US3667170A - Finishing article and support member therefor - Google Patents

Abstract

A finishing article having a drive member permanently affixed on one side thereof. The drive member comprises a hollow boss open at its outer end and has an annular lip defining an internal screw thread. A support member is provided connectable with the drive member and can include an axial stud having an external screw thread, formed for insertion within the driving member boss, and a central socket disposed radially about the stud and close fit therewith for abutment against the driving member boss.

Description

United States Patent MacKay, Jr. 51 June 6, 1972 [54] FINISHING ARTICLE AND SUPPORT 3,082,582 3/1963 Jeske ..5 1/358 MEMBER THEREFOR 3,149,442 9 1964 MacKay, Jr. et al ..s1/377 3,315,420 4/1967 Moberg ..51/378 [72] Invent 3;? 2,996,851 8/1961 Gianatasio ..5 1/378 [73] Assignee: Norton Company Primary Examiner-Othell M. Simpson [22] Filed: Mar. 11, 1969 Attorney-Nflsson, Robbins, W1lls & Berliner 21 Appl. No.: 806,250 57 ABSTRACT A finishing article having a drive member permanently affixed [52] US. Cl "51/389 on one side thereof, The drive member comprises a hollow [5 1 CL "324d 17/00 boss open at its outer end and has an annular lip defining an [58] Field oiSearch ..5l/358-379,38Q; internal Screw thread A support member is provided com 85/32 v nectable with the drive member and can include an axial stud having an external screw thread, formed for insertion within [56] References end the driving member boss, and a central socket disposed radin- ATES PATENTS ally about the stud and close fit therewith for abutment against the driving member boss. 2,824,480 2/1958 Hotchkin ..85/32 V 3,041,797 7/1962 Moffly .I ..51/378 9 Clainmfi Drawing Figures I 20 I 35 '1'", 1; u 7 I 5 (3-233: 3' "69-1 "-1 ".':':."f:1 "3'2? '11 'JJ'I PATENTEDJUN 6 m2 SHEET 10F 2 JOSEPH H.

PATENTEDJUM s [972 SHEET 2 OF 2 KY m m M H w 5 m BACKGROUND OF THE INVENTION 1. Field of the Invention The field of art to which the invention pertains includes the field of finishing, more particularly with respect to abrasive finishing articles and supporting members therefor.

2. Description of the Prior Art A variety of designs have been developed for the driving means of rotatable finishing articles. Metal and plastic drive members have been provided and have been designed so that the drive member couples with a corresponding component on the support member. Such prior art drive members have presented various problems such as difficulty of attachment, expense of manufacture, lack of reliability during use where high temperature and stress are created, and the like. Examples of such prior art devices are shown in US. Pat. Nos. 3,270,467, 3,340,652, 3,166,877, 3,1 19,208, and 3,149,442.

SUMMARY OF THE INVENTION The present invention provides a finishing article and support member therefor which utilizes a drive member which is both female and male in its functions and yet is of such simple construction as to enable the fabrication of inexpensive driven abrasive finishing articles. In particular, a hollow boss is provided affixed by a flange to the backing of the finishing article and which is shaped exteriorly so as to have an annular peripheral shoulder the highest point of which abuts against the roof of a socket centrally disposed in the supporting member simultaneously with the flange abutting the bottom of the socket; in this aspect, the boss functions as a male component receivable within the socket which functions as a female component.

The hollow boss is open at its outer end and has an annular li thereat, the lip being broken and curved inwardly to define an internal screw thread for the boss. The supporting member is provided with an axial stud, projecting centrally from the aforenoted socket and having an external screw thread for threadedly coupling to the internal screw thread within the boss. In this aspect, the boss functions as a female component receiving the axial stud of the supporting member which stud functions as a male component.

