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Title:
HOOKING DEVICE FOR WORKING TOOLS
Document Type and Number:
WIPO Patent Application WO/2020/084379
Kind Code:
A1
Abstract:
A hooking device (10) for working tools for flat glass sheets or flat crystal glass sheets, mirror glass sheets, or also flat marble, granite and similar stone material slabs, comprised of a first component and of a second component that can be coupled to one another and separated from one another, and formed, respectively, by a plate (12) to be fastened to a spindle, which controls the turning operation of a grinding tool, and by a backing pad (14) coupled to the plate (12) and comprised of a grinding wheel (13) on the opposite side to the coupling to the plate (12); furthermore, such device is comprised of first and second coupling devices for quick coupling, formed respectively on the above-said plate (12) and backing pad (14) and cooperating with one another to form a tight and anti-rotational coupling.

Inventors:
BOVONE VITTORIO (IT)
Application Number:
PCT/IB2019/058727
Publication Date:
April 30, 2020
Filing Date:
October 14, 2019
Export Citation:
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Assignee:
BOVONE DIAMOND TOOLS S R L (IT)
International Classes:
B24B45/00; B24D7/06
Domestic Patent References:
WO2001096067A12001-12-20
Foreign References:
US4907376A1990-03-13
EP2915630A12015-09-09
EP2524766A22012-11-21
Attorney, Agent or Firm:
MANFREDI, Irene et al. (IT)
Download PDF:
Claims:
CLAIMS

1. A hooking device (10) for working tools for flat glass sheets or flat crystal glass sheets, mirror glass sheets, or also flat marble, granite and similar stone material slabs, comprised of a first component and of a second component that can be coupled to one another and separated from one another, and formed, respectively, by a plate (12) comprised of an essentially disc-shaped body (15) that has a through-hole (16) in the middle, providing a slot in which a rotating shaft of a spindle engages, to which such plate (12) is securely fastened and which controls the turning operation of a grinding tool, and by a backing pad (14) comprising of a disc-shaped element coupled to the plate (12) coaxially and comprised of a grinding wheel (13) on the opposite side to the coupling to the plate (12); furthermore, such device is characterised by the fact that the plate (12) is comprised of two or more teeth (22) radially developing and that the backing pad (14) is comprised of two or more shaped attachments (40) to engage with the two or more teeth (22) for a quick and tight coupling with rotation of such backing pad (14) in an axial coupling direction in relation to the plate (12); furthermore, such plate (12) comprises secure and anti rotation devices in relation to the backing pad (14) .

2. The device according to claim 1, characterised by the fact that the two or more teeth (22) radially developing are formed in a middle pocket (20) of the plate (12) opposite to the first front (15' ) of the body (15) towards the spindle .

3. The device according to claim 2, characterised by the fact that the two or more teeth (22) are formed from an inner edge of the circumference of a ring-shaped attachment (18) developed from an outer edge of a second flat front (15' ' ) of the body (15) opposite to the first flat front (15') and perpendicularly to that second flat front opposite to the first flat front (15'); such teeth (22) develop radially towards the hole (16) and partially develop towards the above-said second flat front (15''), thus forming a recess (21) between the above-said teeth (22) and the above-said second flat front (15'') .

4. The device according to claim 3, characterised by the fact that, at the point where the recess (21) of at least one of such teeth (22) is positioned, a pair of essentially adjacent radial holes (24) passing through the ring-shaped attachment (18) is formed; such holes (24) provide a slot for anti-rotation devices, including a pin (26) .

5. The device according to claim 1, characterised by the fact that the backing pad (14) is comprised of a first disc-shaped part (30) comprising a first front (30'), on which a pocket (32) is formed, from the outer edge of such first disc-shaped part (30) towards the centre, a pocket

(32) circular-crown shape aimed at forming a slot to engage a ring-shaped grinding wheel (13), and an additional pocket

(33), also formed on that first front of the first circular part (30), centrally thereto and coaxially with the pocket (32), such additional pocket (33) will feature a number of bent fins (34) perpendicularly to the plane of the above- mentioned first front (30') .

