Intrinsically safe control device for controlling the operation of a working machine

Abstract

A control device for controlling the operation of a mechanical, electric, pneumatic, hydraulic / oil-powered or similar working machine, the control device comprising a base body, a rotating shaft is mounted in the center of the base body, the rotating shaft is coupled to a knob rotating on the base body in a torsion manner, the shaft is functionally connected to an electrical connector, the electrical connector is suitable for supplying power to the working machine when the knob is in a first operating position on the body and is suitable for interrupting the supply power when the knob is in a second operating position on the body. The knob supports a selector member for selecting the movement of the knob on the base body, the selector member is integral with the knob in a torsion manner, but can be moved in a manner orthogonal to the knob, the selector member includes an interception device, the interception device is suitable for cooperating with an anti-interception device provided in the base body, the cooperation between the interception device and the anti-interception device prevents the rotation of the knob placed on the base body.

Description

Technical Field

[0001] The invention relates to a control device for controlling the operation of a working machine. Background Art

[0002] The term "User" refers to an operating machine, in particular a machine tool used for wood, metal or glass processing operations; the term "User" also refers to a substation or switchboard or other device, machine or electrical, mechanical, pneumatic, hydraulic, oil-hydraulic or other type of device, machine or equipment, which can enable and / or disable its operation upstream thereof.

[0003] The phrase "control means for controlling the operation of a working machine" refers to means for controlling the activation and deactivation of the operation of said working machine. Such control means comprises a knob which rotates on a fixed body and can be in two operating positions: in a first operating position, the knob allows activation of such a working machine (i.e. the operation of the working machine), and in a second position, the knob deactivates the operation of the working machine.

[0004] In light of the above considerations, it is known that, for example in the field of machine tools, there is a need to provide safety systems that prevent such machines from shutting down unexpectedly; this is primarily to prevent mechanical and electrical problems with the machine.

[0005] For this purpose, the devices controlling the activation and deactivation of the working machine, i.e. the control of whether it is operated or not, are usually placed at different positions relative to the control panel of the machine or working machine (with regard to the power supply to the machine), so that intervention in the above-mentioned devices can only be carried out intentionally and cannot be caused by accidental manipulation by the person responsible for the operation of the machine. This is also determined by the current regulations.

[0006] However, the decentralized positioning of the control devices (relative to the control panel of the machine) may present problems related to the distance between the devices and the machine. For example, a person or machine operator will move from the switchboard control panel to the control device to enable the machine, thereby preventing the person from fully monitoring the entire machine (even for a short period of time).

[0007] Other problems associated with this spacing distance of the enabling / disabling device for enabling / disabling the power supply (i.e. enabling / disabling the operation of the working machine) may exist in embodiments of the device comprising a knob located on a fixed body: these components must comply with very strict regulations and cannot be modified unless the function of controlling said enabling is not invalidated.

[0008] DE 19939717 describes a manually operated device suitable for use with a reversing device having a knob. This device has some of the features indicated herein.

[0009] DE 20009737 describes a device similar to the one disclosed in DE 19939717, comprising a base body on which a knob is present, the knob comprising an interceptor device adapted to cooperate with an interceptor countermeasure device to prevent the knob from rotating, the interceptor countermeasure device being integrally formed with such base body. Such rotation is only possible when the device and the countermeasure device do not cooperate with each other. Summary of the invention

[0010] The object of the invention is to provide a control device for controlling the operation of a working machine which always and in any case allows correct operability, but which always allows activation and deactivation of said operation in an active manner, thereby avoiding that such a working machine is inactively switched off.

[0011] Another object is to provide a device of the above-mentioned type which is simple to manufacture and which can be adapted to similar control devices according to the prior art with a minimum of intervention, even if such similar control devices are already in use.

[0012] Another object is to provide a control device of the above-mentioned type which allows an operator of a working machine, for example a machine tool, to intervene in the device without leaving the machine, thereby maintaining practical visual supervision at any time during the machining operation.

[0013] These and other objects will be apparent to those skilled in the art and are achieved by a control device for controlling the operation of a working machine according to aspects herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to better understand the present invention, the following drawings are attached herewith for illustrative purposes only and not for limiting purposes, in which:

[0015] Figure 1 is a top view of the device according to the present invention;

[0016] Figure 2 yes Figure 1 An exploded perspective view of the device shown in ;

[0017] Figure 3 yes Figure 1 A top perspective view of the device shown in ;

[0018] Figure 4 is based on Figure 1 A cross-sectional view of the cross section 4-4 in FIG. 1 , wherein the device according to the present invention is in a first operating position;

[0019] Figure 5 is similar to Figure 4, the device according to the invention is in a second operating position;

[0020] Figure 6 Shown according to Figure 1 A cross-sectional view of section 6-6 in FIG. 1 , wherein the device according to the present invention is in a first operating position;

[0021] Figure 7 is similar to Figure 6 , the device being in a second operational position; and

[0022] Figure 8 is based on Figure 7 Cross-sectional view of cross section 8-8 in FIG. DETAILED DESCRIPTION

[0023] With reference to the above-mentioned figures, a device according to the invention is generally indicated by the reference numeral 1. The device comprises a base body 2 comprising two parts 3 and 4 coupled to each other by means of a snap-fit ​​coupling; Figure 2 Screws 5 are shown for fixing the part 3 (and therefore the base 2) to a control panel (not shown) of the working machine. It goes without saying that the restraint of the base 2 to the panel can be carried out by any other known means. In addition, the base 2 comprises a bottom seal 6, which is coupled to the (lower) part 3 of the base 2 in a manner known per se.