Accordingly, the drive member of the finishing article functions both as a female and as a male component. Furthermore, both these functions are accomplished with a drive member that is structurally strong, yet light, simple and economical of manufacture. The design is sufiiciently simple to readily lend itself to modern economical construction methods. Such a method is described in US. Pat. No. 3,149,442, relating to a joint invention by M.J. McKellar and myself. In another embodiment of this invention I provide a method of construction which is particularly suitable herein. The method comprises providing the underside of the drive member or the top surface of a fabric layer with a coating of plastic material that is initially heat plasticizable and then solidifies but thereafter may thermoset to bond the driving member to the finishing article.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of a support member having an abrasive finishing article attached thereto, constructed in accordance with this invention;

FIG. 2 is a perspective view of a support member and an abrasive finishing article in accordance with the present invention in disassembled position;

FIG. 3 is a cross-sectional, partial view of the drive member and finishing article illustrated in FIG. 2, taken about the lines 3-3 thereof, in the direction of the arrows;

FIG. 4 is a cross-sectional, partial view of the assembled support member and finishing article illustrated in FIG. 1, taken about the lines 44 thereof, in the direction of the arrows;

FIG. 5 is a cross-sectional, partial view of an assembled support member and finishing article in accordance with another embodiment of this invention; and

FIG. 6 is a perspective view of a socket member utilized in the structure depicted in FIG. 5.

DESCRIPTION OFTI-IE PREFERRED EMBODIMENTS Referring to FIG. 1, there is generally disclosed'a finishing device 10 comprising an abrasive finishing article 11 attached to a support member 12 therefor. As is therein illustrated, the finishing article 1 1 is attached by coupling member, not shown in FIG. 1, but which will be more fully described hereinafter, which are integral parts of the finishing article 1 l and support member 12. A spindle or shaft 13 extends from the support member 12 and is adapted to engage a power drive tool (not shown), such as a pneumatic or electric motor, or the like, for purposes of rotating the finishing device 10.

Referring to FIG. 2, components of the support member 12 and finishing article 1 1 are shown in more detail. The finishing article 11 has a layer of finishing material, such as abrasive particles of aluminum oxide adhered to one side 14 of a circular sheet 15 of vulcanized fiber and a smaller disk of cloth constituting a backing member 16 on the other side thereof. A drive member 18 is permanently affixed to the backing member 16, as will hereinafter be described, and comprises an annular flat metal member or flange 20 having a deformed central portion defining a hollow boss 22. The drive member 18 is constructed of a metallic material, such as cold rolled steel and is formed from a disk as by stamping or the like. With additional reference to FIG. 3, the drive member boss 22 is open at its outer end and has a lip 24 curved inwardly to provide an annular peripheral shoulder 26. The lip 24 is broken at 28 and formed so as to define an internal screw thread.

Referring now more particularly to FIG. 3, there is illustrated in cross-section an abrasive finishing article which may be manufactured incorporating a drive member 18 of this invention. It should be understood that the drawing in FIG. 3 is schematic and has been greatly exaggerated for purposes of clarity and ease of illustration. As is therein shown, a sheet of abrasive material of any type which is presently known to the art is provided. Preferably, the abrasive finishing material includes a disk or sheet of vulcanized fiber about 0.030 inches in thickness and has abrasive particles 25, such as aluminum oxide, adhered thereto on one side by a layer 27 of adhesive. If such is desired, and as is well known in the art, the layer 27 of adhesive may have a sand-size layer 29 applied thereto to more adequately and firmly bond the aluminum oxide particles 25 to the fiber sheet 15. On the opposite side of the fiber disk 15, a cloth disk backing member 16, slightly larger than the outer diameter of the drive member 18, is secured to the fiber disk 14 by means of any adhesive which is known to the art and which is adaptable for such purposes. For example, a layer 33 of polyvinyl acetate may be utilized for this purpose.

