AU594193B2

AU594193B2 - Sanding or polishing disc

Info

Publication number: AU594193B2
Application number: AU78492/87A
Authority: AU
Inventors: Robert Wolff
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-09-17
Filing date: 1987-09-16
Publication date: 1990-03-01
Anticipated expiration: 2007-09-16
Also published as: DE3705217C1; JP2535033B2; NO162897C; EP0260422B1; ES2021310B3; FI84443C; NO873883L; NO873883D0; DK486287D0; FI874054A; DK486287A; NO162897B; AU7849287A; FI874054A0; EP0260422A3; JPS63134169A; EP0260422A2; FI84443B

Description

111~ 594193

AUSTRALIA

PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority: Related Art: This document contaiins the amendments made under Section 49 and is correct for printing.

TO BE COMPLETED BY APPLICANT Name of Applicant: 0 9 ,**:.*Address of Applicant: "Actual Inventor: Address for Service: nc." ROBERT WOLFF Im Kiesacker 12, 5446 Engeln B. R. Germany ROBERT WOLFF ARTHUR S. CAVE CO.

Patent Trade Mark Attorneys Level Barrack Street SYDNEY N.S.W. 2000

AUSTRALIA

4 Complete Specification for the invention entitled SANDING OR POLISHING DISC.

The following statement is a full description of this invention including the best method of performing it known to me:- 1 So S e

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*00141 Sanding or polishing dish The invention relates to a sanding or polishing dish with a rigid clamping shank which is connected via an elastic coupling to a platelike dish, the deflection of which can le set by a sleeve which can be axially adjusted from the clamping side.

In a known sanding dish of this type (Brasch catalogue, 1976/77, order number: 33938) the coupling consists of a spherical joint part which is attached at the lower end of the clamping shank and, deflectable on all sides, is accommodated by a mounting receptacle provided on the platelike dish, with the joint part being provided with protruding radial extensions, engaging into widened recesses of the mounting receptacle, in order to ensure that it rotates along with the latter. Displaceably arranged on the clamping shank is a sleeve in the form of a cylindrical bush which is stepped in diameter, which can be pushed against the force of a restoring spring, until it engages positively, into the upper, cylindrical opening of a rear jacket fixed on the platelike dish and can be locked in this position by a bayonnetlike catch.

25 When the sleeve engages, the platelike dish is rigidly fixed on the clamping shank so that edge sanding, for example, can be carried out with the sanding dish. When the sleeve is uncoupled, the platelike dish can be deflected on all sides, which is desirable, for example, when surface sanding. However, the known sanding dish only has a limited .deflecting capacity and can be set only in the two extreme positions "rigid" and "flexible".

In addition, this coupling, which is like a ball-andsocket coupling, is expensive to manufacture, Moreover, German Offenlegungsschrifto 3,038,850 discloses a sanding dish in which the clamping shank consists of a flexible shaft which, at its lower end, directly supports a platelike dish which is deflectable Son all sides while the shaft bends. The platelike dish

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Sit assarl -2 can here be set rigid by pushing a sleeve over the flexible clampin, shank and fixing it on a rear threaded stem of the platelike dish. At the other end, the sleeve is clamped directly in the drill chuck of a drive machine and then represents a rigid clamping shank.

However, such flexible shafts are at considerable risk of breaking, at least when a greater deflecting capacity of the flexible shaft is provided. In addition, a sleeve used only when required is awkward to handle, apart from the risk of the sleeve being lost.

German Offenlegungsschrift 3,222,858 discloses a sanding dish in which an intermediate section of the clambing shank directly supporting the platelike dish is designed as a flexible shaft piece, adjoining which on both sides are shank seTrtons which are provided with an external thread. Guided on one of the threaded sections is a union nut which, for bridging the flexible shaft piece, can be turned forward until it also engages into the second threaded section of the clamping shank. In this embodiment, too, the flexible shaft piece represents a component which is at considerable risk of breaking.