6. The device according to claim 5, characterised by the fact that a tubular attachment (36) develops from a second front (30'') of the disc-shaped part (30) of the backing pad (14), opposite to the first front (30'), a number of ribs (38) are formed on its outer side surface (36'), which protrude outwards from such side surface, and which are circumferentially arranged along the tubular attachment (36) at an equal distance from one another and with the two or more shaped attachments (40) formed outwards the tubular attachment (36) and the ribs (38), developing perpendicularly to the above-said second front (30'') and departing therefrom.

7. The device according to claim 6, characterised by the fact that each shaped attachment (40) is essentially "T" shaped and feature a main body (40') developing as a bent surface, whose bending corresponds to that of the tubular attachment (36), and two opposite arms (40'') that develop with the same bending as the main body (40')/ departing from one another and starting from the opposite side edges of the main body (40') at one end of the above-said main body opposite to the second front of the disc-shaped body (30) .

8. The device according to claim 7, characterised by the fact that the shaped attachments (40) develop as a conical surface, the axis of which corresponds to the vertical axis of the backing pad (14), and tapering off in a direction opposite to the first front (30') of the disc-shaped body (30) .

9. The device according to one or more of the above claims, characterised by the fact that the backing pad (14) is preferably made of a resin reinforced with glass powder.

10. The device according to one or more of the above claims, characterised by the fact that the backing pad (14) is first fitted onto/coupled to the plate (12) coaxially and the tubular attachment (36) engages in the pocket (20) of the plate (12), and the two or more shaped attachments (40) are arranged in the space between two teeth (22) of that plate (12), and then, following_a manual rotation on a vertical "y" axis, which corresponds to the motor rotation axis, the arms (40'') of the shaped attachment (40) of the backing pad (14) engage in the recess (21) of the plate (12), the rotation of such backing pad (14) in relation to the plate (12) continues until the shaped attachment (40) of that backing pad (14) is no longer positioned so that a side edge of that main body (40') is in line with the tooth (22) of the plate (12), and the secure and anti-rotation locking of the backing pad (14) in relation to the plate (12), as coupled, is achieved by hooking a pin (26) into a hole (24) of the plate 12) .

Description:
HOOKING DEVICE FOR WORKING TOOLS

This invention refers to a hooking device for working tools for flat sheets.

Namely, this invention refers to a hooking device for working tools for flat glass sheets or flat crystal glass sheets, mirror glass sheets, or also flat marble, granite and similar stone material slabs, in order to use such tools to work along the edges of flat sheets to carry out grinding, edging, bevelling (that is, a process aimed at creating a typically less than 90-degree bevel along an edge) and similar works along the edges of the above-said flat sheets.

As already mentioned, this invention refers to flat sheets and preferably, but not limited to, flat glass sheets, a material that is widely used in a number of fields, for many and varied purposes.

Among the various types of glass, so-called flat glass is used in both civil and industrial applications for glass walls, fagade cladding, decorations and floors, as well as to manufacture furnishings and the like.

Furthermore, flat glass can be single-layer or multi-layer glass, when it is formed by overlapping two or more flat glass sheets, sometimes interposed by polyvinyl-butyral or PVB films, or films of other known engineering plastics used to manufacture shatter-proof or bullet-proof glasses or the like.

Typically, flat glass sheets undergo a surface treatment called 'grinding' , in order to remove the sharp and irregular edge of the glass sheet itself. Such grinding involves the removal of material, which is performed either manually or automatically, and allows 'polishing' and evening out the edge of the sheet, and also shaping it according to given requirements of use and/or appearance (for instance, bevelling is aimed at creating a 'bevel' , which also serves an aesthetic purpose) .

The above-mentioned works are performed using so-called grinding wheels, which are installed on grinding machines that move the sheets in a straight line, and such grinding machines can perform the above-said works along the edges with the flat sheets placed in either a vertical or horizontal position (the latter are known as 'bilateral' grinding machines) .

