US2910811A

US2910811A - Grinding and polishing

Info

Publication number: US2910811A
Application number: US676620A
Authority: US
Inventors: Whitesell Harry
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-08-06
Filing date: 1957-08-06
Publication date: 1959-11-03
Anticipated expiration: 1976-11-03

Description

Nov. 3, 1959 H. WHITESELL GRINDING AND POLISHING Filed Aug. 6, 1957 HarryWhH'ese H,

Unite States. Patent GRINDING AND POLISHING Harry Wlu'tesell, Chicago, Ill.

Application August 6, 1957, Serial No. 676,620

12 Claims. (Cl. 51-267) This invention relates to improvements in grinding and polishing, and the like. More particularly, the invention relates to improvements in grinding and polishing operations in which the abrasive surface against which the work being treated is held, is moved at a comparatively high rate of speed, although it will also become apparent that said improvements are not limited to high speed surface operations. Such speeds as presently being practised may be of the order of ten to twelve thousand feet per minute, or even higher. Likewise, the rotative speeds of the wheels carrying, or over which the abrasive surface travels must be of corresponding values, taking account of the wheel sizes used. Thus, in the case of a wheel of diameter of eighteen inches and having a peripheral speed of twelve thousand feet per minute the rotative speed will be of the order of 2545 r.p.m. The centrifugal forces developed at such speeds and with such wheel sizes are very large. The features ofinvention herein disclosed may be advantageously used in connection with such high speed operations, but said features are also usable in connection with much lower speed operations as for example, 1000 ft./min., or less.

The features of the present invention are useful in connection with operations in which the abrading is produced by direct contact of the work with the surface of an abrading wheel, in which type of operation such wheel surface is provided with abrasive, either as a surface application or as a component of the wheel material itself. The features of the present invention are also applicable to operations in which an abrasive belt is travelled over a contact wheel, the work being held against the surface of such travelling belt, generally at a location where such belt is riding over the wheel surface. In the case of such belt type operation the abrasive material carried by such travelling belt has a linear speed around the wheel perimeter equal to the belt speed.

It has been found desirable, and in many cases necessary to deliver to the travelling abrasive surface some form of liquid so that the abrasive particles are wetted thereby at the cutting area. Due to the high rate of travel of such abrasive surface great difficulty has been encountered in actually delivering such liquid agent into wetting contact with the belt or wheel surface, or in keeping such liquid agent on such surface if it has, in fact actually been possible to truly effect wetting contact thereof with such surface. A prime difficulty in effecting actual delivery of such liquid agent to the travelling surface has arisen from the following conditions:

A surface travelling at high speed produces a drag on the surrounding atmosphere. Such drag depends largely on the smoothness of the travelling surface, but the rate of travel is a prime factor in producing such drag. As the rate of travel is increased such drag increases rapidly. Accordingly, it has been found that at the necessary speeds for abrasion such drag becomes high. The very fact that the surface is non-smooth and of an abrasive nature multiplies the drag, and thus produces a layer or film of air 2,910,811 Patented Nov. 3, 1959 travelling along and with the abrasive surface. The very rate of travel of such film of air brings such film to a condition of high resistance to penetration of such film by any object seeking to penetrate it for producing actual contact with the travelling abrasive surface. Additionally, any liquid material which might penetrate such rapidly travelling film would then encounter the roughened abrasive surface with corresponding violent contacts of the liquid particles with the abrasive surface particles. Such high velocity contacts would also tend to drive any droplets of the liquid away from the very surface which they were intended to wet. Furthermore, the centrifugal forces developed by travel at such linear rates as suggested above, and with the angular velocities produced at the wheel periphery are such that any droplets which may have reached the abrasive particles would be expelled from the abrasive surface as a mist or fine cloud.

