~, predeternlined an,ount, onto which a mounting element 607 fixedly attached to spindle assembly 600 may be selectably mounted for selectable ;' anguiar disposition of the spindle assembly and the finishing head 610 with respect to the workpiece. Fig. 12A indicates an orientation l~
where the axes of rotation of the workpiece and of the finishing head -lie in the same plane, while Fig. 12B illustrates an orientation wherein the two axes of rotation lie in different planes.
It will be appreciated by persons skilled in the art that the invention is not limited to what has been specifically shown and ,~
described herein. Rather, the scope fo the present invention is ~.
defined only by the claims which follow:
r , .
,. ~
768~1 Fig. 1 is a pictorial illustration of finishing apparatus associated with a workpiece and mounted onto a rotary milling machine of conventional construction;
- 2a -.,.~-~
;, !
1~7685~ I
Fig. 2 is a side view illustration of a finishing device constructed and operative in accordance with an embodiment of the invention;
F;g. 3 is a bottom view of the finishing device of Fig. 2;
Figs. 4A is a bottom view illustration of an alternative embodiment of a finishing device;
Fig. 4B is a schematic illustration of a further alternative embodiment of a finishing device;
Fig. 5 is a detailed illustration of a portion of a finishing device;
Fig. 6 is a partially cut away illustration of a finishing device;
Figs. 7, 8 and 9 each illustrate an embodiment of a finishing element;
Fig. lOA is a sectional side view illustration of a finishing device useful with a lathe or other turning machine;
Fig. lOB is a plan view of the device of Fig. lOA
taken in a direction indicated by an arrow B.
Fig. 11 is a side view of a fin;sh;ng tool for the interior surface of a workpiece, and Figs. 12A and 12B illustrate two alternative mounting orien~ations for an adjustably positionable finishing tool constructed and operative in accordance with an embodiment of the present invention.
The present in~ention provides finishing apparatus which may be em?loyed selectably for grinding~and polishing by suitable selection of the characteristics of the resi~ient abrasive finishing element. When used for polishing or grinding, sufficient pressure is provided such that the finishing element is compressed by approximately 30 - 300 microns thereby producing an area rather than line contact between the finishing element and the workpiece surface. Such a polishing technique provides a reduction of approximately 0.0005 mm and provides an extremely high quality surface finish of the order of between 16 and 2 microinch r.m.s., and preferably up to 4 - 2 microinch r.m.s.
,t76~
Such a grinding technique provides a reduction of approximately 5 - 50 microns.
It is appreciated that the finishing element in one embodiment of the invention undergoes a complex motion with respect to the workpiece which greatly adds to the quality of the surface finish. This complex ~otion comprises the rotation of the housing or base onto which the finishing element is mounted, the rotation of each finishing element about its own axis and the motion of the workpiece on a moveable table relative to the polishing element.
According to a preferred embodiment of the invention, the finishing technique includes rotation of the base or housing in opposite directions which may correspond to opposite directions of the workpiece movement on the moving table.
Reference is now made to Fig. 1 which illustrates finishing apparatus constructed in accordance with an embodiment of the present invention in operative association with a conventional milling machine for rotational engagement under pressure with a workpiece. The finishing apparatus is indicated generally by reference numeral 1 and comprises a body portion 3 and a shank portion 5 ~hich is insertable into the chuck of the milling machine 7 for rotation selectably in opposite directions about the spindle axis I - I of the milling machine, the body portion 3 and shank portion 5 constitute a mounting member with the shank portion 5 providing a means for attachment to the milling machine 7. The workpiece, 64, is preferably mounted on a movable table 65 associated with the milling machine.
Normally the finishing apparatus is rotated initially in a first direction while the movable table moves in a first longitudinal direction. Thereafter, as the table returns in an opposite direction, the rotation of the finishing apparatus may be in an opposite direction. This two direction capability provides evenly, randomly directly finishing marks.
The pressure engagement of the finishing apparatus with the workpiece surface is illustrated in ~ig. 1 by the extent 67 to which the finishing element indicated by reference numeral 68 is compressed when it engaged the workpiece surface. As noted above, this compression is approximately 30 - 300 microns. Preferably the pressure is exerted perpendicular to the workpiece surface.