Such grinding wheels are typically metal and resin-bonded diamond wheels, comprised of a 'cup' element (forming the wheel body) of variable diameter (usually a diameter of 150mm) , and an abrasive part to grind the sheet, placed along the perimeter edge of the cup element. Furthermore, the cup element has a hole in the bottom (on the opposite side to the abrasive part), which is aimed at providing a coupling element to a spindle motor shaft, onto which the wheel is fitted using a bolt and a lock nut, or another known retaining system.

The cup element that forms the wheel body can be made of metal (e.g. aluminium, weighing around one kilogram) or resin (weighing around 650 grams) .

Once it is worn out, the abrasive part of the wheel must be replaced with a new one to ensure the quality of the work; typically, the replacement requires two operators and approx. 15 minutes; this represents a drawback in terms of increase in production costs, given that the use of labour force, as well as significant working time and machine downtime, is required.

Furthermore, in traditional wheels, once the abrasive part is worn and old, the whole grinding wheel (abrasive element and cup) can no longer be reused, and it must be disposed of as special waste, which is another disadvantage in terms of costs.

In addition and in relation to the above-said issues, traditional wheels pose another disadvantage, which arises from the fact that their design requires different types of wheels to be kept in stock depending on the type of grinding/edging/bevelling machine one intends to use.

A traditional coupling for grinding tools, which poses the above-said disadvantages, is described in US4907376, which refers to a plate to be attached to a spindle and a grinding tool fitted onto that plate by way of a threaded connection that contains nuts and bolts.

Other known solutions for the above-mentioned coupling issues are described in EP2915630 and EP2524766, where the grinding tool is fitted onto the plate, which is locked onto the spindle by magnetic attraction.

Another type of connection is described in W001/96067, where the grinding tool is fitted onto a plate, which in turn is attached to the spindle by way of manually operated elastic means, and namely the plate is comprised of elastic-operated pins, which engage in slots on the grinding tool by manual compression.

The purpose of this invention is to avoid the above- mentioned drawbacks.

More specifically, the purpose of this invention is to provide a hooking device for working tools for flat sheets that allows simplifying tool replacement operations in the event of wear/tear/breakage, or the like, affecting the abrasive part of the grinding wheel.

An additional purpose of this invention is to provide a hooking device that does not require to keep many different types of wheels in stock, depending on the types of machines they are intended for.

An additional purpose of this invention is to provide users with a hooking device for working tools for flat sheets that ensures long service life and resistance over time, as well as being easily and cost-effectively replaced.

These and other purposes are achieved by the invention, whose features are presented in claim 1. According to the invention, a hooking device is provided for working tools for flat glass sheets or flat crystal glass sheets, mirror glass sheets, or also flat marble, granite and similar stone material slabs, comprised of a first component and of a second component that can be coupled to one another and separated from one another, and formed, respectively, by a plate to be fastened to a spindle, which controls the turning operation of a grinding tool, and by a backing pad coupled to the plate and comprised of a grinding wheel on the opposite side to the coupling to the plate, first and second coupling devices for quick coupling, formed respectively on the above-said plate and backing pad and cooperating with one another to form a tight and anti-rotational coupling.

Convenient embodiments of the invention are detailed in dependent claims .

The design and functional features of the hooking device for working tools for flat sheets according to this invention will be better understood thanks to the detailed description below, which refers to the drawings attached hereto, which represent its preferred and non-limiting embodiment, and where:

Figure 1 is an axonometric view of a first component of the hooking device for working tools for flat sheets according to this invention;

Figure 2 is a partially sectioned axonometric view of the above-said first component;

Figure 3 is an axonometric view of a second component of the invention device;

Figure 4 is an additional axonometric view of the second component referred to in figure 3;

Figures 5 and 6 are an axonometric and a partially exploded section view of two steps in a coupling sequence of the above-said first and second components of the invention device . As far as the above-mentioned figures are concerned, the hooking device for working tools for flat sheets according to this invention, globally identified by number 10 in the figures, is comprised of a first component and of a second component that can be coupled to one another and separated from one another (as better described below) , and formed, respectively, by a plate 12 to be fastened to the motor, which controls the turning operation of the grinding tool, and by a backing pad 14 coupled to the plate 12 and comprised of a typically ring-shaped grinding wheel 13 (marked by a dotted line in figures 3 and 4) on the opposite side to the coupling to the plate 12.

