CS216837B2 - Appliance for melting and dosing the thermoplastic pasting materials - Google Patents

Abstract

In a hand held heated dispensing device contact of an operator's hand with sensors 8 carried by hand-grip 2 serves to switch the device from a low temperature setting to a high temperature setting for a melting chamber (not visible) to which solid adhesive 5 is fed by operation of trigger 4 to dispense molten adhesive from nozzle 6. When the device is put down (e.g. for positioning a component to be adhered in place) removal of the operator's hand from contact with the sensors 8 causes switching back, if desired after a short time delay, to the low temperature setting. This arrangement reduces the time necessary for the device to be brought up to temperature each time it is required to be used. <IMAGE>

Description

The invention relates to a device for melting thermoplastic adhesives and dispensing molten adhesive with at least two controlled heating elements and a housing partially adapted to form a handle with an electrical supply and a nozzle.

Thermoplastic adhesives will be increasingly used in joining techniques. Their advantages are the short curing time, that no harmful solubilizing agents are needed and that there is also the possibility of fusion bonding and disassembly. In addition to a purely factory processing method, such as in the footwear industry, thermoplastic adhesives are also suitable for assembly work. However, there is a problem that there are sometimes longer breaks between applications. If the device is completely switched off during these breaks, it will take a relatively long time for the device to reach operating temperature again.

In one of the known apparatuses, the time required for reheating the apparatus is processed by the preheating device consisting of two stages. In the first phase, the desired temperature is achieved by connecting a strong heating element. As soon as this temperature is reached, it is switched by means of a temperature-controlled switching element to a weaker heating element, which is used only for dispensing adhesive and which is set to the desired melting temperature.

There is a risk of overheating even if there is no dose through the unit for a long period of time. To avoid this, the device should always be switched off during long breaks. With this in mind, the operator must always decide whether a long or short break will follow. This is in some cases difficult to predict in spite of the burden on the operator. Frequent switching off of the device causes undesirable waiting times, if it is switched off little or not at all, there is a risk of overheating.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a device for melting thermoplastic material and to prevent overheating as well as strong cooling during a break.

The above-mentioned drawbacks are eliminated by the device according to the invention, which is based on

Claims (3)

Apparatus for melting thermoplastic adhesives and dispensing molten adhesive with at least two controlled heating elements, with one casing partially adapted in the shape of a handle with an electrical supply and with a nozzle, characterized in that it is provided with a button (4) disposed in the handle (2) for controlling the displacement of the adhesive body (5) into the housing (1), the side facing away from the handle (2j) is provided with a button disposed in the handle for controlling the displacement of the adhesive body into the housing on the side facing away from the handle air cooling gaps are provided, the handle being provided with a manually operable temperature degree switch on the side The manually operable switch is designed as mechanical, for example electromechanical or electronic. With the device according to the invention, the operator is relieved of the decision on the length of the operating breaks. A further advantage is that the apparatus is not generally cooled, it is only heated to the lowest temperature necessary for the adhesive mass, which is not harmful to the parts of the apparatus. The time required to heat up to the working temperature is also very short when the device is used again. The invention is explained in more detail with reference to the drawing, which shows a device according to the invention from a side view. The device according to the invention consists essentially of a housing 1 with a side handle 2. The handle has an electrical connection 3 as well as a button 4. When using the button 4, the adhesive body 5, e.g. tavbu. This will compress the portion of the molten adhesive contained in the melting chamber and exit the feed nozzle 6 at the front end of the housing. 1. Air cooling gaps 7 are formed on the side of the housing 1 facing away from the handle 2. The handle 2 has a switch on the side 8. Switch 8 is used to switch from a heavier to a weaker heating element when the handle 2 is released. In principle, any switching elements such as electromechanical switches, push buttons and the like can be used for switching. A mechanical closure is used for these elements, and it is therefore preferred that a touch-sensitive sensor is provided on the handle. Clamping is done by simply touching the hand that surrounds the handle. Especially suitable are electronic switches, which are widely used in electronic toys and are therefore very suitable. OF THE INVENTION air cooling gaps (7), wherein the handle (2) is provided with a manually operable temperature degree switch (8) on the side. Device according to claim 1, characterized in that the manually operable switch (8) is designed as mechanical, for example electromechanical. Device according to claim 1, characterized in that the manually operable switch (8) is designed as electronic.