In order to affix the drive member 18 to the backing of the finishing article 11, the undersurface 35 of the drive member 18 is spray coated with a layer of plastic adhesive. In this regard, the procedure disclosed in US. Pat. No. 3,149,442 may be followed wherein a layer of polyvinylchloride is applied to both the drive member undersurface 35 and the top surface of the backing member 16, heat plasticized and allowed to cool to bond the parts. In a particularly suitable method of bonding, the drive member 18 stamped from a circular disk and its undersurface 35 is then spray coated with a thermoplasticthermosetting adhesive 37. Such a material is initially heat plasticizable, but thermosets on prolonged heating. Other materials, or mixtures, having such properties are known to the art and may be utilized herein. The drive member 18 with the adhesive 37 thereon is then applied to the upper layer of the cloth backing member 16 and heat and pressure is applied. Initially the adhesive coating 37 becomes plastic and as the cycle continues it thermosets to thus create a permanent and nondestructive bond between the metal drive member 18 and the cloth backing member 16. The bond thus obtained has been found to be surprisingly tenacious. Extreme force can be applied to the edge portions of the metal drive member 18 without destroying the bond. Very large amounts of power at very high rotational speeds may be applied to finishing articles of the present invention and they will perform unexpectedly well under such conditions with no signs of fracture or other breakdown. A great advantage of the structure of the present design is its ability to be utilized with the method of bonding discussed hereinabove.

Referring now more specifically to FIG. 4, the details of construction of a particular support member in accordance with the present invention is illustrated. As shown, there is provided a centrally disposed core in the form of a cylinder 30 having a bore 32 therein which opens into a much larger bore 39. A cylindrical stud 36 is press-fitted within the smaller bore 32. The stud 36 is provided at its lower end portion with an external screw thread 40 which is sized and pitched to thread into the internal screw thread defined by the lip 24 of the drive member boss 22. The upper end of the cylindrical stud 36 is provided with a centrally disposed bore 44 which is threaded to receive the threaded end portion 46 of a spindle 48. The spindle 48 is aligned bya threaded member 50. Obviously, the stud 36 and spindle 48 may be formed of a single member.

The threaded end 40 of the stud 36 projects axially through the cylinder and juts into the larger bore 39. A socket 41, having a threaded bore 43 centrally therethrough is threaded into the stud 36 until its top surface 45 is flush with the roof 47 of the large cylinder bore 39. The parts are sized so that the bottom surface 42 of the threaded stud portion 40 is substantially on a plane with the bottom surface 52 of the cylinder 30 and bottom surface 53of the socket 41. A central portion of the bottom of the socket 41 is removed to form a hollow 55 for receiving the driving member boss 22. The hollow 55 is as deep as the height of the boss 22 at its highest point and its roof 57 is sufficiently close fit'to the stud threads 40 to project therefrom and form a blind or metal trap against intrusion through its bore 43 of the driving member boss 22.

In order to construct the support member 12 the cylindrical core member 30 is placed within a mold along with a layer 54 of fabric, such as neoprene-impregnated cloth. The fabric 54 forms the bottom surface of the support member for the abrasive finishing article in accordance with the present invention. The mold is then filled with the particular desired compound such as neoprene to form a body portion 56 as the flexible support component. Upon cooling and removal from the mold, the completed support member for the abrasive finishing article in accordance with the present invention is provided. The mold is shaped so that a central recessed portion 58 is provided in the otherwise flat bottom surface 60 of the Support member. The recessed portion 58 accommodates the flat annular ring constituting the base of the boss 22 when the support member is coupled to the finishing article 1 l. As illustrated in FIG. 4, when the support member 12 is coupled to the finishing article 11, the boss 22 projecting from the backing of the finishing article 11 functions as a female component in receiving the externally threaded end 40 of the support member stud 36. The finishing article is rotated so that the stud 36 is threaded into the boss 22 until the highest point of the peripheral shoulder 26 of the boss 22 abuts the roof 57 of the socket hollow 55. At that point of contact, the boss 22 functions as a male component, seating and bearing with the highest point of its peripheral shoulder 26 against the roof S7 of the socket hollow 55. Simultaneously the top surface of the flat annular ring 20 abuts the bottom surfaces 52 and 53 of the cylinder and socket respectively. The result is an effective and very strong coupling between the support member 12 and finishing article 11 which resists pressures, strains and heat and yet which allows the finishing article to be readily removed by simple reverse rotation. The drive member 18 is of simple, economical construction and is light weight and yet provides a strong, positive locking means. The close fit of the socket 41 to the studs 36 creates a metal trap and prevents the boss 22 from deforming. It has been found the boss is undeformed even when enough force is utilized to tear the backing from the abrasive article.