Moreove German Offenlegungsschrift 3,301,210 discloses a flexible sanding dish in which the platelike dish supports a rigid, rear sleeve which encloses the 25 clamping shank and in which an elastic coupling is provided in the form of an elastomeric cushion vulcanised on the one hand onto the clamping shank and on the other hand onto the sleeve. However, such an elastomeric cushion, at least when a greater deflecting capacity is 30 provided, is to a considerable extent at risk of breaking.

A means of bridging this elastomeric cushion and thus of setting the platelike dish rigid is not provided here.

Moreover, US Patent Specification 2,629,990 disclose's a fLexible sanding dish in which the elastic 35 coupling consists of an elastomeric cushion vulcanised on the one hand onto the clamping shank and on the other hand onto rear projections of the platelike dish. On its peripheral surface, the elastomeric cushion is edged by a rigid cap which reinforces the cushion as an outer band.

i i i r i i I ai1 C c r r b:; 1:3 ~I i -3 Allocated to the sanding dish are here several caps of different height which are used accor'ding to the degree of stiffening desired. The vulcanised-on cushion here ,is also at considerable risk of wearing or breaking, and the use of interchangeable band sleeves leads to awkward handling.

German Patent Specification 3,439,230, Figs. 1 and 2, discloses a flexible sanding dish in which an elastomeric cushion is likewise vulcanised on the one hand onto an end flange of the clamping shank and on the other hand onto the rear side of the platelike dish. To secure the dish in position, a cap enclosing the cushion is used 'here if required, which cap, at its lower end, has a thread with which it is screwed onto a rear threaded extension of the platelike dish. Here, too, the vulcanised-on cushion again represents an expensive component, and handling the reinforcing cap, to be used only if required, is awkward. Moreover, in Figs. 3 and 4, a sanding dish is revealed here in which the platelike dish 20 has a rigidly attached sleeve which protrudes rearwards and encloses the clamping shank. Provided as an elastic coupling is a cylindrical elastomeric cushion vulcanised on the one hand onto the clamping shank and on the other hand onto the sleeve. Provided as a bridging member for 25 the elastic coupling is a nut which is guided on a threaded section of the clamping shank and is tightened against the rear end face of the sleeve. In this embodiment, the jacket of the elastomeric cushion, during deflection, is constantly compressed between the clamping shank and the sleeve, for which reason an elastomeric cushion which can be highly stressed and is accordingly expensive is required here.

The object of the invention, in a generic sanding or polishing dish, is to provide a very flexible deflecting capacity of the platelike dish, whi.ch deflecting capacity can be set across a wide angular range, the intention being for the sanding or polishing dish, and at the same time especially its elastic coupling, to be distinguished by a wear-resistant construction of'simple a t t

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This object is achieved according to the invention, which provides a sanding or polishing disc comprising: a drive shaft; a sleeve on the shaft having a longitudinally tapered surface at a first end thereof; a flexible member attached transversely to one end of the shaft; a plate-like dish having an annular bead on one side and a sanding or polishing material attached to the other side; a rigid tubular member disposed around the shaft adjacent said one end, wherein: the flexible member is sandwiched between the one side of the plate like dish and one end of the tubular member, the other end of the tubular member having a tapered coupling surface corresponding to the tapered surface on the sleeve, whereby the sleeve limits axial deflection of the tubular member.

A number of advantages are achieved by the invention. By the use of a relatively large flexible member (hereinafter referred to as a joint plate) as an elastic coupling, a very high flexibility is achieved for the deflection of the plate like dish, with the joint plate essentially only being subjected to bending stress during deflection so that the risk of material fatigue is prevented to the greatest possible extent. The deflection angle of the platelike dish can now be 4 i -i

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set within a wide range depending on how far the tapered or conical coupling surfaces are advanced towards one another.

When the coupling surfaces are in full contact, the elastic coupling is rigidly bridged. Moreover, it is of further advantage that the sanding or polishing dish is constructed only of simply individual parts which are merely to be screwed together, so that it can be manufactured inexpensively.

As a result of the invention, the joint plate can be made of spring steel, rubber or plastics. When a rubber or plastic plate is used which can still be compressed to a certain extent, the particular advantage also results that, even when the coupling is bridged, a slight residual flexibility remains t for the platelike dish, as a result of which the smooth running 4 95 is improved even during edge sanding.