For the foregoing and other reasons it has been found practically impossible to maintain a wetted condition of the abrasive surface by conventional operations which primarily depend on directing the liquid body against the travelling surface or against the air film which prevents actual substantial contact of such wetting material with the surface intended to be wetted.

it is a prime object of the present invention to provide a method and the means to ensure effective delivery of the liquid material to the abrasive surface and to also ensure that such material, so delivered to such surface will retain its effective adherence to the abrasive particles and perform its intended function in conjunction with the abrasive particles during the abrading operation. The following operations are also noted in connection with the foregoing:

When the belt type operation is used it is necessary to provide an idler wheel, the belt travelling over such idler wheel and the contact wheel. Such idller wheel thus used, is generally crowned and adjustable so that the tracking of the belt over the contact wheel may be controlled. Nevertheless, it frequently is found ditficult to effectively control such tracking of the contact wheel, especially when the belt is of narrow Width, such as a few inches. This is especially true in the case of contact wheels which are not crowned but are provided with flexible peripheral surfaces. It is also true in the case of contact wheels which are provided with contoured surfaces to conform to the contour of the work being treated. The present improvements provide a supplemental control of the belt during its travel over the contact wheel. Such supplemental control of the belt travel is provided at a location very close to the point of entry of belt travel onto the contact wheel.

My present improvements include the provision of a supplemental wheel riding on and pressed against the belt on that run of the belt travelling towards the contact wheel, and close to the point of entry of the belt onto such contact wheel. This supplemental wheel is preferably crowned so that it depresses the central portion of the travelling belt lower than the edges of such belt with consequent production of a slight valley facing outwardly away from the axis of contact wheel rotation. Then, as the belt enters onto the surface of the contact wheel such sight valley is flattened out, or in case the contact wheel is contoured, an actual reversal of the deflection of the central portion of the belt may be produced, changing such belt from an outwardly facing valley to an inwardly facing valley during the travel over the contact wheel. Such supplemental wheel serves to produce an added control of the belt travel, making it possible to better control the tracking as explained above.

Next, I provide means to introduce the liquid body against the belt surface directly in front of the location of contact of such supplemental wheel with the belt, or with the surface of the abrasive wheel in cases where the abrasive is carried directly by or is impregnated into the material of the wheel surface without interposition of the belt, or in cases where the wheel itself is formed of abrasive material such as vitreous abrasive material. Such introduction of the liquid at such location is conveniently done by a spraying and/ordripping operation, preferably with a rather high pressure spraydirected closely towards the location of engagement of the supplemental wheel with the belt or wheel surface. If needed, a suitable shield may' be provided around the supplemental wheel, such shield coming close to the belt or Wheel surface at each side of the supplemental wheel, leaving only sufficient opening between the end of such shield'and the belt or wheel surface to permit the liquid body to be definitely introduced against the intended surface justbefore such surface is physically contacted by such supplemental wheel. Thereby the liquid body is carried almost immediately to the location of strong pressure between such supplemental wheel and the belt or the wheels surface, with immediate strong pressure of such liquid body against the abrasive surface itself. Such strong pressure will then effect drive of the liquid body well into the interstices between the abrasive particles of the. abrasive surface, thus ensuring effective wetting of such particles by a film of such liquid body material. Having thus effectively deposited such film of the liquid' body onto the abrasive particles such film will adhere strongly to such particles and efiectively resist outward throw by the centrifugal forces developed during radial acceleration around the wheel surface or the surface of the belt. When the surface of the wheel is of abrasive nature and no belt is used, the surface of such wheel being flexible as in the case of a bufiing wheel, by introducing loose abrasive material onto the supplemental wheel said abrasive material will be strongly impregnated into such flexible buffing wheel.

A further effect of the crowning of the supplemental wheel is as follows:

Any tendency for the applied liquid to concentrate at a specific location across the width of the belt or of the abrasive wheel is immediately resisted and counteracted by such crowning of the supplemental wheel, since the effect of such crowning is to force at least some of the trapped liquid body laterally towards the edges or other areas of the belt or of the abrasive wheel, and with production of a substantially even distribution of the liquid body over the entire width of the abrasive carrier. The pressure of the supplemental wheel against the abrasive surface serves to drive the liquid body fully between the abrasive particles since the yieldable or flexible surface of the supplemental wheel ensures effective pressure of such yieldable or flexible wheel surface deep between the abrasive particles carried by such abrasive surface. This ensures wetting of the full exposed surfaces of the abrasive particles instead of merely their extreme end portions as would otherwise be wetted. Thus the present improve ments serve to ensure effective wetting of the full exposed surfaces of the abrasive particles.