Referring now to FIG. 5, another embodiment of this invention is illustrated wherein an alternative support member is utilized. In this embodiment, a standard type support pad 62 is utilized, which type of pad is readily and widely available and comprises a sisal body portion as the flexible component support on a central cylindrical core member 64 fonned integral with the body portion. The core member 64 defines an internally threaded central bore 66 therethrough to enable the support member to be threaded onto the projecting stud 68 of a power tool. In typical operation, without the improvement of this invention, the support member is threaded onto a power tool stud until it is seated-against a stop mechanism of any type which may be in the fonn of a shoulder, or the like. An abrasive disk is utilized which has a central opening therethrough and is placed upon the lower surface of the support member and held in place by threading a nut over the end of the power tool stud. The support member has a central concavely formed recess 70 in the bottom surface-72 thereof which may be defined by a metal bearing surface 74. During use'with prior art devices the retaining nut very often contacts and mars the surface of the workpiece. As known to those who utilize such devices, at heavy contact pressures, or at large angles of use, the abrasive disk will often slip with respect to the support pad, rending the central portion of the disk and necessitating its replacement.

In accordance with the present embodiment, a standard type of support pad 62, as described above, can be utilized. However, a socket member 76 is provided to adopt the pad to be utilized with the improved finishing article 11 described above. The socket member 76, which is shown in perspective in FIG. 6, includes a cylindrical top portion 78 that has an internally threaded bore 80, to thread onto the end of the power tool stud 68, and a bottom portion 82 that has a wider socket bore 84 in communication with the top bore '80. When threaded on the power tool stud 68, the stud projects into the bottom socket bore 84. The bottom socket bore 84 is sized so as to be as deep as the height of the boss 22 at its highest point on the finishing article drive member 18 so as to receive the boss 22 therein when the drive member 18 is threaded onto the end of the power tool stud 68. Thus, the depth of the socket bore 84 is substantially the same as the external distance between the base 20 and uppermost point on the shoulder 26 of the driving member 18. The socket member 76 is also provided with a hexagonal flange 86 for utilization thereon of a socket wrench.

In utilization, the standard type of support pad 62 is threaded onto the stud 68 of a power tool 88 until it reaches a mechanical stop in the form of a pair of washers 90. The washers 90 are sized so that the end of the stud 68 lies in substantially the same plane as the bottom surface 72 of the support member 62. A washer 92 or similar material is then placed on the stud 68 within the support member recess 70 to provide spacing as required for the socket member to enable the drive member 18 of the abrasive article 11 to be seated therein with the top surface of the abrasive article 11 flush with the bottom surface 72 of the support member pad. The socket member 82 is threaded onto the stud 68 until seated against the washer 92. An abrasive disk 1 1 as above described with respect to FIG. 3 has its drive member 18 threaded onto the end of the stud 68 until the top surface of the drive member flange 20 seats against the bottom, flanged surface 94 of the socket member 26. At the same time the highest point of the shoulder 26 of the drive member 18 abuts the roof 96 of the socket recess 84. By the foregoing simultaneous seating, the abrasive disk 11 when threaded is directly and firmly seated and cannot move any further irrespective of forces that may be applied. The roof 96 of the socket recess is closely fit to the threaded stud and where a metal drive member is used forms a metal trap" against the driving member boss 22 in the manner described with respect to FIG. 4. importantly,

there is no slippage between the abrasive disk 11 and support member 62 unless the driving member 18 is torn from the abrasive disk.