According to further features of the invention, the joint plate can be reduced to a cross shape which can consist of two crossing strip pieces of spring steel or plastics.

Other features and possibilities of embodying the subject- S V matter of the invention are stated in the subclaims and are S described in greater detail below with reference Si Ii I 4ai: 0193k/AT iw'j"* i r c 5 to several exemplary embodiments shown in the drawing, in which: 7 Fig. 1 shows 'invention in Fig. 2, Fig. 2 shows according to Fig. 3 shows or polishing Fig. 4 shows arrow IV, of according to Fig. 5 shows vided on the Fig. 6 shows a sanding or polishing dish according to the a vertical section along section line I-I in a plan view of the sanding or polishing dish Fig. 1, a second exemplary embodiment of a sanding dish in vertical section, a plan view, viewed in the direction of the adjustable sleeve in the embodiment Fig. 3, a developed view of the notched seats prosleeve according to Fig. 4, a plan view of an alternative embodiment of 0l ii wr-e

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i _I tQ1 1 44( 4 44(4 4r 4 4 I 44 4 i 4/ 4*r 44 *e C 14*0( 4/ 4 the joint plate of the sanding dish according to the invention, and Figs. 7, 8 and 9 show three further exemplary embodiments for the design of the adjustable sleeve.

The sanding or polishing dish according to Figs.

1 and 2 has a rigid clamping shank 1, on the lower front end of which a joint plate 2 in the form of a flat rubber or plastic plate 3 is firmly clamped by means of a screw 4 which has a head. At the same time, the plate 3 is held between two dish springs 5, 5, the diameter of which, decisive for clamping the plate, i.e. the diameter of the contact area of the dish springs on the rubber plate, is about one-third of the plate diameter.

The outer edge area of the plate 3 is firmly 30 clamped between a raised annular bead 6 of a platelike dish 7 and the base 8 of a hood-shaped flange 9 by means of four screws (not shown) distributed over the periphery.

The diameter of the plate 3 is approximately equal to half the diameter of the platelike dish 7. The flange 35 9 is drawn in roof-shaped at the top and has a conical opening 10 which encloses the clamping shank 1 with considerable clearance so that the platelike dish 7, while the plate 3 deflects, is tiltable on all sides relative to the axis of the clamping shank 1.

iiI; '4 vi p i i 6 Displaceably guided on a thread 11 of the clamping shank 1 is a sleeve 12, the lower end of which is made as a taper 13, the slope of which is adapted to the conicity of the opening 10 so that a corresponding mating coupling surface 14 on the sleeve 12 is allocated to the tapered coupling surface 15 of the flange 9. In the position shown in Fig. 1, the taper 13 lies axially above the conical opening 10 so that the platelike dish is maximally deflectable until the flange 9 abuts against the shank 1. When the taper 13 is partly screwed into the opening 10, the deflecting capaci y of the platelike dish 7 is restricted to a smaller angle, in which case the setting of the deflecting capacity can be varied continuously. If the taper 13 is screwed in until coupling is complete, the flange 9 is rigidly secured in position on the clamping shank 1 so that the plate 3 can no longer be bent out. However, the platelike dish 7 can still be deflected to a slight extent provided by the axial compressibility of the plate 3 in its outer clamping area.

S As is also apparent from Fig. 1, the screw 4, with t its head 16 of hemispherical configuration, rests as a 120, pivot bearing on the central area of the platelike dish i 7 and thus improves the smooth running of the platelike S* 25 dish. The platelike dish 7 supports a rubber layer 17 4 Ch t C and an adhesive plate 18 for a sanding or polishing disc.

Moreover, the flange 9 supports a bush 9a which protrudes Sdownwards, encloses the shank with clearance and forms a stop for the maximum application of the joint plate C 30 2 when the sleeve 12 is tightened.