The plate 12, which is the first element of the invention device, is comprised of an essentially disc-shaped body 15 that has a through-hole 16 in the middle, providing a slot in which a rotating shaft of a spindle engages, to which such plate is securely fastened (by means of a bolt and a lock nut, or other known retaining systems), a first flat front 15' to come into contact with the spindle, and a ring-shaped attachment 18, which, from a second flat front 15'' opposite to the first front 15' of the disc-shaped body 15, develops circumferentially on the outer edge of that second front 15'' and perpendicularly to the plane of the body 15, thus forming, together with the second flat front 15'', a middle pocket 20, the function of which will be clarified later on.

The ring-shaped attachment 18 is comprised of two or more teeth 22 radially developing from an inner edge of the circumference of that ring-shaped attachment 18 towards the hole 16 in the disc-shaped body 15. Such two or more teeth 22, starting from an upper edge of the ring-shaped attachment 18 (opposite to the second flat front 15''), partially develop towards the second flat front 15'', thus forming a recess 21 between the above-said teeth 22 and the above-said second flat front 15'' . In its preferred embodiment, as per the figures, there are four teeth 22 diametrically opposed to each other and arranged in two 90-degree pairs (however, there can also be three teeth, arranged for instance at 120 degrees, or even more than four teeth) .

At the point where at least one of such teeth 22 is positioned, and namely, as far as the embodiment in the figures is concerned, at the point where the recess 21 is positioned, a pair of essentially adjacent radial holes 24 passing through the ring-shaped attachment 18 is formed; such holes 24, as better detailed below, will accommodate a pin 26 that serves as an anti-rotation device.

The plate 12 is made of metal, preferably aluminium or other material suitable for the purpose.

The backing pad 14 is the element to which the diamond grinding wheel 13, with which the edge of the sheet to be processed will come into contact, is associated; as far as its embodiment in figures 3 and 4 is concerned, it is formed by a disc-shaped element that is comprised of a first disc-shaped part 30 comprising a first front 30', on which a pocket 32 is formed, from the outer edge of such first disc-shaped part towards the centre. The pocket 32 circular-crown shape is aimed at forming a slot to engage a ring-shaped grinding wheel 13 (typically, a metal and resin-bonded diamond wheel) , and an additional pocket 33, also formed on that first front 30' of the first circular part 30, centrally thereto and coaxially with the pocket 32; such additional pocket 33 will feature a number of bent fins 34 perpendicularly to the plane of the above-mentioned front .

A tubular attachment 36 develops from a second front 30'' of the disc-shaped part 30, opposite to the above-said first front 30'; a number of ribs 38 are formed on its outer side surface 36', which protrude outwards from such side surface, and which are circumferentially arranged along the tubular attachment 36 at an equal distance from one another; these ribs 38 are aimed at preventing water and/or other processing liquids from entering the plate 12 attached to the spindle, and namely such ribs optimise the distribution of water or other processing liquid, by spraying it on the contact point of the grinding wheel 13 with the glass being processed.

Two or more essentially "T"-shaped attachments 40 develop from the second front 30'' of the disc-shaped part 30 outwards the tubular attachment 36 and the ribs 38, essentially perpendicularly to the above-said second front plane and departing therefrom; such "T"-shaped attachments 40 feature a main body 40' developing as a bent surface, whose bending corresponds to that of the tubular attachment 36, and two opposite arms 40'' that develop with the same bending, departing from one another and starting from the opposite side edges of the main body 40' at one end of the above-said main body opposite to the second front of the disc-shaped body 30; such opposite arms 40'' form coupling elements with the teeth 22 of the plate 12, in the modes detailed below.

The shaped attachments 40 develop as a conical surface, the axis of which corresponds to the vertical axis of the backing pad 14 (which corresponds to the spindle rotation axis) .