It is also noted that the film of air carried along with the belt at its surface, or with the periphery of the wheel in case no belt is used, travels directly into the zone of contact between the supplemental wheel and the abrasive surface, which zone is rapidly closing to zero thickness as the location of engagement between the supplemental wheel and the abrasive surface is reached. Thus such film of interfering air is completely eliminated at the location where the liquid body is to be introduced and carried into the spaces between the abrasive particles. Such film of air is actually turned laterally to the sides of the abrasive carrier, and thus aids in securing desired distribution of the liquid body to all widths of such abrasive surface. This is a distinctive feature of my method and. means. In connection with the foregoing it is also noted that the air of the film above referred to tends to compress into the narrowing space between the abrasive surface and the supplemental wheel, thus producing a cushion against which the further oncoming air of the film is received. Thereby such oncoming air film is actually slowed down just before reaching the location of closure between the supplemental wheel and the abrasive surface. This slowing down also greatly reduces the opposition to penetration of such air film by the liquid body. Such slowing down of the air film also ensures a driving action of the particles of liquid in forward continuing direction clear to the location of actual contact between the supplemental wheel and the abrasive surface with which contact of the supplemental wheel is made. This driving action is due to the inertia of such liquid particles whose specific gravity is many times as great as that of the air film. All of these factors act to make it possible to produce the desired wetting of the abrasive particles by use of the features of my present invention.

A further important feature and object of my present invention is as follows:

During use the abrasive surface receives the material removed from the work body as well as various other foreign ingredients. Such other foreign ingredients may include paint removed from the work body, various oxides and salts and small, almost microscopic chips cut from the work body; Additionally, minute particles of the abrasive particles themselves are broken off and become a portion of the detritus. All such detritus material becomes packed against and into the surface of the abrasive carrier and around the abrasive particles of such carrier. As a consequence the abrading value of the abrasive carrier becomes lowered, and its abrading efficiency is reduced to the point that such carrier must be discarded and a fresh carrier substituted. This is a matter of considerable expense for such replacements. Additionally, the down time of the machine and related equipment, and the time and labor lost in making such replacements are a serious item of expense. It is an important feature of my present invention to greatly reduce such losses. Such improvements are produced as follows: The resilient and elastic surface of the supplemental wheel is compressed against the abrasive surface as I have already explained. This compression causes the surface material of the supplemental wheel to penetrate around the abrasive particles which are themselves adhered to the abrasive carrier, so that intimate contact between the resilient elastic surfacing of the supplemental wheel and the carrier or the foreign material or detritus on such carrier, is produced, the abrasive particles remaining adhered to the carrier itself. The wetting of such elements as already explained, enhances the intimacy of this contact between the surfacing of the supplemental wheel and such detritus material. These operations take place as the clearance between the surface of the supplemental wheel and the abrasive surface is falling to zero. Thus, when the location of maximum pressure between the supplemental wheel and the abrasive surface is reached a substantial pressure has developed between the surface of the supplemental wheel and the abrasive carrier and its detritus material, with full expulsion of air from the area of contact, and with the production of a vacuum cup seal between the supplemental wheel and the carrier and detritus carried thereby. As the travels of the supplemental wheel and such carrier proceed, each elemental area of such wheel commences to withdraw from the proximate elemental area of the carrier, and such withdrawal is produced with a sufiicient force to effect separation of the elemental surfaces from'each other against the resistance due to such vacuum cup sealing effect. Such vacuum cup sealing effect is developed against the detritus materials between the abrasive particles which abrasive particles constitute portions of or are cemented to the abrasive carrier. Experience has shown that the "vacuum cup effect thus produced and existing between the resilient and elastic surfacing of the supplemental wheel, and such detritus material, is greater than the adherence of the detritus material to the carrier. Consequently the detritus material is torn away from the carrier itself and such detritus material then travels circularly with the supplemental wheel until expelled therefrom by centrifugal force and dissipated in all directions.

The abrasive particles of the abrasive surface are cemented or strongly adhered to or constitute portions of the abrasive surface. This adherence is much greater than the vacuum cup effect produced on such cemented abrasive particles by the resilient elastic material of the supplemental wheel. Consequently, as the wheel elemental area separates from the proximate elemental area of the abrasive surface, the abrasive particles are not torn from the carrier to which they are adhered, but they are left in their cemented or adhered relation to such carrier; Thus, only the detritus material is torn away from its condition of being packed around and between the cemented abrasive particles, leaving such abrasive particles cemented or otherwise adhered to the carrier, the detritus material having been thus broken loose and removed from between the abrasive particles of the surface. Thus such abrasive surface is renovated and renewed to its full abrasive quality.

