CHAIN-TYPE ACTUATOR TO A SHUTTER Technical Field

The present invention relates to a device for anchoring the free end of a chain of a chain-type actuator to a shutter. Background Art

Chain-type actuators are currently known and widespread which allow the automatic opening and closing of shutters, especially of shutters located in positions that are difficult to reach, such as for example skylights of a gymnasium or of an industrial building.

These actuators comprise, within a box-like container that is fixed to the frame of the casing related to the shutter, a chain that is guided so as to slide by guiding elements within a preset path that leads outside through an opening in such box-like container. The chain is of the type that can flex only in one direction and is prevented from flexing in the opposite direction.

The chain has a free end that is associated with a device for anchoring to the corresponding shutter, which is composed of an engagement terminal, jointly fixed to the free end of the flexible element, and a complementary engagement block, associable with the engagement terminal, jointly fixed to the shutter.

Such an anchoring device is disclosed in EPl 522667 in the name of this Applicant.

The engagement terminal has, transversely to the direction of action of the chain, mutually opposite protrusions for mating with complementary holes formed in two mutually opposite elastically deformable wings that belong to the engagement block that is fixed to the shutter.

These mutually opposite elastically deformable wings are constituted by the wings of a C-shaped lamina that is fixed to the shutter for example by means of threaded connections. The engagement block also comprises an outer shell, which covers the C-shaped lamina and interlocks reversibly with such wings.

Such outer shell is also C-shaped, so as to form a central recess for accommodating the engagement terminal. At the holes in the wings of the C-shaped lamina, the shell has access openings for the protrusions for mating the engagement terminal to such holes.

Insertion of the engagement terminal occurs by lateral elastic deformation of the wings and insertion of the protrusions of the terminal in the respective holes in the wings.

Once the protrusions are within the seats, the elastically deformable wings return to the original position.

The ends of the wings have an outward fold and can be accessed from outside the shell through such openings, so that even with a simple punching tool or screwdriver it is possible to act on the fold, flex the wing and disengage the terminal.

In this embodiment, the locking of the terminal with respect to the block occurs easily by inserting a punching tool or the head of a screwdriver in one of the openings in order to press outward the corresponding fold at the end of the corresponding wing.

Although this device is functional and appreciated and therefore widespread, it has aspects that can be improved.

The main aspect that can be improved is the relative complexity of the engagement block, which as mentioned comprises a C-shaped metallic lamina that must be provided by means of a sequence of operations for pressing and bending a metal plate, which require a certain time and a certain labour, in addition to the cost of the raw material.

A covering shell made of plastics is associated with the C-shaped metallic lamina and must be fitted on the lamina after it has been fixed to the casing. Further, the disengagement of the terminal from the block requires intervention on the part of an operator with a pointed tool, in order to flex a wing of the C-shaped lamina so as to free a protrusion of the terminal, as described above, Disclosure of the Invention

The aim of the present invention is to provide a device for anchoring the free end of a chain of a chain-type actuator to a shutter that is capable of obviating the drawbacks exhibited by known devices.

Within this aim, an object of the present invention is to provide a device that is simpler to assemble and install than known devices.

Another object of the present invention is to provide a device that is simpler to disengage.

Another object of the present invention is to devise a device that is cheaper to provide. Another object of the present invention is to provide a device for anchoring the free end of a chain of a chain-type actuator to a shutter that can be manufactured with known systems and technologies.