MS In the exemplary embodiment according to Figs. 3 to 5, the joint plate 2 consists of a spring-steel plate r 19 which, in the same manner as in the exemplary embodim* ment a&gording to Figs 1 and 2, is firmly clamped in the t a C 35 central area on the clamping shank 1 and is clamped by i means of the screws 45 in the edge area between the platelike dish 7 and the hood-shaped flange 20 under the interposition of elastic plates 44.

SDisplaceably and rotatably mounted on the clamping -7 shank 1 i a sleeve 21 to which a locking device, which is like a bayonnet catch, is allocated. The sleeve 21 is supported via a compression spring 22 on the rear end of the flange 20 having a stop bush 20a and bears at the rear against a transverse pin 23 passing through the clamping shank 1. On its rear side, the sleeve 21 has several notched seats 24, 25, 26 distributed over the periphery and in the form of diametral slots of different depth for selectively locating the transverse pin 23, cf. also Figs. 4 and 5. The notched seat 24 is used for locking the sleeve 21 in the fully uncoupled position according to Fig. 3, the notched seat 25 is used for securing an intermediate position and the notched seat 26 is used for locking the sleeve in its deepest engagement position. Adjustment is effected in each case by pressing down the sleeve 21 against the force of the compression spring 22 and subsequently turning it, with inclined contact ramps 27, 28, 29 for the transverse pin 23 which in each case rise towards the notched seats of S 20 shallower depth being provided between the notched seats 24, 25, 26. The spring 22 can also be omitted, and instead a self-locking seat of the sleeve 21, made, for example, of plastic, can be provided on the shank.

i e Instead of a round spring-steel plate 19, the joint plate shown in Fig. 6 and reduced to a cross shape can also be used which can be made in one piece or as shown in Fig. 6 can consist of two crossing strip pieces 31, 32 of spring steel or plastic.

S"s Instead of the sleeves 12, 21 shown in Figs. 1 and c t c 30 3, the sleeve 33 shown in Fig. 7 can also be used which is displaceable on the clamping shank 1 and can be firmly cc clamped on the clamping shank 1 by means of a locking sc rew 0 34. i Fig. 8 shows a further embodiment of the slee e 35 which here consists of a chuck which is arranged o the i clamping shank 46 and has an allocated adjusting r.it 36.

i *The gripping jaws 37 are orientated towards the clamping end of the shank. The opposite front end of the threaded shank 38 of the chuck is designed as a taper with the, LK K. n

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Claims

3. A sanding or polishing disc according to claim 1 or claim 2, wherein the flexible member is cross-shaped. S 4. A sanding or polishing disc according to claim 3 wherein the cross-shaped flexible member comprises two strips of spring steel or plastics. A sanding or polishing disc as claimed in any one of claims 1 to 4, wherein the sleeve is movable on the shaft.
6. A sanding or polishing disc as claimed in claim 0175k Ui:TiIU wherein the sleeve i's movable by means of complementary shreads on the sleeve and shaft.
7. A sanding or polishing disc as claimed in any one of claims 1 to 5 wherein there is a spring intermediate said sleeve and said tubular member, said shaft has a transversely o Iextending pin and said sleeve has a plurality of longitudinal grooves of different lengths on its inner surface for selectively engaging the pin such that the longitudinal position of the sleeve relative to the shaft may be altered.
8. A sanding or polishing disc as claimed in claim 7, wherein the grooves are joined by inclined ramps, upon which the pin bears when intermediate the grooves, the ramps inclined such that when the pin bears on a ramp, the spring urges the sleeve towards the shortest groove. o 9. A sanding or polishing disc as claimed in claim 7 wherein the sleeve has, at its end opposite the first end, a second Scoupling surface upon which a gripping jaw or jaws may bear. t 10. A sanding or polishing disc as claimed in any one of claim 1 to 4 wherein the sleeve is formed integral with the shaft and is located intermediate the one end of the shaft and e the free end of the tbular member and the coupling surface is movable with respect to the tubular member. Ir 11. A sanding or polishing disc, substantially as herein described with reference to the drawings. DATED this 19th day of September, 1989. ROBERT WOLFF By His Patent Attorneys P L 4 ARTHUR S, CAVE CO. jfW A O i: L 'I