The following function is also noted in connection with the foregoing feature:

This cleaning or clearing operation occurs each time a given elemental area of the abrasive surface comes into engagement with the supplemental wheel. Thus such cleaning or clearing action occurs with great frequency. In fact it occurs once for each abrading contact of the abrasive elemental area with the work body. For this reason the detritus material is never allowed to become excessively collected on any elemental area of the abrasive surface, and is never allowed to become severely packed between the abrasive particles carried by the carrier. Accordingly, the abrasive surface of the carrier is not allowed to become loaded with the detritus material, but is maintained in a clean, efiicient, and highly elfective abrading condition.

Various kinds and compositions and specifications of liquids may be used in the practice of this invention. These include, by way of example only, and not as limitations, except as I may limit myself in the claims to follow, such electronic media quality materials as cutting oil and coolant, cutting waxes, either neat or as solutions, catalytic agents or various kinds, soluble oils, and various other materials of proper freedom of flow, low viscosities, and other requirements. Said materials may also be used either cold or hot, or of various specified temperatures. Water is also frequently used for such purposes.

The yieldable, resilient, elastic surfacings of the supplemental wheel or the abrasive wheel, when used, may also be formed of various materials. Such materials as natural and/or artificial rubbers, auto tread rubbers, Buna rubbers, Hycar rubbers, neoprenes, and many others which are wear and abrasive resistant against their contacts with the abrasive materials of the belt or the abrasive wheel surface, may be used. It is thus evident that I do not intend to limit myself to any specific yieldable, resilient, and/or elastic material or materials, except as I may limit myself in the claims to follow.

Other objects and uses of the invention will appear from a detailed description of the same, which consists in the features of construction and combinations of parts hereinafter described and claimed.

In the drawings:

Figure 1 shows a schematic embodiment of the features of my present invention in a system wherein a belt travelling over a contact wheel and an idler is used, the supplemental wheel being adjustably mounted close to that run of the belt which approaches the contact wheel (being the top run), and provision being made for introducing 6 i the body of liquid or spray into the location between the belt and the supplemental wheel where the clearance is rapidly falling to zero; and in the showing of this figure the contact wheel is shown as provided with a fiat or cylindrical surface of yieldable resilient, or elastic material, the supplemental wheel being crowned and provided with a surface of abrasion resisting, resilient or elastic material and a shield to collect any outthrown liquid body; and in this figure there is also shown provision for adjustably pressing the supplemental wheel against the belt at the desired location and with the desired pressure, as well as provision for adjusting the tension on the belt;

Figure 2 shows a section taken on the line 22 of Figure 1, looking in the direction of the arrows; and there is shown a pump for delivering the liquid body material to the desired zone through a series of spray nozzles directed to that zone; I

Figure 3 shows a section taken on the line 3-3 of Figure 1, looking in the direction of the arrows;

Figure 4 shows another embodiment of the present invention in which no belt is used, the abrasive material being carried directly by the surface of the abrasive wheel, or comprising a constituent of such wheel, as when such wheel is formed of vitreous abrasive material, such abrasive wheel being cylindrical or fiat, or contoured to conform to the work bodys section requirements or contour, whereas the supplemental wheel may be crowned as shown or contoured to correspond to the contour of the abrasive wheel, and such supplemental wheel is provided with an abrasion resisting, resilient or elastic surface to provide an area of functioning contact with the abrasive wheel so that various of the functions and objectives already explained may and will be accomplished;

Figure 5 shows a view taken on the line 55 of Figure 4, looking in the direction of the arrows;

Figure 6 shows a modified form of crowned supplemental wheel, the crown being rounded, and the surface of such wheel being formed or coated. with abrasion resisting, resilient, elastic material; and

Figure 7 shows an enlarged detail of the portions of Figures 1 and 4, wherein the supplemental wheel is in functional area contact with the belt or the abrasive wheel, and this figure shows how, during the travel between the locations of first contacting of the supplemental wheel and such belt or abrasive wheel and the location of disengagement thereof, the surface of the supplemental wheel may and does yield radially inwardly to enable production of the desired functions and objectives.