This aim and these and other objects, which will become better apparent hereinafter, are achieved by a device for anchoring the free end of a chain of a chain-type actuator to a shutter, comprising an engagement terminal, which is coupled to the free end of said chain, and a complementary engagement block, which can be mated to said engagement terminal, jointly fixed to the shutter, said device being characterized in that

- said engagement terminal comprises a portion for connection to the chain, from which a head protrudes which has lateral protrusions for engagement with said engagement block,

- said engagement block comprises a main body, to be fixed to the shutter and on which there is a first seat, for the insertion of said head of the engagement terminal, and a second seat, for the coupling of an extraction- preventing insert provided with means for preventing the unwanted escape of said head from said first seat, said insert being provided with a release lever that protrudes, and is available to a user, from a corresponding sliding slot formed on said main body. Brief description of the drawings Further characteristics and advantages of the invention will become better apparent from the following detailed description of a preferred but not exclusive embodiment thereof, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a side view of a device according to the invention associated with a chain-type actuator, which in turn is applied to a shutter shown in the open configuration;

Figure 2 is a perspective view of the engagement terminal associated with the chain of a chain-type actuator;

Figure 3 is a perspective view of the device according to the invention;

Figure 4 is a sectional top view of the device according to the invention in the assembled condition;

Figure 5 is an exploded perspective view of the device according to the invention; Figure 6 is another sectional top view of the device, with the terminal in a different angular position with respect to the engagement block;

Figures 7 to 9 show the sequence of insertion of the head of the terminal in the block of the device according to the invention. Ways of carrying out the Invention With reference to the figures, a device for anchoring the free end of a chain of a chain-type actuator to a shutter according to the invention is generally designated by the reference numeral 10.

The device 10 for anchoring to a shutter 1 1 the free end of a chain 12 of a chain-type actuator 13 comprises an engagement terminal 14 and a complementary engagement block 15, which can be mated with the engagement terminal 14.

The engagement teiminal 14 is coupled to the free end of the chain 12 and is thus associated with a frame 16 of the shutter 1 1 ; the chain-type actuator 13 is fixed to the frame 16, while the engagement block 1.5 is jointly fixed to the shutter 1 1.

The engagement terminal 14 comprises a portion 17 for connection to the chain 12.

A head 18 protrudes from the portion 17 and has lateral protrusions 19 and 20 for engagement with the engagement block 15» The engagement block 15 comprises a main body 21 , to be fixed to the shutter 11.

A first seat 22 for the insertion of the head 18 of the engagement terminal 14 and a second seat 23 for the coupling of an extraction- preventing insert 24 are provided on the main body 21 , The extraction-preventing insert 24 is provided with means, described in greater detail hereinafter, for preventing the unwanted escape of the head 18 from the first seat 22.

The extraction-preventing insert 24 is provided with a release lever 25, which protrudes, so as to be available to a user, from a corresponding sliding slot 26 formed on the main body 21.

The extraction-preventing insert 24 comprises a central part 27, from which an extraction-preventing tab 28 cantilevers out and is provided with portions, 29 and 30 respectively, designed to face the first seat 22 at the protrusions 19 and 20 of the head 18 of the terminal 14 and on the opposite side with respect to the bottom 31 of the first seat 22, arranging themselves so as to prevent the exit of the protrusions 19 and 20 from the first seat 22, as clearly shown in Figure 9.

The extraction-preventing tab 28 is fork-shaped, and a first portion 29 thereof, which is adjacent to the central part 27, forms a first undercut for the first protrusion 19 of the head 18, and a second portion 30, which lies opposite the first portion 29 and is connected thereto by means of an elastically deformable bridge 32, forms a second undercut for the second protrusion 20 of the head 18.

The extraction-preventing insert 24 comprises an elastically deformable positioning lug 33, which protrudes on the opposite side with respect to the extraction-preventing tab 28.

The positioning lug 33 is designed to maintain the correct extraction- preventing configuration of the insert 24 in its seat 23.

The positioning lug 33 is designed to flex elastically in order to allow the temporary and reversible translational motion of the insert 24 for the engagement and disengagement of the head 18 of the terminal 14, an operation which is described in greater detail hereinafter.

The first seat 22 is provided by an upper opening for the insertion of the head 18, from which a front opening 34 widens for a portion 35 for connection between the head 18 and the portion 17, for connection to the chain, of the terminal 14.