What is claimed is:

1. A finishing article for rotatable engagement with a sup port member formed for removable connection in close external abutment therewith by means of a core member defining an opening for centrally receiving therethrough an axial threaded stud, comprising:

finishing material on one side thereof; and a drive member having a flange and a hollow boss, said flange permanently affixed on the other side thereof and extending radially outwardly from said boss;

said hollow boss defining a central opening at its outer end and having an annular lip thereat, said lip being formed by being curved inwardly to define an internal single screw thread for said axial stud and an annular peripheral shoulder spaced above said lip. 2. The finishing article of claim 1 including a support member connectable therewith, said support member including an axial stud having an external screw thread formed for insertion within said boss and further including a core member defining a surface about said stud for abutment against said shoulder.

3. The finishing article of claim 2 wherein said core member is close fitted to said axial stud so that said abutment surface projects radially therefrom.

4. The finishing article of claim 1 wherein said drive member is metal.

5. The finishing article of claim 4 wherein said metal drive member is afi'rxed with heat plasticizable material.

6. The finishing article of claim 5 wherein said heat plasticizable material is also thermosetting.

7. The finishing article of claim 1 including a support member connectable therewith, said support member including a core member defining a surface for abutment with said drive member and defining an opening for centrally receiving therethrough an axial stud threadable into said drive member, said core member being formed to closely approximate said axial stud so that said abutment surface projects therefrom.

8. A finishing article, comprising:

finishing material on one side;

a drive member having a flange and a hollow boss permanently affixed on the other side thereof;

said hollow boss defining a central opening at its outer end and having an annular lip thereat, said lip being formed to define a single internal screw thread; and a support member connectable with said finishing article, said support member including a core member defining an opening for centrally receiving therethrough an axial stud threadable into said drive member, said core member being formed to closely approximate said axial stud so that said abutment surface projects therefrom;

said drive member including a flanged portion extending radially outwardly from said boss;

said core member having a shoulder portion spaced from said abutment surface to abut said drive member flanged portion.

9. The finishing article of claim 8 wherein the highest point of said boss closely approximates said surface of said core member during the time said flanged portion abuts said shoulder.

Claims (9)

1. A finishing article for rotatable engagement with a support member formed for removable connection in close external abutment therewith by means of a core member defining an opening for centrally receiving therethrough an axial threaded stud, comprising: finishing material on one side thereof; and a drive member having a flange and a hollow boss, said flange permanently affixed on the other side thereof and extending radially outwardly from said boss; said hollow boss defining a central opening at its outer end and having an annular lip thereat, said lip being formed by being curved inwardly to define an internal single screw thread for said axial stud and an annular peripheral shoulder spaced above said lip.

2. The finishing article of claim 1 including a support member connectable therewith, said support member including an axial stud having an external screw thread formed for insertion within said boss and further including a core member defining a surface about said stud for abutment against said shoulder.

3. The finishing article of claim 2 wherein said core member is close fitted to said axial stud so that said abutment surface projects radially therefrom.

4. The finishing article of claim 1 wherein said drive member is metal.

5. The finishing article of claim 4 wherein said metal drive member is affixed with heat plasticizable material.

6. The finishing article of claim 5 wherein said heat plasticizable material is also thermosetting.

7. The finishing article of claim 1 including a support member connectable therewith, said support member including a core member defining a surface for abutment with said drive member and defining an opening for centrally receiving therethrough an axial stud threadable into said drive member, said core member being formed tO closely approximate said axial stud so that said abutment surface projects therefrom.

8. A finishing article, comprising: finishing material on one side; a drive member having a flange and a hollow boss permanently affixed on the other side thereof; said hollow boss defining a central opening at its outer end and having an annular lip thereat, said lip being formed to define a single internal screw thread; and a support member connectable with said finishing article, said support member including a core member defining an opening for centrally receiving therethrough an axial stud threadable into said drive member, said core member being formed to closely approximate said axial stud so that said abutment surface projects therefrom; said drive member including a flanged portion extending radially outwardly from said boss; said core member having a shoulder portion spaced from said abutment surface to abut said drive member flanged portion.

9. The finishing article of claim 8 wherein the highest point of said boss closely approximates said surface of said core member during the time said flanged portion abuts said shoulder.

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