In the drawing I have shown schematically several embodiments of my present invention. Referring first to Figures 1, 2 and 3, the contact wheel 10 is carried by the shaft 11, which shaft is suitably journalled in bearings. not shown. Such contact wheel usually also serves as the driver of the system for which purpose its shaft is suitably driven at desired speed. The direction of rotation is shown by the arrow. Such contact wheel is preferably surfaced with a yieldable, resilient, elastic surfacing 12, indicated by the stippling in Figures 1- and 3.

In the showing of Figures 1, 2 and 3 a belt 13 travels over such contact wheel, and also over the idler wheel 14. Such idler wheel is shown as being crowned, and as being shiftable towards and away from the contact wheel. To these ends the idler wheel is carried by the shaft 15 which is journalled by the bearings 16 (only one of which is shown in Figure 1). These end bearings are guided for back and forth movement in the sotted supports 17. Each bearing is also provided with an outwardly extending stem 18 which extends through a stationary abutment 19. A compression spring 20 is provided around each such stem, an adjustable abutment nut 21 being threaded onto the stem to thereby compress the spring between such nut and the stationary abutment 19. By this means the tension developed in the belt is forth. movements of the idler wheel necessary during running to produce smooth operation.

Provisions are conventionally made for ensuring proper tracking of the belt on the contact wheel. Details of such provisions need not be disclosed here as various such means are well known in the present art. However, it is here noted that the supplemental wheel now to be disclosed may also serve to aid in securing or ensuring good tracking. Such supplemental wheel is schematically shown at 22. It is provided with a shaft 23 suitably journalled by the journals 24 (only one of which is shown). Preferably such journals 24 are shiftable towards and away from the belt 13. Suitable guides for guiding such shifts are also provided (not shown), but which may be similar to the guiding arran ements provided for the guiding of the idler Wheel as already disclosed. Each such journal is provided with an upwardly extending stem 25 which extends through the stationary abutment 2 6. The compression spring 27 is provided on each such stem, and a nut 28, threaded onto the stem provides means to adjust the spring urge of the wheel shaft downwardly towards the belt. In Figure 1 I have indicated a slight depression of the belt produced by such down thrust of the supplemental wheel.

The supplemental wheel is so located and supported that its location of contact with the belt is very close to the location of entry of such belt onto the contact wheel periphery so that only a short travel of the belt occurs between the supplementary wheel and the contact wheel. This closeness is desirable for several reasons, including the fact that thus the wetted surface of the belt, presently to be detailed, is thus exposed to the air and to possible loss of the liquid body through various agencies such as evaporation, etc., for on y a short distance and interval of travel before such wetted surface portion reaches the location at which the work body is in contact with the belt or wheel surface.

This supplemental wheel is preferably crowned as shown in Figures 1, 2 and 3; and such wheel is also preferably provided with a surfacing of abrasion resisting, resilient, elastic material, as shown at 29, and indicated by the stippling. Accordingly the pressure of such supplemental wheel against the belt surface, or against the abrasive wheel surface, as in other embodiments presently to be referred to, produces an outwardly or upwardly facing V-shaped depression in the belt just in advance of entry of such belt onto the contact wheel. Such depression is almost immediately afterwards rectified as the belt rides onto the contact wheel, or in case such contact wheel is itself also crowned, an actual reversal of the V wi'l occur between the supplemental wheel and the contact wheel. In any case, however, it is emphasized that a strong pressure is developed between the supplemental wheel and the belt surface at the location in advance of entry onto the contact wheel. Due to such strong pressure, and also the fact that the supplemental wheel is surfaced with abrasion resisting, resilient, elastic material, good penetration of the surfacing of such supplemental wheel into and between the abrasive particles on the belt surface is ensured. Such abrasive particles are of very hard material, and are cemented or otherwise adhered to the belt surface. Accordingly, as the belt runs under the supplemental Wheel, which is travelling at belt peripheral or linear speed, the particles of liquid body which is on or very close to the belt surface are forced and crowded down into strong engagement with the belt surface, and due to the yieldable nature of the supplemental wheel surfacing such liquid body material is also carried down around and into strong engagement with each of the abrasive particles cemented to the belt. Thus there is forcibly applied a film of the liquid body directly to each of the abrasive particles, as distinguishedfrom previous attempts to wet such abrasive particles by merely spraying them with such liquid body material.