Reference is now made to Figs. 2 and 3 and which illustrate the finishing apparatus of the present invention in greater detail. The apparatus comprises a housing base 71 which is fixedly attached to a shank 73 and supports a housing top portion 74 and bottom portion 76. Disposed !' mainly within the housing are a pair of finishing elements 75, typically in the form of annular disks. Elements 75 are mounted rigidly onto respective axles 77 which in turn are bearing mounted within the housing for relatively free rotation with respect thereto. The axes of rotation of both finishing elements 75 are identical and intersect with the axis of rotation of the housing indicated by reference numeral 79, as seen in Fig. 3.
It is a particular feature of the preferred embodiment of the present invention that housing top and bottom portions 74 and 76 together define means for collecting particulate matter which is produced as the result of the wearing down of the resilient finishing elements.
; As seen in Fig. 3, the finishing elements 75 are disposed mainly above the bottom surface of bottom housing portion 76 and only a portion thereof extends outside of the housing, through openings 81 formed in the bottom surface.
Openings 81 are constructed to be of as small an area as possible and therefore have a width only slightly greater than that of the finishing elements, sufficient to prevent interference with the free rotation thereof. The length of the openings is less than the diameter of the finishing elements. Thus particulate matter generated in a :
-- 5 ~
~7hr~
~ 3~3 finishing operation from wear of the finlshing element is gathered into the interior of the housing bottom portion 76 so as not to interfere with the finishing and not to provide uneven results and cause damage to the apparatus.
According to a preferred embodiment of the invention, illustrated schematically in Fig. 4A, the axes of rotation of the finish;ng elen~ents 75 are offset from each other and do not Is intersect axis 79. This non-intersection feature provides an additional vector moment of motion between the finishing element and the workpiece surface when housing base 71 is driven in rotary pressurized motion relative to the workpiece surface.
Fig. 4B illustrates finishing apparatus constructed and operative in accordance with a variation of the embodiment of Fig. 4A. Here finishing elements 80 and 82 are not mounted for independent free rotation relative to the housing 84, as in Fig. 4A but rather are interconnected by a transmission 86, typically comprising an odd or even number of gears. An even i~;
number of gears comprising gears 88, 90, 92 and 94, for example, is preferred since it provides rotation of elements 80 and 82 in respective opposite directions for enhanced finishing action.
It is noted that finishing elements 80 and 82 are offset by different i amounts from the rotation axis 96 of the housing, thus producing different speeds of rotation in the finishing elements, were the elements not connected by a fixed transmission. It is appreciated that the transmission may be constructed such that a non-unitary fixed ratio of speeds is maintained between the two finishing , elements. The two finishing elements may be constructed to be of different widths and to have differing abrasive characteristics. ~
Fig. 5 illustrates a preferred construction of a ~, portion of the bottom housing portion 76 wherein a recess 85 ;s ' .
, -6- ;~
.~
k defined at the inner periphery of the portion 76 for collection ' of particulate matter along the outermost portions of the interior of the housing under the influence of centrifugal forces produced by the high speed rotation of the housing during operation. Portions 87 of the housing bottom surface adjacent the finishing elements are bent upwardly to define a barrier for preventing, insofar as possible, particulate matter from escaping from the housing. The bottom portion 76 is constructed to be removable for easy cleaning.
.
A further development of the apparatus of Fig. 5 is illustrated in Fig. 6 and comprises a housing wherein the bottom portion 53 thereof is selectably positionable relative to finishing elements 75 in order to compensate for wear therein, and the resulting significant decrease in their diameter. Bottom portion 53 is spring mounted onto the housing base 71 by means of a pair of bent leaf springs 55 and is secured to the housing base by means of a screw fastener 57. The extent to which the screw fastener 57 is inserted into a corresponding socket 59 formed in the housing base 71 determines the relative disposition of the bottom surface of the bottom portion 53.
Figs. 7, 8 and 9 illustrate different embodiments of finishing elements constructed and operative in-accordance with an embodiment of the present invention. The element of Fig. 7 is of generally annular configuration having a truncated conical cross section of increasing width with decreasing radius and is formed of a resilient material, typically rubber based, having abrasive material, typically in the form of grains, dispersed therein throughout the usable volume thereof. The configuration of Fig. 7 is designed to maintain the operating characteristics of the element generally constant notwithstanding wearing down and consequent reduction of the diameter of the element during use. Thus, as the element is worn down, the same effective width and pressure is applied to the ~Jorkpiece surface.