Given that grinding wheels to remove/process sheet material operate at a speed between 2800 and 3500 RPM (Round per Minute) , and also given that the grinding wheel must not distort during processing, the above-said backing pad 14 is preferably made of a special resin (e.g. of Polyamide 6.6 type) reinforced with glass powder.

The operation of the hooking device for working tools for flat sheets according to this invention, whose design is detailed above, is described below.

Figure 5 represents the plate 12 and the backing pad 14 before coupling - namely, the plate 12 is attached to the spindle of the grinding machine (as described above) and the backing pad 14 supports the grinding wheel 13 (not represented in the figures) .

Figure 6 illustrates the coupling of the backing pad 14 and the plate 12: the backing pad 14 is first fitted onto/coupled to the tubular attachment 36 in the pocket 20 of the plate 12 coaxially, and the two or more shaped attachments 40 are arranged in the space between two teeth 22 of that plate 12, and then, following a manual rotation (indicated by the "x" arrow in figure 6, either leftwards or rightwards) on a "y" axis (which corresponds to the motor rotation axis), the arms 40' of the shaped attachment 40 of the backing pad 14 engage in the recess 21 between such teeth 22 and the upper front 15' of the plate 12, and the rotation of such backing pad 14 (either leftwards or rightwards) in relation to the plate 12 continues until the shaped attachment 40 of that backing pad is no longer positioned so that its main body 40' (and, more specifically, the side edge of that main body) is in line with the tooth 22 of the plate 12, and in that position, the pin 26 in the holes 24 of the plate 12 securely locks the backing pad 14 in relation to the plate 12 and prevents any rotation of the backing pad itself in relation to the plate and due to the rotation of the spindle motor.

The above is linked to the fact that the rotation to couple the backing pad 14 to the plate 12, which can be either leftwards or rightwards, could be in the same rotating direction as the motor of the spindle to which the plate 12 is fastened; as a consequence, the rotation of the spindle and of the plate 12 attached thereto could cause the backing pad 14, coupled with a movement in the same direction as the motor rotation, to detach or 'unscrew' ; the use of pins 26 prevents this situation. As pointed out above, the advantages that the hooking device for working tools for flat sheets according to this invention imply are self-evident.

Thanks to its quick coupling/hooking system, as described above, the hooking device for working tools for flat sheets according to this invention conveniently allows simplifying tool replacement operations in the event of wear/tear/breakage, or the like, affecting the abrasive part of the grinding wheel. Indeed, a single operator would be able to easily align and rotate the device to couple the two elements of the plate and the backing pad (which supports the grinding wheel) to the plate that is always fixed in relation to the spindle.

Another advantage is that the invention device does not require keeping in stock a variety of types of different grinding tools depending on the different types of machines for which they are intended, given that the plate to which the grinding wheel (fastened to the backing pad) is coupled always remains attached to the spindle, and therefore the only part to replace is the backing pad.

Another advantage is that the development as a conical surface of the shaped attachments of the backing pad, which form the coupling elements with the plate, and the presence of ribs on the backing pad itself allow ensuring the grip between the backing pad and the plate and optimising the distribution of water or other processing liquid, by spraying it on the contact point of the grinding wheel with the glass being processed. This is unlike what happens with regular 'screw' attachments, which do not prevent grinding swarf from entering the screw itself and, furthermore, cannot ensure the best grip, especially in the event of very fine processing with decimal increments.

Another advantage of the invention device is the fact that the operator coupling the backing pad that supports the wheel to the plate can overlook the rotation direction of the spindle to which the plate is attached; as a matter of fact, the pin 26 locks the backing pad rotation in relation to the plate, regardless of the fact that the backing pad was assembled leftwards or rightwards.

Although the invention is described above with special reference to an embodiment thereof provided as an unbinding and non-limiting example, a technician specialising in the field will be able to identify a number of feasible changes and variations in the light of the above description. As a consequence, this invention intends to encompass all changes and variations that fall within the scope of the following claims .