It is now emphasized that a further and very important difference thus exists between any such mere spraying operation and the operation herein disclosed. This vital difference is as follows:

In the case of the effort to deliver the liquid body through the film of fast moving air close to the surface of the belt or abrasive surface wheel, the carrier by which such liquid body material must be carried and delivered to the abrasive surface is the air blast itself, Accordingly, under such a scheme of operations such air blast carrier must itself penetrate through the air film carried close to the surface of the belt or abrasive wheel, in order to deliver any particles of the liquid body to such abrasive surface, since the particles of such liquid are of microscopic size, being in the form of a spray. Of themselves they have substantially no kinetic energy of velocity to carry them through the film of air travelling close to the abrasive surface. Accordingly, they never do actually wet the abrasive particles but rather they are dissipated into the surrounding atmosphere as a fine mist. This fact is attested to by examina-v tion of an abrasive belt or abrasive wheel towards which, travelling at the intended high linear speed, there has been directed a jet or spray of liquid intended to wet the abrasive surface. Upon examining such abrasive surface after stoppage of its travel it will be found to be dry and show no signs of having been wetted by such spray or jet. On the contrary, examination of the abrasive surface of a belt or abrasive wheel to which has been applied the liquid body according to the teachings of this case it will be found that the abrasive particles of such abrasive surfaces have been thoroughly wetted, and that they retain such wetting for a considerable interval of time after stoppage of the belt or wheed travel, and until drying is produced by natural processes.

As distinguished from such air carrier method of directing the liquid body material towards the abrasive surface the presently disclosed method and means acts to deliver the liquid body material to the abrasive surface by mechanical pressure developed by a sold body, namely, the supplemental wheels surface, and its physical contact with the abrasive surface at the critical area. While it is true that a jet or spray is conveniently used to supply the liquid body material into the zone close to the closing area as already explained, still the actual delivery of such liquid body material to its intended destination is effected by physical pressure developed between two solid bodies. The fact that one or both of such bodies may be and generally are surfaces with yieldable resilient and/or elastic material does not change the underlying principle of the operation, since solid bodies, even though elastic and yieldable, have very different characteristics from those enjoyed by gases and vapors. These facts are too well understood to require further discussion here.

In Figures 1, 2 and 3 I have shown schematically several jets or spray nozzles 30, preferably of small orifices, all supplied by a common manifold 31 extending across the width of the supplemental wheel. The small delivery tips of these nozzles come very close to the closing position or line between the supplemental wheel and the belt or abrasive wheel, but evidently it is impossible to carry them exactly and finally into the infinitesimally thin zone which exists just before final physical contact between the supplemental wheel and the belt or the abrasive wheel occurs. However, due to the air conditions existing at such final very thin zone and the slowing down of air travel at such zone, it has been found that excellent delivery of the liquid body material to its intended destination can be and is produced by the arrange? ments already explained.

Conveniently the liquid body material is supplied under pressure to such manifold by a pump, such as a centrifugal or reciprocating pump 32, drawing its supply from a source, not shown, and delivering its output in tangential fashion as is well understood. Since the supplemental wheel is subject to slight variations of separation axially from the contact wheel, due to vibrations and other forces, although contact is retained with the abrasive belt or with the abrasive surface of the abrasive wheel itself, and since it is desired that the nozzles 30 retain their exact positions with respect to such supplemental wheel, I have shown such nozzles as carried by a bracket 33 which is connected to one of the shaft hearings or other suitable element in such manner that the manifold and nozzles always retain the desired relation to such supplemental wheel. Also, in order to take care of such vibrational and other adjustment changes between the supplemental and contact wheels, while retaining the nozzles in fixed relation to the supplemental wheel, I have shown the section of flexible conduit 34, such as hose or the like, included in the line 35 connecting the pump to the manifold. Also, a valve 36 is indicated for controlling the rate of delivery of the liquid body material to its intended zone. Once the operation has been brought into regular balanced condition such valve may generally be closed at least partially so as to supply the material only at such rate as may be needed to keep the abrasive surfaces properly wetted.

Since some liquid body material will inevitably be thrown by centrifugal force from the supplemental wheel, due to its high peripheral velocity and angular velocity, I have also shown a sheet metal guard 37 encircling such supplemental wheel between the locations 38 and 39 which are close to the surface of the abrasive belt or the abrasive wheel surface as the case may be. Any liquid body material collected by this guard will run off at one or both ends, or may be collected in convenient manner and re-used.