, ~i Fig. S shows an alternative form of finishing element ;
comprising an outer annular ring 61 of generally uniform resilient abrasive material of the type described in connection with Fig. 7, prefera~ly with a resiliency greater than 75 of the Shore scale.
The inner core fi3 may be constructed of natural rubber, for example, for use in polishing applications. For use in grinding applications, however, the inner core 63 should be formed of metal or hard plastic or similar material to provide precision mounting of the element on a mounting shaft, for accurate grinding. It is appreciated that ~hen the finishiny elements of the type described herein are used for grinding, the resiliency will be less than in polishing applications and the abrasive will be substantially rougher.
Fig. 9 illustrates the use of a conically shaped finishing element of generally uniform resilient abrasive composition. In the illustrated embodiment, the element is arranged such that its radius about its axis II - II of rotation increases with an increasing d,stance from the axis I - I of rotation of the housing. Thus the elen~nt is particularly suited for finishing of interior corners.
Alternatively the finishing ele~ent of Fig. 9 may be oriented oppositely such that its radius about its axis II - II of rotation increases with an increasing distance from axis I - I. Thus the absolutc value of the velocity of rotation at all points along the element is ~enerally the same.
According to an alternative embodiment of the ~invention, the finishing elements may comprise a relatively soft resilient elastic base formed with an abrasive outer surface. The base may be a resir10id, rubber or a porous polyurethane. The abrasive may conlprise grains of diamond, borozone or silicone carbide, for example.
R-ference is now made to Fi~s. lOA and lOB uhic:~ show a ' I
I
~ ~71~S~ ( ;, finishing de~ice constructed and operative in accordance with an en-,bodiment of the present invention and comprising a base 200 on which are mounted at least two finishing elements 210 and 211. Elemcnts 2l0 and 211 are arranged so as to simultaneously contact a rotating workpiecc 212 mounted for rotation on a conventional lathe such as a ~tal lathe. ~ase 200 is in turn rotatably mounted by means of mGunting means 201 comprising a pin and sprocket 202 and a biasing spring 204 or simi7ar suitable apparatus onto a tool holder 205 which mdy be inserted into a conventional tool holidng clamp on the lathe.
Biasing s~ring 204 is operative to maintain the finishing elements in operative engasement with the workpiece surface.
Elements 21~ and 211 are interconnected by a transmission typic~lly co~prising a pair of gears 209 which engage corresponding sedrs 213 and 2'5, having different numbers of teeth, which ~ears are mounted onto elements 210 and 211 respectively. This arrangement ir,sures that elem nts 210 and 211 move in respective opposite dir~stions at different speeds against the workpiece, thus providing enhanced finishing action. Preferably the faster one of the finishing el~ments ~ves together with the workpiece in a generally non-slipping engagement, while the other moves against the w~rkpi~e surface. Alternatively elements 210 and 211 may be caused tc move in the same direction at different speeds.
It is noted that the embodiment of Fig. 4B, for example, may be constructed with a similar transmission.
It is noted that finishing elements 210 and 211 are generally sur~ounded by a housing 220 which defines a collector for particulate matter produced by wearing down of the finishing elements. Housing 220 is designed to retain as much as possible of such particulate matter which is propelled inwardly thereto by the adjacent inward rctation of the finishing elements 210 and 211. Bottom and top edges 222 are dis,oosed adjacent the finishing elements to discourage escape of the particulate matter.
. . .
. ~, t .
Referring particularly to Fig. lOB it is noted that th~ finishing elements 210 and 211 are located at one side of the apparatus at collector housing 220. Adjacent thereto in the ~:liddle of the apparatus indicated by reference numeral 224, there are provided the mounting bearings for the finishing elements.
At location 226, entirely sealed from the outside for safety, are proYided the gears 209, 213 and 215.
It is a particular feature of the present invention that the gear ratio of the transmission is selected such that the ratio of the surface speeds of finishing elements ~10 to element 211 is a~ least 1.1.
