WO2003047812A2

WO2003047812A2 - Connecting device for mechanical members

Info

Publication number: WO2003047812A2
Application number: PCT/IB2002/005077
Authority: WO
Inventors: Alessandro Piana; Cristina Caprioli
Original assignee: Auges S.R.L.
Priority date: 2001-12-05
Filing date: 2002-12-03
Publication date: 2003-06-12
Also published as: ITMI20012563A1; AU2002344394A1; AU2002344394A8; WO2003047812A3

Abstract

A device for the quick connection and separation of at least two mechanical members (1, 2) is described, wherein there are provided with a first connection element (10) and locking means to detachably connect the first connection element (20) to one of the mechanical members. The locking means include at least a second connection element which may be moved between a position abutting against the first connection element and a position disengaged from the first connection element.

Description

"CONNECTING DEVICE FOR MECHANICAL MEMBERS" Field of the invention

The present invention relates to a connection device for two mechanical members which makes it possible to perform particularly quick operations to connect or separate the two mechanical members. Background Art

A device according to the present invention may for example be applied in clamping or fixing systems for workpieces provided to be machined both on fixed supports, such as pallets, and on rotary supports, such as the self-centring chucks of lathes, for fixing the jaws (or clamps) to clamp the workpieces. The device may have other applications, such as the detachable connection of adapters and/or tools in modular tooling systems. The most widely used clamping or fixing systems utilise, for example, T-slots, into which blocks of corresponding shape are inserted and subsequently clamped in position by screws, or threaded pins suitable to be screwed into specific holes distributed in a substantially regular manner on specific supporting plates (pallets). With reference for example to self-centring chucks of the known type, each of the clamping jaws, or each supporting element of these jaws, has a block with a T-shaped section which is inserted into a specific slot made in a corresponding sliding block of the chuck. The surfaces of the jaw and of the sliding block provided to come into mutual contact are generally provided with toothing or a key to allow repeatability of the position of each jaw. The jaw is locked in position by clamping one or more screws.

Nonetheless, when the jaws have to be replaced, it must be borne in mind that the torque wrench setting in known systems is not constant and positioning is difficult.

Considering that each chuck generally has two or more jaws and that each jaw is often locked in place by at least two screws, it is easy to understand that replacement of the jaws of a chuck is particularly time-consuming and may also cause uncertainty as to fixing and positioning.

Moreover, as these operations are particularly frequent if products differing from one another are subjected to machining, the machine idle times may be particularly high. This is also the case in static fixing or clamping systems which employ similar solutions.

For this reason, in some prior art chucks, systems have been designed to facilitate quick replacement of the jaws. Nonetheless, the solutions proposed to date are particularly complicated, costly and above all cannot be employed in chucks already available on the market for which the characteristic of quick replacement of the jaws is not foreseen.

Another possible application of a device according to the present invention is for quick fitting (and quick removal) of tools and/or adapters in modular tooling systems. In many modular tooling systems, for example in "Weldon" type couplings, quick and detachable locking of tools and adapters to basic adaptors of this type is obtained directly by means of grub screws. Nonetheless, the frequent need to fit and remove tools causes wear of the grub screws and, in some cases, rapid deterioration of the tool shank, causing somewhat unreliable locking of said tools through time. Summary of the invention

The task of the present invention is to propose a connection device for two mechanical members which makes it possible to overcome the drawbacks of prior art and which may also be easily adapted to various applications.

Within the scope of this task, an object of the present invention is to produce a device as mentioned above which makes connection of two mechanical members particularly quick and secure.

Another object of the present invention is to produce a connection device as indicated above which is particularly simple to use and requires practically no maintenance.

A further object of the present invention is to produce a connection device of the type mentioned above which guarantees considerable characteristics of connection stability and positioning accuracy.

A particular object of the present invention is to produce a connection device which may advantageously be utilised for quick fixing of the jaws in self-centring chucks already found on the market.