By way of illustration I have indicated a work body in the form of a metal bar 40 in pressed relation to the abrasive wheel or the abrasive 'belt at a point convenient for proper manipulation of such work body.

Figures 4 and illustrate schematically an embodiment wherein the abrasive wheel itself is provided with an abrasive surface against which the work is pressed, there being no abrasive belt riding over such wheel, and in this embodiment the supplemental wheel directly contacts such abrasive wheel with provision for delivering the liquid body material to the closing space between such supplemental wheel and the abrasive wheel under conditions such as already explained. his deemed unnecessary to describe this embodiment in full detail, but for convenience I have legended like parts of this embodiment and that of Figures 1, 2 and 3 with like numerals, but with application of the suffix a." The following comments are, however, proper:

In the present case, since the supplemental wheel is provided, preferably with an abrasion resisting resilient or elastic surface, and since the abrasive wheel may be likewise provided with a resilient surface, it is evident that pressure developed between the two wheels will produce depression of one or both such yieldable surfaces at their locations or areas of contact. In the embodiment now under consideration the supplemental wheel is shown as being crowned, and the abrasive wheel as being of cylindrical surface. Accordingly, when sufficient pressure is developed between such wheels such depression will extend completely across both Wheels, or that one of less width, thus producing the desired contact between the two wheels completely across such wheels. Thus the effects which I have already detailed will be produced for the full width of such wheels. Further, since the supplemental wheel does not contact a travelling surface which is approaching the abrasive wheel from a third, or idler wheel, it is evident that there is no limitation as to the angle at which such supplemental wheel may be set, meaning that the axis of such supplemental wheel may be directly above the axis of the abrasive wheel, or, as in Figure 4, the axis of the supplemental wheel may actually be brought over above the descending peripheral surface of the abrasive wheel. Such placement may be as far over as desired, provided, only that the supplemental wheel does not interfere with the proper application of the work body 40 to the abrasive wheels surface. Thus, with this arrangement the travel of the applied liquid body after its application and before its coming to the work zone may be reduced to a minimum, with consequent benefits in some cases.

Figure 5 shows a view on the line 5--5 of Figure 4, looking in the direction of the arrows, and this Figure 5 emphasizes the fact that the depression produced in the yieldable resilient elastic surface of the abrasive wheel when its surface is yieldable or resilient, by the crowning of the supplemental Wheel, may be carried as far across the abrasive wheel as desired by producing the necessary pressure between the two wheels by the spring adjustment.

Figure 6 shows a face view of a modified form of crowning which may be used for the supplemental wheel. In this case the crowning is rounded into a spherical segment surface, instead of being the conventional double conical surface. Such rounded surface design is desirable for use in some cases.

In Figure 7 I have shown on enlarged scale as compared to previous figures a detail of the area of contact between the yieldable, resilient elastic surface of the supplemental wheel and the abrasive belt surface under the condition that the pressure exerted by the supplemental wheel against such belt surface is suflicient to compress the resilient elastic surfacing of such supplemental wheel enough to produce an appreciable area of contact angularly between said parts. Such area of contact begins at the location 41 where the supplemental wheel first engages the belts surface, and extends to the location 42 where such engagement terminates. The location of maximum compression of the resilient elastic surface of the supplemental wheel is at about the point 43. During wheel surface and belt surface travel from 41 to 43 the elastic surfacing of the supplemental wheel is penetrating deeply into the interstices between the abrasive particles of the belt, and making good contact with the detritus material carried by the belt. Such contact is improved and rendered largely air tight by the wetting of the surfaces, and the air is expelled from between the supplemental wheels surface and that of the belt. Then, as the operation proceeds from the location 43 to the location 42 the elastic surface of the supplemental wheel is expanding or relaxing due to reduction of compression thereof, until the location 42 is reached where definite separation occurs between such surfaces. Due to the vacuum cup engagement between the surfaces there will actually be a small stretching of the elastic surface material of the supplemental wheel, until a condition arrives at which the pull exerted on the elastic surface of the supplemental wheel is sufiicient to drag the surfaces apart, with the removal of the detritus material as already explained in some detail.

The wetting operations herein disclosed are very different from the conventional operation of flushing the cutting tool of a machine tool unit with oil or other coolant. In such previously practised operations the cutting tool is not producing any operation at all comparable to the grinding and/or polishing operations to which the present invention relates, and the flushing of the point of the tool as conventionally practised is for a very different purpose and is effected in a very different manner from the wetting operations herein disclosed, and which have to do with a completely different type of operation, namely, that of acting on and treatmg a comparatively large surface of the work body as compared to the small surface, cutting away, operation performed by such machine tool.

I claim:

1. The. combination with an element having an abrasive surface and means to drive said element for movement of said abrasive surface in a direction of travel towards and past a work abrading location, said surface being provided with fine particles of abrading material, of means to wet said abrasive surface and said abrasive particles at a location in advance of said work abrading location, comprising a supplemental wheel in peripheral engagement with the abrading surface along a narrow Zone of contact parallel to the axis of the supplemental wheel at said location which is in advance of the work abrading location, the abrasive surface and the surface of the supplemental wheel adjacent to the location of peripheral engagement aforesaid providing a'space of generally V-shape between the surfaces with the apex of such V at the location of said peripheral zone means to journal said supplemental wheel for rotation on an axis extending transversely of the direction of travel aforesaid, said supplemental wheel being provided'with a surface of abrasion resisting resilient material, means to urge the supplemental wheel towards the abrading surface to thereby cause the surface of the supplemental wheel to contact with and embrace the particles of abrading material at the wetting location aforesaid, said surface of the supplemental wheel travelling in the same direction as the travel of the abrasive surface at said wetting location and nozzle means having its orifice in position to deliver wetting body material to said V-shaped wetting location and between the abrasive surface and the convex surface of the supplemental wheel, which convex surface is approaching engagement with the abrasive surface and travelling with a component of movement in the direction of travel of the abrasive surface.

2. Means as defined in claim 1, wherein the supplemental wheel is crowned, and wherein the abrasive surface is yieldable at the location of peripheral engagement of the supplemental wheel with such surface, to thereby allow conformity of the abrasive surface with the supplemental wheel surface at such peripheral engagement location.

3. Means as defined in claim 1, wherein the element having an abrasive surface comprises a belt, a contact wheel and an idler wheel, the belt travelling over said two wheels with belt runs extending between the two wheels, and wherein the supplemental wheel is in periph eral engagement with the abrasive surface of the belt at a location in advance of the entry of the belt onto the periphery of the contact wheel.

4. Means as defined in claim 3, wherein the supplemental wheel is crowned, and wherein the contact wheel is provided with a cylindrical surface.

5. Means as defined in claim 3, wherein the supplemental wheel is crowned.

6. Means as defined in claim 1, wherein the abrasive surface comprises the peripheral surface of a wheel, and wherein the work abrading location comprises a 10- cation of the peripheral surface of said wheel, and wherein the supplemental wheel is in peripheral engagement with said wheel at a location in advance of said work abrading location, and wherein the supplemental wheel urging means acts to urge the. supplemental wheel into engagement with the abrasive surface. wheel.

7. Means as defined in claim 6, wherein the peripheral surface of the. wheel is also yieldable radially of said wheel.

8. Means as defined in claim 7, wherein the Wheel surface is cylindrical.

9. The combination of an abrasive carrier having a continuous abrasive material carrying surface comprising a closed circuit perimeter, abrasive particles in tension resisting connection with saidsurface, means to sup port said carrier for travel of its surface in said closed circuit perimeter of travel, said closed circuit perimeter of travel including a work body abrading location, together with means to continuously remove detritus material from the abrasive carrying surface of said carrier, comprising a Wheel adjacent to said carrier, said wheel being provided with a yieldable resilient elastic peripheral surface, and means to journal said wheel with its peripheral surface in running engagement with the abrasive surface of the carrier.

10. Means as defined in claim 9, wherein said wheel is journalled with its peripheral surface in compressive pressure with the abrasive surface of the carrier.

11. Means as defined in claim 10, together with means to vary the amount of the compressive pressure of the peripheral surface of the wheel against the abrasive surface of the carrier.

12. Means as defined in claim 9, together with means to supply wetting agent to the location of running engagement of the peripheral surface of the wheel with the abrasive surface of the carrier.

References Cited in the file of this patent UNITED STATES PATENTS