It is noted that enhanced surface quality may be realized by moving ~he finishing apparatus transversely along the workpiece in opposite directions.
It is appreciated that the apparatus of Figs. lOA and lOB y may be used also for finishing the flat end face of a surface of rota~ion mounted on a lathe by arranging the housing such that elements 210 lie against the flat face. A high quality finish on the surface of rntation may be realized by back and forth movement of the tool axially along the workpiece. This is equivalent to operation of a rnilling l~chine in opposite directions in the embodiment of Fi~
Reference is now made to Fig. 11 which illustrates a finishing tool particularly suitable for the finishing of internal , surfaces of a workpiece. A workpiece 300 having formed therein a bore 30~, whose 1nner surface it is sousht to finish, is secured in the chuck (not shown) of a conventional lathe for rotation about an axis 304. The finishing tool, indicated generally by reference nur,leral 310 comprises a tool holder 312 which is secured in an appropriate mounting socket (not shown) arranged on the lathe. A
finishing assembly 313 is mounted onto tool hol~er 312 at a selectable i l i~
angular disposition thereto by means of a securing bolt 314.
I.oosening of bolt 314 permits rotation of finishing assembly 313 !
relative to tool holder 312 to define a desired angle with axis 304. ~
Spindle assembly 317 defines a mounting location 322 arranged ~^
symmttrically about axis 320. A selected fin;shing head 324 may be 1' mounted at location 322 onto spindle assembly 317 for rotation about ,'r axis 320 and may be secured onto the spindle assembly by means of a retaining screw 326.
Finishing head 324 is arranged to have a tapered confiquration defining a rectilinear generatrix 328. A tapered finishing head of truncated conical configuration is employed herein as illustrated.
It is noted that the finishing tool is a passive element ~3 and engages in a rolling-slipping motion against the workpiece as ~i is the case in the embodiments of the invention described above.
Reference is now made to Figs. 12A and 12B which illustrate a spindle assembly 600 and associated tool holder mounting means 602 ,-in alternative selectable positions with respect to a workpiece 604 m~unted on a lathe (not shown). The mounting means comprises a pair ~'~
Gf channels 606 and 608 angled with respect to each other by a ~, predeternlined an,ount, onto which a mounting element 607 fixedly attached to spindle assembly 600 may be selectably mounted for selectable ;' anguiar disposition of the spindle assembly and the finishing head 610 with respect to the workpiece. Fig. 12A indicates an orientation l~
where the axes of rotation of the workpiece and of the finishing head -lie in the same plane, while Fig. 12B illustrates an orientation wherein the two axes of rotation lie in different planes.
It will be appreciated by persons skilled in the art that the invention is not limited to what has been specifically shown and ,~
described herein. Rather, the scope fo the present invention is ~.
defined only by the claims which follow:
r , .
Claims (16)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Apparatus for effecting high tolerance finishing of a workpiece surface comprising:
a mounting member including attachment means suitable for attachment to rotary drive apparatus for rotation of the mounting member about a first axis;
at least one resilient abrasive finishing element rotatably mounted on said mounting member for motion relative to said workpiece surface in a plane perpendicular to said first axis;
bearing means supporting said at least one finishing element on said mounting member for free rotation of said at least one finishing element relative to said mounting member; and means for collecting particulate matter generated during a finishing operation from wear of said finishing element mounted on said mounting member;
said at least one resilent abrasive finishing element comprising an annular body of uniformly intermixed resilient and abrasive substances.
a mounting member including attachment means suitable for attachment to rotary drive apparatus for rotation of the mounting member about a first axis;
at least one resilient abrasive finishing element rotatably mounted on said mounting member for motion relative to said workpiece surface in a plane perpendicular to said first axis;
bearing means supporting said at least one finishing element on said mounting member for free rotation of said at least one finishing element relative to said mounting member; and means for collecting particulate matter generated during a finishing operation from wear of said finishing element mounted on said mounting member;
said at least one resilent abrasive finishing element comprising an annular body of uniformly intermixed resilient and abrasive substances.
2. Apparatus according to claim 1 and wherein said mounting member defines at least one axis of rotation for said polishing element.