The upper opening is provided with recesses 36 and 37 suitable for the passage of the protrusions 19 and 20 of the head 18 toward a respective accommodation recess 38 and 39. The corresponding accommodation recesses 38 and 39 are each formed between the bottom 31 of the first seat 22 and the corresponding overlying portion 29 or 30 of the extraction-preventing tab 28 of the extraction-preventing insert 24.

The front opening 34 and the accommodation recesses 38 and 39 for the protrusions 19 and 20 have such dimensions as to allow a certain rotation of the head 18 in the first seat 22 about an axis that is substantially perpendicular to the arrangement of the chain 12, said rotation of the head

18 being necessary so that the chain 12 does not flex inappropriately during traction or pushing on the block 15 and therefore on the shutter 1 1 , as clearly shown in Figures 4 and 6. The main body 21 has, in the end regions, two holes 40 and 41 for a corresponding number of threaded fixing elements.

The terminal 14, the main body 21 and the extraction-preventing insert 24 are made of plastics. The operation of the device according to the invention is as follows.

The terminal 14 is hinged to the chain 12.

The extraction-preventing insert 24 is inserted in its seat, which is the second seat 23, by inserting it in the main body 21 from its rear part, i.e., the one designed to be arranged adjacent to the shutter 1 1. The engagement block 15 that contains the extraction-preventing insert 24 is fixed to the shutter 1 1 by way of threaded elements to be inserted in the through holes 40 and 41.

With the insertion of the insert 24 in the main body 21 , the lever 25 protrudes from the slot 26 and the two portions 29 and 30 of the extraction- preventing tab 28 are arranged so as to affect the recesses 36 and 37 for the passage of the protrusions 19 and 20 of the head 18 of the terminal 14,

In this situation, the head 18 is first inserted in the first seat 22, as shown in Figure 8.

The protrusions 19 and 20 come into contact with the respective portions 29 and 30, which in the regions of contact have bevels 42 and 43 that are adapted to facilitate insertion.

The descent of the head 18 leads to the flexing of the bridge 32 of the extraction-preventing tab 28, to the flexing of the positioning lug 33 and to the temporary divarication of the portions 29 and 30. Figure 9 shows the head 18 with its protrusions 19 and 20 on the bottom 31 of the first seat 22, with the extraction-preventing portions 29 and 30 that lie above the protrusions 19 and 20, preventing their upward extraction.

The positioning lug 33 has returned to its initial configuration. The release of the terminal 14 from the block 15 is performed as described hereinafter.

The lever 25 is operated manually and moved within the slot in the direction of compression of the lug 33, i.e., to the right as regards what is shown in the accompanying figures. The movement of the lever 25 entails the translational motion of the central part 27 of the insert 24, with consequent spacing of the first extraction-preventing portion 29 from the first protiusion 19 and with consequent divarication of the second extraction-preventing portion 30, a part of which, for connection to the bridge 32, rests against the edge of the back 45 of the first seat 22, producing an instantaneous axis of rotation.

In this configuration, the head 18 can be extracted from its first seat 22.

In practice it has been found that the invention thus desciibed achieves the intended aim and objects. In particular, the present invention provides a device that is simpler to assemble and install than known devices.

Moieover, the present invention provides a device that is simpler to release, since one does not have to act with screwdrivers or other tools.

Further, the present invention provides a device that is cheaper to manufacture, since it lacks contoured metallic laminas and is constituted by three elements made of plastics: the terminal 14, the main body 21 and the insert 24.

Moreover, the present invention provides a device for anchoring the free end of a chain of a chain-type actuator to a shutter that can be provided by means of known systems and technologies.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; all the details may further be replaced with other technically equivalent elements. In practice, the materials employed, so long as they are compatible with the specific use, as well as the dimensions, may be any according to requirements and to the state of the art.

The disclosures in Italian Patent Application No. PD2008A000227 from which this application claims priority are incorporated herein by reference

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.