FI58826B - SERVICELUCKA FOER MONTERING I VENTILATIONSKANAL - Google Patents

Description

CTg ·;] [B] (11) ADVERTISEMENT 58 826 l J l 'utlAggningsskrift C Patent patented 10 04 1981

Patent patent

Vs (51) Kv.ik.3 / Int.ci.3 F 16 L 55/12 FINLAND —FINLAND (21) ftK * nttlh «k * nwi» - PMMtmtekning 773635 (22) HakamlspUvt - Ansdknlngidag 30.11.77 ^ ^ ( 23) AlkupUvt - Glltighatsdag 30.11.77 (41) Tullut | ulklMkcl - Bllvlt offantllg 31.05.79

Patent · la registered NihtiMtoip ^ is j. kuutjulk ^ and Pvm. _

Patent · och registerstyrelaan 'Araekan utiigd och uti.tkrifMn published 31.12.80 ^ (32) (33) (31) hodety etuolkeut — Begird prlorltet (71) Oy Pentair Ab, Vantaanrinne 6, 01730 Vantaa 2, Finland-Finland (FI) (72) Klaus Charpentier, Vantaa, Suomi-Finland (FI) (7k) Oy Kolster Ab (5k) Service hatch to be installed in an air duct wherein a substantially conical member is connected to the plug portion by a tightenable joint.

It is often desired to close the end of the air duct with an openable door that allows for various maintenance procedures. If the wall of the duct breaks, there is also a need to close the duct with a plug during the repair.

U.S. Patent No. 2,470,791 discloses an expansion plug to be mounted on a pipe, comprising a plate with a central threaded pin with a sealing ring fitted around its circumference. A nut is mounted on the threaded pin, which is connected via articulated arms to parts such as the brake shoe, which in turn act on the sealing ring. The diameter of the sealing ring is normally slightly smaller than the inner diameter of the pipe and the sealing is achieved by turning the nut towards the plate, whereby the articulated arms via the shoes expand the sealing ring by feeding the inner wall of the pipe.

2 58826

Although this plug itself is probably effective, it is complicated in structure and thus so expensive that its use in air conditioning ducts is out of the question. In addition to the articulated arms and clamping shoes, the installation of the sealing ring requires a special fastening ring with several screw-bolt connections, in which case corresponding seals must also be made in the sealing ring, which must still allow radial movement of the sealing ring.

Another hatch structure, which is quite common in practice, comprises two hatch halves placed in the channel against each other, the envelope surfaces of which expand, for example, like a truncated cone. A ring seal is fitted in the space bounded by the shell surfaces of the hatch halves and the wall of the duct. When the door halves are tightened towards each other, their casing surfaces press the ring seal outwards against the channel wall. A hatch operating according to this principle is disclosed, for example, in U.S. Patent No. 3,291,156.

Compared to the solution proposed in, e.g., U.S. Patent No. 2,487,991, such hatches are clearly simpler, but even in these structures, the use of two substantially equal plug plates increases material costs and manufacturing costs are further increased by forming expandable sheath surfaces.

The object of the present invention is to provide a new, simpler and more economically advantageous service hatch than known structures, in particular for ventilation ducts.

This is achieved by a service hatch according to the invention, which is mainly characterized in that the sealing ring is fitted to the cone circumference, whereby the tension

The tightening connection between the plug part and the cone can be, for example, a bolt-nut connection. Since the cone remains on the channel side, either a bolt or nut is fixedly connected to the end of the cone, whereby the joint can be easily tightened or removed by turning the nut outside the plug or the end of the bolt, respectively.

3 58826

The sealing ring is preferably provided with a groove receiving the circumference of the cone, so that it is securely held in place. To facilitate the expansion of the circumference of the cone, it is recommended to cut it open in the radial direction at suitable intervals.

The manufacturing costs of the hatch according to the invention are clearly lower than the manufacturing costs of the hatches used hitherto. It is also very reliable and easy and quick to install.

The following is an explanation of the invention with reference to the accompanying drawing.

Fig. 1 shows a longitudinal section of the end of the air conditioning duct with the service hatches mounted thereon, and Fig. 2 shows the structure seen from the direction of the duct.

The air duct is indicated by the number 1. The hatch mounted at its end comprises a plug part 3> having a diameter slightly smaller than the inner diameter of the duct I, a sealing ring 2 and its holding part 4 · The part 4 is made substantially conical and fastened to the plug part 3 by nut 5 and bolt 6 forming a joint. The nut 5 is fixedly connected to the tip of the cone 4.

When the cone and the plug are connected to the rest position, the cone 4 with its seals and the 2 plug 3 are of the same diameter, whereby the door can be inserted into or removed from the channel 1. When the bolt 6 is tightened, the cone 4 is compressed, whereby its circumference expands by pressing the plug 3 of the seal 2 against the wall of the channel 1 and thus closing the gap between the plug 3 and the channel 1. Min the door will be tightly and tightly locked in the duct. When the bolt 6 is removed, the circumference of the cone 4 again shrinks, whereby the seal 2 detaches from the wall of the channel 1. In order for the circumference of the cone 4 to be able to perform this expansion and contraction movement, the envelope surface of the cone has been cut open at suitable intervals along the circumference. Both cuts are marked with the number 8.