3. Apparatus according to claim 2 and wherein said at least one axis comprises first and second axes, said mounting member being arranged for rotation about said first axis and said polishing element being arranged for rotation relative to said mounting member about said second axis.
4. Apparatus according to claim 3 and wherein said first and second axes are intersecting.
5. Apparatus according to claim 3 and wherein said first and second axes are non-intersecting.
6. Apparatus according to claim 1 and wherein said mounting member defines a housing.
7. Apparatus according to claim 1 and wherein said housing constitutes means for collecting particulate matter generated during a finishing operation from wear of said finishing element mounted on said mounting member.
8. Apparatus according to claim 1 and also comprising means for providing pressure engagement between said at least one polishing element and said workpiece surface.
9. Apparatus according to claim 8 and wherein said providing means comprises means for providing rotation of said mounting member in opposite directions.
10. Apparatus according to claim 7 and wherein said collecting means comprises a housing mounted onto said mounting member and defining at least one rectangular opening at the bottom portion thereof, said at least one finishing element being disposed mainly within said housing and extending partially through said at least one rectangular opening, said at least one rectangular opening having a length which is less than the diameter of said at least one finishing element.
11. Apparatus according to claim 1 and wherein the radial depth of said annular body is at least as great as its width.
12. Apparatus according to claim 1 and wherein the resilient and abrasive substances are selected in order to provide a surface finish of 2-4 microinch rms.
13. Apparatus according to claim 8 and wherein said means for providing pressure engagement is operative to produce a compression of 200-300 microns in the overall diameter of said at least one finishing element during operation against a workpiece.
14. Apparatus according to claim 8 and wherein said means for providing pressure engagement is operative to provide area contact between said finishing element and a workpiece surface.
15. Apparatus according to claim 10 and wherein said bottom is selectably positionable with respect to the remainder of said housing.
16. Apparatus according to claim 10 and wherein the interior of said housing is configured to define a recess for collection of particulate matter produced during operation.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8123302A GB2103128B (en) | 1981-07-30 | 1981-07-30 | Surface finishing |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1176851A true CA1176851A (en) | 1984-10-30 |
Family
ID=10523566
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000385058A Expired CA1176851A (en) | 1981-07-30 | 1981-09-02 | Apparatus and method for surface finishing of a workpiece |
Country Status (6)
| Country | Link |
|---|---|
| AU (1) | AU7460981A (en) |
| CA (1) | CA1176851A (en) |
| DE (1) | DE3131753A1 (en) |
| FR (1) | FR2511627B1 (en) |
| GB (1) | GB2103128B (en) |
| SE (1) | SE441901B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| USRE34014E (en) * | 1983-05-11 | 1992-08-04 | Udviklingscentret Hansen & Hundebol A/S | Method and apparatus for finishing surfaces |
| EP0208671B1 (en) * | 1985-06-24 | 1989-08-16 | DIAMANT BOART Société Anonyme | Surfacing tool with rollers |
| DE3734318A1 (en) * | 1986-10-17 | 1988-04-28 | Univ Magdeburg Tech | Device for removing excess material |
| DE8815854U1 (en) * | 1988-12-21 | 1989-02-02 | Maho Ag, 8962 Pfronten, De | |
| DE29508657U1 (en) * | 1995-05-24 | 1995-09-14 | Behr Rainer | Grinding machine |
Family Cites Families (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DD7704A (en) * | ||||
| US1498224A (en) * | 1924-06-17 | Brick-cleaning machine | ||
| DE468719C (en) * | 1928-11-17 | Georg Siguda | Additional grinding device for grinding machines with vertical rotating grinding spindle carrying the grinding tool with cardan joint | |