[0024] This component and seal have respective central holes 3A, 4A and 6A suitable for housing a rotating shaft 10 in the base 2. The seal 11 is inserted in an annular recess 12 of the base 13 of such shaft 10.

[0025] Said shaft is coupled in a manner known per se to an electrical connector, which is limited by the shaft's position relative to the base 2 to allow or prevent the activation of a working machine; for example, the position occupied by the shaft 10 may allow the supply of electrical power to a working machine (not shown), such as an operating machine, for example a machine tool for wood, metal, glass working operations; or such a working machine may be a transformer substation, a switchboard, a device or the like. Such a shaft comprises a grooved or toothed portion 15 adapted to project from a hole 4A of the (upper) portion 4 of the base 2 into a cavity 16 defined by a circular shoulder 17 rising from a free plane 18 in the upper portion 4A of the base 2.

[0026] A knob 19 is housed in said cavity 16, having a body 20 adapted to be torsionally coupled to the grooved or toothed portion 15 of the shaft 10 and rotatable within said cavity 16. By way of example, the knob 19 has a body 20 of circular cross section, having an edge 21 defining a recess 23 on an upper surface 22 of the body. From this upper surface 22 rises an at least partially hollow block 25 (or gripping portion of the knob), said block having a hole 26 adapted to receive the portion 15 of the shaft 10 in torsion engagement (obtained in any known manner). By way of example, a screw 29 axially couples said shaft 10 to said knob 19.

[0027] The hole 4A of the upper part 4 of the base 2 also penetrates a central portion 31 of the lower part 3 of the base 2, which protrudes inside the above-mentioned cavity 16. The central portion 31 comprises a plurality of shoulders 33 angularly separated and circularly delimiting recesses 35 between them.

[0028] The recesses are spaced apart from one another by an angle of, for example, 90°.

[0029] Corresponding to said central portion 31, there is a parallel elastic arm 38 protruding from a lower portion 39 of a member 40 superimposed to one end flat portion 24 of the block 25 and serving as a selector member (to be described below) suitable for locking and releasing the rotation of the knob 19 in the cavity 16, said arm 38 being snapped (through its hook-shaped end 38A) into a body 42 inserted into a seating 43 present in the block 25. The body 42 is suitable for being positioned in said recess 35 so as to define a first operating position of the knob 19, in which it allows the supply of electric power to the working machine, and a second operating position in which it interrupts said supply of electric power (reached by rotating the knob, according to a mode to be described below, with the permission of such a rotating release member).

[0030] The selector member 40 has a wide hole 45 corresponding to the screw 29 and wider than the screw 29 so that the screw does not interfere with the said members.

[0031] The body 42 comprises a central hole 47 adapted to house a corresponding spring 48 placed on a pivot portion 49 projecting towards a block portion 50 of the block 25, the pivot portion 49 being delimited by two slots 51 present in the block and adapted to receive in passing therethrough the arms 38 of the selector or locking / release member 40. The selector or locking / release member 40 is thus always associated in a torsion manner with the knob 19, but can be moved axially (in the direction of the longitudinal axis M of the device 1) by the movement of the arms 38 in the slots 51.

[0032] This axial movement (i.e., along the axis M) makes it possible to lift the selector member 40 from the block 25 of the knob 19 in the rest position; this upward movement is carried out by dragging the body 42, which causes the spring 48 to act (contrast), which tends to push this body inside the block 25, that is, to push it towards and on the central part 31 of the lower part 3 of the base 2. It goes without saying that the body 42 itself can have elastic protrusions cooperating with the spring 48 or as an alternative to the spring 48, in order to obtain the said purpose of action.

[0033] By said dragging, the body 42 is raised from the recess 35 of this central part 31 and leaves it. It is thus possible to rotate the knob 19 placed on said central part 31, without ever removing the hand from the selector member 40 (and therefore from the block 25 of the knob 19 which is integral in a twisting manner with the member 40), until said bodies 42 are not positioned corresponding to other recesses 35 of the part 31 and their respective springs 48 push them into such recesses 35, thus locking the rotation of the knob 19 itself. In fact, upon release of the member 40, the knob 19 comes to a stable stop in the second operating position.

[0034] Note that member 40 does not support loads, since the torsional forces suitable for rotating the knob 19 are supported only by the body 20 of the knob itself. In particular, the rotation of the knob occurs only by acting on the above-mentioned block 25 (or the gripping part of the knob), which is common in every control device having a knob.

[0035] This rotation is also performed by the shaft 10, which is integral in a torsion manner with the knob (or even better, only with the block 25 passing through the hole 26), thus interrupting / enabling the supply of power to the working machine. Therefore, under this rotation, the load is not applied to the member 40 superimposed on the flat part 24 of the block 26 and, as mentioned above, the member 40 includes the screw 29 without the screw 29 interfering with said member 40.

[0036] It is noted that the arm 38 never extends from the slot 51 and never separates from the body 42 , which is coupled with the arm 38 via a snap-fit ​​coupling.

[0037] Furthermore, the recesses 35 of portion 31 may be any even number (e.g., four as shown in the figure) and may be separated at any angle depending on the position of a connector (not shown) functionally connected to the shaft 10 (i.e., the shaft may directly or indirectly engage the connector to supply power or not to the working machine, thereby enabling or disabling operation of the working machine).

[0038] According to the present invention, a control device is provided for controlling the rotation of the knob 19 for supplying power to the working machine or not supplying power to the working machine.

[0039] Such a device comprises a blocking / releasing member and parts (such as, for example, the body 42 ) that are easy to manufacture and install in order to obtain a (complex) knob 19 for selectively controlling the power supply.

[0040] As described above, this control is achieved by moving the knob from a first position (wherein the button hole 60 is positioned, for example, corresponding to a value of "0"), such as Figure 1 and Figure 3 ) is rotated toward a second operating position (not shown) in which the buttonhole is positioned, for example, corresponding to the value “1”. These values ​​are highlighted on the bottom of the cavity 16 of the upper part 4 of the base body 2.

[0041] The invention has been described as being able to enable a working machine (for example in the case of an electric motor) by supplying power to the working machine. Obviously, the control device for controlling the operation (which, as mentioned above, is meant to enable, but also to disable, the operation of the working machine) can be used in the case where the working machine is operated in pneumatic, hydraulic, oil-powered or mechanical mode, or by means of an actuator, such an actuator (such as a pump, etc.) can be activated or deactivated via a knob 19 of the actuator installed in an electric, pneumatic or similar power supply network. For example, the knob 19 can operate or close a valve for supplying fluid to the working machine.

[0042] Obviously, based on the above description, other solutions are possible and should be considered to fall within the scope of the invention as described in various aspects herein.

Claims

1. A control device (1) for controlling the operation of a working machine, the device comprising a base (2) in the center of which a rotating shaft (10) is mounted, the rotating shaft (10) being torsionally coupled to a knob (19) rotating on the base (2), the shaft (10) being functionally connected to a supply device, the supply device being adapted to supply the working machine when the knob (19) is in a first operating position on the base and to interrupt the supply when the knob is in a second operating position on the base, the knob (19) being provided with a selector member (40) for selecting the movement of the knob (19) on the base (2), the selector member (40) being torsionally integral with the knob (19), the selector member (40) being movable orthogonally relative to the knob along a longitudinal axis (M) of the device (1), And the selector member (40) includes an interception device, which is suitable for cooperating with an anti-interception device arranged in the base (2), the cooperation between the interception device and the anti-interception device prevents the knob (19) from rotating on the base (2), the separation of the interception device and the anti-interception device enables the knob (19) to rotate from the first operating position to the second operating position, and the cooperation between the interception device and the anti-interception device prevents the knob (19) from rotating from the first operating position to the second operating position, the selector member (40) can be elastically moved along the longitudinal axis (M) of the device (1), and the selector member (40) is always connected to the gripping part or block (25) of the knob (19) and superimposed on the end flat part (24) of the block (25), characterized in that The selector member (40) comprises a protruding arm (38) which protrudes from a lower part (39) of the selector member (40) itself and is inserted into a slit (51) of the end flat portion (24) of the gripping portion or block (25) of the knob (19), the arm (38) being coupled to a body (42) which is inserted movably into a corresponding seating portion (43) present in the gripping portion or block (25), the body (42) being adapted to move in the seating portion (43) so as to be subjected to elastic forces and to define the interception device.

2. The device according to claim 1, characterized in that The elastic force is alternatively generated by a spring (48) cooperating with the corresponding movable body (42) or by the elasticity of each movable body (42).

3. The device according to claim 2, characterized in that Each spring (48) is inserted into its respective hole (47) in the corresponding movable body (42).

4. The device according to claim 1, characterized in that The movable body (42) is adapted to cooperate with recesses (35) present in the portion (31) of the base (2) of the control device (1), the recesses being separated from one another in such a way as to be circular and to define the operating position of the knob (19), the recess being the anti-interception device.

5. The device according to claim 1, characterized in that The power supply device is an electrical connector.

6. The device according to claim 1, characterized in that The supply device is alternatively a valve.

7. The device according to claim 1, characterized in that The base (2) of the knob is associated with a control panel of the working machine.

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