Device for the thermal binding of sheets

Abstract: Device for the thermal binding of sheets, mainly consisting of at least one support (5-5a-5B) for a binding element (3) of the type of which the inside of the back is provided with an amount of glue (4) which melts under the influence of heat, a heating element (6) co-operating with this support (5-5A-5B) or forming part thereof, detection means (7) to detect the presence of a binding element (3) in the device (1) and control and/or switching means (8) which on the one hand are connected to the detection means (7) and on the other hand are connected to the heating element (6) in order to switch it on and/or off, characterised in that said detection means (7) are applied underneath said support (5-5A-5B).

Description: The present invention relates to a device for the thermal binding of sheets, more specifically for the binding of sheets by means of a binding element which is provided on the inside of its back with an amount of glue which melts under the influence of heat. It is known that such devices mainly consist of a support on which a binding element can be placed with the binding back, and a heating element co-operating with this support or forming part thereof, whereby, due to the turning on of this heating element, the binding back heats up, the glue melts and the sheets to be bound penetrate in the glue. It is also known to equip these devices with detection means to detect the presence of a binding element in the device, and with control or switching means which, on the one hand, are connected to the detection means and, on the other hand, are connected to the heating element in order to switch it on and/or off, in such a way that the binding cycle takes place more or less automatically. Such a device is known e.g. from US-A-5 246 325. In the know embodiments these detection means consist of an optical eye which is applied sideways above said support, in such a way that the presence of a binding element on the support can be detected. These known embodiment, however, have several disadvantages. A first disadvantage consists in the fact that their working can be disturbed by filthiness, such as dust, material remainders and such like which end up in the device and place themselves in front of the optical eye. A second disadvantage consists in the fact that the presence of such optical eye disadvantageously influences the width of the device, and that in case of a plural device, in other words with several supports applied one next to the other, the use of such an optical eye, and thus also the automation of the device, are nearly excluded. The invention aims at a device which does not present the above-mentioned disadvantages. To this end, the invention consist in a device for the thermal binding of sheets, mainly consisting of at least one support for a binding element of the type of which the inside of the back is provided with an amount of glue which melts under the influence of heat, a heating element co-operating with this support or forming part thereof, detection mans to detect the presence of a binding element in the device, and control and/or switching means which, on the one hand, are connected to the detection means and, on the other hand, are connected to the heating element in order to switch it on and/or off, characterised in that said detection means are applied underneath said support. Due to the fact that the detection means are applied underneath said support, the working hereof cannot be disturbed and they do not influence the width of the device. Preferably, the detection means are not located directly underneath the support, but under the heating element co-operating with this support, presenting the advantage that the detection means do not influence the heat transfer from the heating element to the support. In those cases where the device is intended to be used for binding by means of binding elements which are provided with a binding back with a metal, more specifically steel profile, the detection means preferably consist of a magnetically sensitive element with reacts to the presence of the metal back in the device. According to an other embodiment, which can be used for all kinds of binding elements using fusible glue, the detection means according to the invention consist of, on the one hand, means which provide that said support moves when applying a binding element, preferably due to its weight and, on the other hand, a detection element which can detect the movement of the support, such as a switch, push-button, sensor or such like. In order to better show the characteristics according to the invention, some preferred embodiments are described hereafter as examples without any limitative character whatsoever, reference being made to the accompanying drawings in which: figure 1 schematically represents a cross-section of a known device; figure 2 represents a variant of figure 1; figure 3 schematically represents a cross-section of a device according to the invention; figure 4 schematically represents a section according to line IV-IV in figure 3; figure 5 represents, at an enlarged scale and for a practical embodiment, a section according to line V-V in figure 4; figure 6 represents a view similar to that of figure 4, but for an alternative embodiment. In figure 1 a know device 1 for binding sheets 2 in a binding element 3 is represented, more specifically in a binding element 3 which is provided with an amount of glue 4 which melts under the influence of heat. The device 1 hereby consists of a support 5 for the binding element 3, a heating element 6 co-operating with this support 5, detection means 7 to detect the presence of the binding element 3 in the device 1 and control and/or switching means 8 which, on the one hand, are connected to the detection means 7 and, on the other hand, are connected to the heating element 6 in order to switch it on and/or off. The detection means 7 hereby consist of an optical eye 9 which, because it necessarily has to be applied sideways next to the support 5, results in the disadvantages mentioned in the introduction. In the case where several supports 5-5A-5B are provided one next to the other, as represented in figure 2, the use of such an optical eye 9 is practically excluded. As represented in figures 3 to 6 this is remedied according to the invention by applying the detection means 7 underneath said support 5, 5A-5B respectively. In figure 5 a practical embodiment is represented more in detail, which is intended to be used for binding sheets 2 by means of a binding element 3 which is provided with a binding back 10 made of metal, more specifically a steel profile 11, whereby the detection means 7 consist of a magnetically sensitive element 12 which reacts to the presence of the metal profile 11 in the device 1. As schematically represented, this element 12 can consist of a movable magnetic element 13 which is movable vertically, and of means 14, such as a solenoid, which detect the movement of the magnetic element 13. The working hereby relies on the fact that the magnetic element 13 is attracted by the profile 11 at the moment the binding element 3 is placed on the support 5, which results in an electrical signal in the solenoid, such that through the control and/or switching means 8 the desired control of the heating element 6 is provided. It is clear that according to a variant use can also be made of other detection means 7 of which the working used magnetism, such as a read relay for detecting the movement of the element 13, or an element which creates a magnetic field of which changes in the magnetic field, due to the penetration of the profile 11 in this field, are electronically determined. In figure 6 an embodiment of the invention is represented whereby the detection means 7 consist of, on the one hand, means 15 which allow that the support 5 moves when applying a binding element 3, in this case due to the weight of the binding element 3 and the sheets 2, and on the other hand a detection element 16 which detects the movement of the support 5 and thus delivers a signal to the control and/or switching means 8. In the represented example, said means 15 consist of a springy hinge suspension 17 of the support 5, formed by, on the one hand a hinge connection 18 and on the other hand a support by means of a spring 19, such that the application of the binding element 3 with the sheets 2 on the support 5 results in that the support 5 is moved at the extremity 20. The detection element 16 for instance consists of a push-button, switch or sensor which reacts to the movement of the support 5 at the extremity 20. The working of this embodiment relies on the principle that the support 5 rotates around the hinge point 18 under the weight of the binding element 3 and the sheets 2, and that this movement is detected by the detection element 16, so that the control and/or switching means 8 are commanded. The working of the control and/or switching means 8 can be of a various nature. These control and/or switching means 8 can for instance consist of an electric and/or electronic circuit or switching system which turns the heating element 6 on as long as the detection means 7 detect the presence of a binding element 3 on the support 5. According to a variant, the control and/or switching means can also be equipped with a time circuit which provides that the heating element 6 is turned on after the application of a binding element 3 on the support 5, and which also provides that this heating element 6 is automatically turned off after a certain time. It is clear that these control and/or switching means 8 can also be connected to a display or pilot lights which inform the user of the device 1 whether or not the heating element 6 is turned on. In the simplest embodiment the detection means 7 and the control and switching means 8 are integrated in one whole. In such case they can consist of a push-button which closes the electric circuit of the heating element 6 when it is pressed. As represented in figure 3, the device 1 can comprise several supports 5-5A-5B located one next to the other, for the simultaneous treatment of several heating elements, whereby each support 5-5A-5B is provided with a separate heating element 6 and each support is also provided with separate detection means 7, as well as separate control and/or switching means 8.

Claims: Device for the thermal binding of sheets, mainly consisting of at least one support (5-5a-5B) for a binding element (3) of the type of which the inside of the back is provided with an amount of glue (4) which melts under the influence of heat, a heating element (6) co-operating with this support (5-5A-5B) or forming part thereof, detection means (7) to detect the presence of a binding element (3) in the device (1) and control and/or switching means (8) which on the one hand are connected to the detection means (7) and on the other hand are connected to the heating element (6) in order to switch it on and/or off, characterised in that said detection means (7) are applied underneath said support (5-5A-5B). Device according to claim 1, characterised in that said detection means (7) consist of a magnetically sensitive element (12) which reacts to the presence of a binding element (3) with a metal, more specifically steel, back profile (11). Device according to claim 2, characterised in that the magnetically sensitive element (12) consists of a movable magnetic element (13), which is movable vertically, and of means (14) which detect the movement of the magnetic element (13). Device according to claim 3, characterised in that the means (14) which detect the movement of the magnetic element (13), consist of a solenoid or such like which detects the change in the magnetic field. Device according to claim 1, characterised in that said detection means (7) consist of, on the one hand means (15) which allow that said support (5-5A-5B) moves when a binding element (3) is applied, and on the other hand, a detection element (16) which can detect the movement of the support (5-5A-5B). Device according to claim 5, characterised in that the means (15) which allow that said support (5-5A-5B) moves when a binding element (3) is applied, consist of a hinged suspension of the support (5-5A-5B,) and in that the detection element (16) consists of a switch, push-button or such like, which co-operates with the support (5-5A-5B). Device according to any one of the preceding claims, characterised in that it comprises several supports (5-5A-5B) placed one next to the other for the simultaneous treatment of several binding elements (3), whereby these supports (5-5A-5B) are placed immediately next to one another. Device according to any one of the preceding claims, characterised in that it comprises several supports (5-5A-5B) places one next to the other for the simultaneous treatment of several binding elements (3); in that these supports (5-5A-5B) are each provided with a separate heating element (6); and in that for each support (5-5A-5B) separate detection means (7) as well as separate control and/or switching means (8) are provided. Device according to any one of the preceding claims, characterised in that the detection means (7) are located underneath the heating element (6).

Inventors: PELEMAN GUIDO, PELEMAN, GUIDO
Applicants: UNIBIND CYPRUS LTD, UNIBIND (CYPRUS) LIMITED
Application year: 1997
Main classification: B42C9
IPC codes: B42C9, H05B3