| US1011991A (en) * | 1911-03-13 | 1911-12-19 | Jacob Moser | Apparatus for cutting washers from boiler-caps. |
| BE399375A (en) * | 1932-12-22 | |||
| US2054311A (en) * | 1932-12-27 | 1936-09-15 | Youngstown Sheet And Tube Co | Interior bead trimmer |
| BE414313A (en) * | 1936-03-11 | |||
| GB478180A (en) * | 1937-07-05 | 1938-01-13 | Harry Randall | Method of manufacturing grinding rings from emery and a medium made of raw rubber |
| US2259685A (en) * | 1941-02-01 | 1941-10-21 | William C Graves | Abrading device |
| FR913884A (en) * | 1945-08-14 | 1946-09-23 | Machine for planing, dressing and polishing granite, marble and all other stones | |
| US2450157A (en) * | 1946-08-23 | 1948-09-28 | Peckett Samuel Charles | Means for preparing true surfaces |
| DE801498C (en) * | 1949-07-15 | 1951-01-08 | Karl Dipl-Ing Fickert | Surface grinding and polishing machine with planetary rotating grinding wheels |
| US2885766A (en) * | 1955-06-06 | 1959-05-12 | Cincinnati Milling Machine Co | Face milling cutter |
| GB821742A (en) * | 1957-05-09 | 1959-10-14 | Fritz Dierks | Improvements in paint removing devices |
| GB956762A (en) * | 1962-04-16 | 1964-04-29 | Hammond Machinery Builders Inc | Polishing and buffing apparatus |
| FR87293E (en) * | 1965-02-11 | 1966-07-08 | Device for grinding and polishing surfaces such as stones | |
| US3946525A (en) * | 1974-11-18 | 1976-03-30 | John Ford Harper | Automatic buffing machine |
| DE8117519U1 (en) * | 1981-06-13 | 1981-11-05 | Kammerer, Hans, 8592 Wunsiedel | GRINDING HEAD FOR HARD ROCK |
-
1981
- 1981-07-30 GB GB8123302A patent/GB2103128B/en not_active Expired
- 1981-07-30 SE SE8104609A patent/SE441901B/en not_active IP Right Cessation
- 1981-08-11 DE DE19813131753 patent/DE3131753A1/en not_active Withdrawn
- 1981-08-21 FR FR8116071A patent/FR2511627B1/en not_active Expired
- 1981-08-25 AU AU74609/81A patent/AU7460981A/en not_active Abandoned
- 1981-09-02 CA CA000385058A patent/CA1176851A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| SE441901B (en) | 1985-11-18 |
| SE8104609L (en) | 1983-01-31 |
| FR2511627B1 (en) | 1986-12-26 |
| GB2103128B (en) | 1986-03-19 |
| AU7460981A (en) | 1983-03-03 |
| FR2511627A1 (en) | 1983-02-25 |
| DE3131753A1 (en) | 1983-02-24 |
| GB2103128A (en) | 1983-02-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4993194A (en) | Grinding disks for profiling cylindrical worms | |
| US3877177A (en) | Device for machining spherical surfaces | |
| US4677793A (en) | Method and apparatus for high tolerance polishing of a workpiece surface | |
| US5052154A (en) | Grinding wheel having adjustable axial dimension | |
| CA1176851A (en) | Apparatus and method for surface finishing of a workpiece | |
| EP0765712A1 (en) | Wheel truing device | |
| US2528621A (en) | Grinding wheel truing apparatus | |
| US4592399A (en) | Rotary cutter assembly | |
| GB2148757A (en) | Abrasive surface finishing | |
| US4862646A (en) | Apparatus and method for production of single element toric lenses of very small proportions | |
| KR950704088A (en) | IMPROVEMENTS IN OR RELATING TO HE MANUFACTURE OF ROTARY VALVES | |
| US2042759A (en) | Valve seat grinding machine | |
| KR920011648A (en) | Reciprocating rotary diamond truing and dressing tools and how to use them | |
| CA1307400C (en) | Quick change lens tool | |
| JPS632287Y2 (en) | ||
| JPH08323618A (en) | High accurate-high efficient truing and dressing methods for diamond grinding wheel by composite grinding wheel | |
| JPS6312912Y2 (en) | ||
| DE3801540A1 (en) | Precision surface-grinding air bearing | |
| JP3271334B2 (en) | Ceramic cutting tool grinding equipment | |
| JPH07186017A (en) | Grinding method and grinder for end surface plane part of disc-shaped work | |
| JPS58211854A (en) | Chamfering method for rotary valve | |
| SU884972A1 (en) | Flat grinding method | |
| JPH0335065B2 (en) | ||
| JPH02284874A (en) | Grinding stone | |
| JPS6034258A (en) | Vibro-grinding method in centerless feed grinding |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |