This invention refers to the development of an assembly process for a door closing device and its resulting device, using a door closing spring. This process is tremendously helpful for the assembly, as it only requires two sets that are joined through a safety lock.

The mechanisms currently known have three sets, whereby the assembly system is made thanks to a thread to join the sets to one another, thereby resulting in a complex assembly process. The Pl 9605812-9 patent presents an automatic door closing system, whose assembly process is made up by three sets: a complete shafting, an external part and a connecting member. The assembly process claimed entails first and foremost the external assembly of the action pin and the trajectory curve disk to the pressure roll through pins for the entire set to, then, be supported on a bearing. During this process a coupling part with a protrusion and an internal thread is connected to this set by piston pins through fishplates to form the first set called the complete shafting. A seat, a ring port and a stepped hole, which has the same diameter as the protrusion with the current internal thread in the coupling part, make up the external part, and second part in this system. This external part will function as a piston and receive the complete shafting through the protrusion in the coupling part. After the joining, the connecting member, i.e., the third element in the process, which has an external thread, will be coupled to the set and screwed to the internal thread of the protrusion in the coupling part of the complete shafting, and will be limited by the said protrusion on the said connecting member, thereby forming one single set. Those systems, formed by three [parts in the total] set, require great skills from the technician when assembling them, not to mention the further time due to the complexity of the assembly process and to the fact that the sets must absolutely be tapped inside the cabinet with quite some p erfect joining of the sets described above.

This report refers to a brand new and unusual assembly process that results in a door closing device and works as follows: a so-called cam set is first inserted inside the base through a front opening. Then, a so-called shafting set is inserted inside the base through the back opening until the connecting pin fits in the internal milled part of the piston. The shafting set rotates 90° until blocking the connecting pin. The said joining of the shafting set to the cam set inside the base is ensured by inserting a safety lock to enable a perfect joining of the set.

The mechanism of this invention is quite creative and simple, and solves all the problems described in the current mechanisms for this application, since it is made up by only two sets, a shafting set and a cam set. A piston and a shaft make up the first set. One of the piston's ends has an internal thread to enable the perfect joining to the shaft that has an external thread on one end. The piston has also been internal milledly throughout its internal diameter and the transverse section to receive the safety lock. The piston connection to the shaft forms the shafting set to be preassembled outside the base.

The cam set is made up by a connecting pin with facetted ends, a cam, bearings, fixing pins, a break bushing, as well as an upper and a lower fishplate. Those parts are also to be preassembled outside the base to form the cam set.

In order to fully understand the assembly process of the door closing device and its resulting device in question in this invention, the detailed description of this process is done based on the following figures:

Figure 1 - Assembled Set Section View

Figure 2 - Perspective

Figure 3 - Upper View

Figure 4 - Side Section View

Figures 1 to 4 illustrate the assembly process for a door closing device and its resulting device, which is made up by a shafting set (8) and a cam set (3). The assembly is to be done step by step as follows: the cam set (3) is first inserted inside the base (9) through the opening (20). The shafting set (8) is then inserted inside the base (9) through the opening (10) until the connecting pin (11) fits in the internal milled part (5) of the piston (1). The shafting set rotates (8) 90° until blocking the connecting pin (11) in the internal milled part (5).

The joining of the shafting set (8) to the cam set (3) inside the base (9) is ensured by inserting the safety lock (12) with a hole (13) through the opening (20) and fixing it onto the pin (11) below the section (6), thereby enabling a perfect joining of the set.

The shafting set (8) is made up by a piston (1) and a shaft (2). The piston (1) has an internal thread (4) with a internal milled part (5) throughout its internal diameter and the section (6). The shaft (2) is characteristic for having an external thread (7) and a necking (21). The piston (1) is connected to the shaft (2) by tightening the necking (21) with the wrench between the internal thread (4) and the external thread (7) to form the shafting set (8) to be preassembled outside the base (9).

The cam set (3) is made up by a connecting pin (11) with facetted ends, a cam (15), bearings (14), fixing pins (16), a break bushing (18), an upper fishplate (17) and a lower fishplate (19). Those parts are also to be preassembled outside the base (9) to form the cam set.