Another particular object of the present invention is to produce a connection device which may also be utilised in static fixing or clamping systems of the parts to be subjected to machining.

Yet another particular object of the present invention is to produce a connection device which may also be utilised in the modular tooling systems of fixed or rotary tool-holders.

These objects are attained by the present invention thanks to a device as specified in claim 1. Further characteristics and alternative embodiments are described in the dependent claims. The invention provides a device for quick connection and separation of at least two mechanical members including at least one first connection element fastenable to a first of the at least two mechanical members. The first connection element is provided with at least one substantially cylindrical portion designed to be inserted into α corresponding cylindrical hole made in the other of the at least two mechanical members.

Locking means are also provided to detachably connect at least the first connection element to the second mechanical member. The locking means in particular include at least a second connection element which may be moved in a substantially transverse direction in relation to the axis of the substantially cylindrical portion of the first connection element. Movement is performed by means of at least one operating member between a position abutting against the substantially cylindrical portion and a position disengaged from said portion.

The second connection element makes it possible to perform numerous types of locking securely utilising a particularly simple operating member, for example a grub screw. The second connection element may in fact include surfaces which are shaped in a manner that makes the locking device applicable in a wide variety of uses.

According to a possible embodiment of the present invention, the second connection element includes at least one surface portion designed to abut in contact against a surface of the first connection element to exert radial thrust on the substantially cylindrical portion of the first connection element. An example of a possible application of this embodiment is the locking of tools and/or adapters to basic adaptors in modular tooling systems. According to another embodiment, the first connection element and the second connection element include cam surface portions designed to mutually abut in contact against each other to exert axial traction on the substantially cylindrical portion of the first connection element. This embodiment may for example be employed to lock the jaws of the self-centring chuck and/or in the locking systems of mechanical workpieces to be subjected to machining.

Notwithstanding the embodiment, the device according to the present invention makes it possible to obtain quick and secure locking of two mechanical members and quick separation of these members. Brief description of the drawings

Further characteristics and advantages of the present invention shall become more apparent from the following description with reference to the attached schematic drawings, in which: - Figure 1 is an exploded perspective view of an embodiment of the device according to the invention for fixing the jaws of a self- centring chuck;

- Figure 2 is a side view of some elements of the device according to a possible embodiment of the present invention; - Figure 3 is a rear elevation view of the first connection element of the device represented in Figure 2;

- Figure 4 is a plan view of the first connection element of the device represented in Figure 2;

- Figure 5 is a perspective view of a first connection element of the device according to another embodiment of the present invention;

- Figure 6 is a section view of an operating means according to a possible embodiment of the present invention;

- Figure 7 is a section view of a second connection element according to a possible embodiment of the present invention; - Figure 8 is a front view of a second connection element according to a possible embodiment of the present invention;

- Figure 9 is a section view of another possible application of the device according to the present invention;

- Figure 10 shows a further possible application of the device according to the present invention;

- Figures 1 1 A-1 1 C are section view of further embodiments of a device according to the present invention; and

- Figures 12A-12C are examples of other possible applications of the device according to the present invention.

Modes for carrying out the invention

Figure 1 schematically represents, purely as an example, the application of a device according to the present invention to a self- centring chuck 1 to allow quick fixing and removal of the jaws 2, one of which is represented for example as comprising a supporting element 2a and a gripping portion 2b. The jaw 2 may in any case also be made as a single piece.

The device according to the present invention includes a first connection element 10 provided with a fixing portion 1 1 and a portion 12 with a substantially cylindrical shape. In the embodiment represented, the fixing portion 1 1 comprises a block with a T-shaped cross section provided to be removably inserted into a slot 3 with a corresponding section. The surfaces 4 of mutual contact between the supporting element 2a of the jaw 2 and the sliding block mounted in the base of the chuck 1 may be provided with toothing as shown in Figure 1.

The substantially cylindrical portion 12 of the first connection element 10 is provided to be inserted into a corresponding cylindrical hole 5 made at least in the supporting element 2a or directly in the jaw 2 in the case in which it is made as a single piece.

The device according to the invention also includes a second connection element 20 which remains housed in a seat 6 of corresponding shape made in the supporting element 2a of the jaw 2.

The second connection element 20 may be moved in a substantially transverse direction in relation to the axis of the substantially cylindrical portion 12 of the first connection element 10 acting from outside on an operating means, consisting in this case of a grub screw 30. An elastic ring 40 may also be provided, housed in a specific slot

46 made in the seat 6, which acts as a lock for the grub screw 30 to prevent it, together with the second connection element 20, from being accidentally removed from the seat 6 during loosening of the grub screw, although allowing removal at the same time should this be necessary.

With reference now to the view in Figure 2, it can be seen that the first connection element 10 and the second connection element 20 include respective cam surface portions 13 and 23 provided to abut mutually in contact against each other. The cam surface portion 13 of the first connection element 10 comprises a flat inclined surface positioned along the side of a transverse groove 14 made in the substantially cylindrical portion 12. The cam surface portion 23 on the second connection element 20 also comprises a flat inclined surface made on the head of the second connection element 20.

When the cam surface 23 of the second connection element 20 is brought into contact with the corresponding cam surface 13 of the first connection element 10, traction is thus exerted in an axial direction (arrow T in Figure 2) on the first connection element 10. In fact, thanks to the inclination of the two surfaces 13 and 23 (for example both inclined by about 30° in relation to a horizontal plane), the force exerted by the grub screw 30 on the second connection element 20 in the transverse direction is multiplied and transformed into an upward thrust in the axial direction. This makes it possible to obtain a noteworthy locking force of the first connection element 10 at the base of the chuck 1.

By loosening the grub screw 30, the second connection element 20 is disengaged from the substantially cylindrical element 12 or, more specifically, the head portion 21 of the second connection element 20 is extracted from the transverse groove 14 thus allowing the jaw 2 to be removed from the portion 12 of the first connection element 10.

The element 10 is provided with a cut 18, better seen in the detailed view in Figure 3, which allows elastic deformation of the fixing portion 1 1 in order to facilitate insertion into and removal from the corresponding slot 3 in the sliding block fitted in the body of the chuck 1 (Figure 1 ) or on any other fitting support provided with an fastening system with T-slot.

In order to limit deformation of the fixing portion 1 1 , a limiting element, such as an elastic pin 50 (Figure 1 ), is preferably inserted into a specific seat 19 made in the fixing portion 1 1.

The top of the substantially cylindrical portion 12 may for example include a rounded end portion to facilitate insertion into the corresponding hole 5 (Figure 1 ) of a jaw or any other locking element provided with a corresponding hole 5.

As better seen in the plan view of Figure 4, the substantially cylindrical portion 12 of the first connection element 10 includes at least two flat reentering surfaces 15 lying on respective secant planes of the cylindrical shape. The planes which form the surfaces 15 are positioned on the opposite side from the groove 14 and intersect at the level of a straight line 16. This solution makes it possible to distribute the points of contact equally between the substantially cylindrical portion 12 and the corresponding hole 5 into which it is inserted, thus recovering the coupling tolerances between these to guarantee high locking stability.

A further flat reentering surface 17 is preferably provided which intersects with the groove 14 to limit the travel of the second connection element 20 inside the groove 14, thus allowing a reduction in the times required to position and remove the jaw from the base of the chuck 1.

Figure 5 shows another possible embodiment of a first connection element 1 10 which includes a substantially cylindrical portion 12 with all the characteristics mentioned hereinbefore, with the sole exception of the fixing portion 1 1 1 , in this case consisting of a threaded pin. The first connection element 1 10 may be employed for example in combination with the fixing platforms of workpieces to be subjected to machining on machine tools or work centres. In this case, in place of the jaws represented in Figure 1 , fixing blocks for the workpieces may also be utilised in which a hole 5, identical to the one shown in Figure 1 , is made.

Figures 6, 7 and 8 show in greater detail some characteristics of the grub screw 30 and the second connection element 20. The grub screw 30 in Figure 6 includes an end 35 appropriately shaped to be inserted into a corresponding seat 25 in the second connection element 20 so as to make them movable together in translation and allow simultaneous rotation of the grub screw 30 in relation to the second connection element 20.

The second connection element 20 shown in Figures 7 and 8 includes in particular a head portion 21 and a pair of arms 22 which extend parallel to the direction of movement of the second connection element 20 in the seat 6. The arms 22 have a semi-circular external profile to guarantee a good contact surface inside the seat 6, in which the thread required to engage the grub screw 30 is also made.

Figure 9 shows another possible application of the device according to the present invention in a locking member 60, with the first connection element 212 which is shown broken in relation to a median line 200 in the two possible positions it can take during operation of the device. Although not specifically represented, an elastic ring 40 may be provided housed in a specific seat 46 (see Figure 1 ) to limit travel of the grub screw 30 and prevent the grub screw 30 and the second connection element 20 from escaping from the corresponding housing seat.

To the left of the line 200, the first connection element 212 is shown in the clamping position, in which the head portion 21 of the second element 20 is engaged in the groove 14, with the respective cam surface portions 23 and 13 mutually engaged. The position represented to the right of the median line 200 is obtained when the head portion 21 of the second element 20 is disengaged from the groove 14. A spring 215, previously compressed, pushes the fixing portion 21 1 outward until the travel is stopped by a pawl 213 which abuts against the head portion 21 of the second connection element 20.

The fixing portion 21 1 is in this case shaped and dimensioned to be in turn connected, together with the block 60, to a system to lock workpieces to be subjected to machining.

Figure 10 shows application of a device according to another embodiment of the invention, with particular reference to modular tooling systems. Similarly to the previous illustration with reference to Figure 9, an elastic ring 40 may be provided housed in a specific seat 46 (not shown in Figure 10, but only in Figure 1 ) to limit the travel of the grub screw 30 and prevent the grub screw 30 and the second connection element 20 from escaping from the housing seat 6.

In this case, the first connection element 310 may comprise a tool or an adapter, with the substantially cylindrical portion 12 constituting the shank of these. The substantially cylindrical portion 12 will thus also have the same characteristics as the portion described with reference to Figures from 1 to 4, that is with a groove 14 and a cam surface portion made on one side of it.

The substantially cylindrical portion 12 is provided to be inserted into a cylindrical hole 305 made in a basic adaptor 301. The seat 6 provided to receive the second connection element 20, provided with the cam surface portion 23, and the grub screw 30 acting as operating means, are also provided on this basic adaptor. The operating principle is identical to the one described previously with reference to the embodiment in Figure 2. Figures 1 1 A and 1 1 B show sections of some alternative embodiments of a second connection element.

The second connection element 120 represented in Figure 1 1A also includes a head portion 121 and a pair of arms 122 which extend parallel to the direction of movement of the second connection element 120 in the seat 6. In relation to the embodiment in Figure 7, the arms 122 also include portions 123 which project inward. This advantageously makes it possible to use a common type of grub screw 130, such as the one shown in the section view of Figure l l C, enclosing the grub screw 130 between the arms 122 and the projecting portions 123. This makes the screw 130 and the second connection element 120 movable together in translation and allow simultaneous rotation of the grub screw 130 in relation to the second connection element 120.

The second connection element 220 represented in Figure 1 1 B includes the same characteristics as the connection element 120 in Figure 1 1 A with regard to the housing of the grub screw 130, and also includes a toothed head portion suitable to be utilised to fix tools or adapters produced according to a specific standard (such as DIN 69880).

Figures 12A-12C show some examples of application of a device according to the present invention to modular tooling systems. In all these embodiments, the second connection element includes at least one front surface portion which is brought into contact with the surface of the first connection element to exert a radial thrust on the substantially cylindrical portion of this. The second connection element is positioned in this case with the head portion substantially perpendicular in relation to the position shown in the embodiment in Figure 10 and includes a head portion shaped to be adapted to the various types of couplings established by the corresponding standards.

For example, Figure 12A shows a connection device of the invention applied to a coupling system shaped according to the standard DIN 1835B, Figure 12B shows a connection device adapted according to the standard DIN 6535HE and Figure 12C shows a connection device adapted according to the standard DIN 6535HB.

Claims

1. Device for the quick connection and separation of at least two mechanical members, of the type including: at least a first connection element fastenable to a first of said at least two mechanical members and provided with at least one substantially cylindrical portion designed to be inserted into a corresponding cylindrical hole made in a second of said at least two mechanical members; and locking means to detachably connect said first connection element to at least said second mechanical member, characterised in that said locking means include at least a second connection element which may be moved along a substantially transverse direction in relation to the axis of said substantially cylindrical portion between a position abutting against said substantially cylindrical portion and a position disengaged from said portion by means of at least one operating member.

2. A device according to claim 1 , wherein said first connection element is removably fastened to said first mechanical member.

3. A device according to claim 1 , wherein said second connection element is housed in a seat with a corresponding section made in said second mechanical member.

4. A device according to claim 3, wherein said second connection element is removably housed in said seat.

5. A device according to claim 1 , wherein said second connection element includes at least one head portion and at least two arms which extend parallel to its direction of movement and perpendicularly in relation to said head portion.

6. A device according to claim 1 , wherein said second connection element includes at least one surface portion designed to abut in contact against a surface of said first connection element to exert a radial thrust on the substantially cylindrical portion of said first connection element.

7. A device according to claim 1 , wherein said first connection element and said second connection element include cam surface portions designed to mutually abut in contact against each other to exert axial traction on the substantially cylindrical portion of said first connection element.

8. A device according to claim 7, wherein the cam surface portion on the substantially cylindrical portion of said first connection element comprises at least a first flat inclined surface positioned along the side of a transverse groove made in said substantially cylindrical form.

9. A device according to claim 1 , wherein said substantially cylindrical portion includes one or more flat reentering surfaces lying on one or more corresponding secant planes of the substantially cylindrical form.

10. A device according to claim 9, wherein said substantially cylindrical portion includes at least two of said reentering surfaces lying on at least two planes which intersect at the level of a straight line.

11. A device according to any of claims 7 to 10, wherein said at least one or more flat reentering surfaces are positioned substantially opposite said cam surface portion in the substantially cylindrical portion of said first connection element.

12. A device according to any of claims 7 to 1 1 , wherein it is provided a flat reentering surface which intersects said transverse groove in said substantially cylindrical portion.

13. A device according to claim 1 , wherein said operating member comprises α grub screw movable in translation with said second connection element and rotatable in relation to the latter, said grub screw being engaged in a thread made inside the seat in which said second connection element is housed.

14. A device according to claim 13, wherein it is provided at least one elastic ring to retain said grub screw and said second connection element in said seat.

15. A device according to claim 1 , wherein said first connection element includes at least one fixing portion insertable into said first mechanical member.

16. A device according to claim 15, wherein the fixing portion of said first connection element comprises a threaded pin.

17. A device according to claim 15, wherein the fixing portion of said first connection element comprises a block with a T-shaped cross section provided with at least one cut.

18. A device according to claim 17, wherein it is provided at least one limiting element of the width of the cut inserted into a specific seat made in said cut.

19. A device according to claim 1 , wherein said first mechanical member comprises the body of a chuck and said second mechanical member comprises at least one jaw, or a supporting element for said jaw, which may be removably mounted on said chuck.

20. A device according to claim 1 , wherein said first mechanical member comprises a supporting block for one or more workpieces to be subjected to machining and said second mechanical member comprises at least one element to fix said one or more workpieces on said support.

21. A device according to claim 1 , wherein said first mechanical member comprises an adapter or of a tool of a modular tooling system and said second mechanical member comprises a basic adaptor of said modular system.