WO2020178644A1

WO2020178644A1 - Snap connection

Info

Publication number: WO2020178644A1
Application number: PCT/IB2020/051051
Authority: WO
Inventors: Marek Prymon
Original assignee: Thessla Green Sp. Z O.O.
Priority date: 2019-03-04
Filing date: 2020-02-11
Publication date: 2020-09-10
Also published as: PL429141A1; PL240623B1

Abstract

The subject of invention is a line push-in butt connection of two structural components, at least one of which is made of flexible plastic, especially for a detachable connection of parts (A, B) of the insulation housing of ventilation and air- conditioning equipment, containing a groove (1) and tongue (2), made in the adhesion plane (P-P) along the edges of the parts to be connected (A, B) and which, after a coaxial connection, have complementary shapes in the axis of symmetry (S- S), characterized in that the connection profile in order from the adhesion plane (P-P) is defined by a keyway (1.1) of the groove (1) of height (hi) and the smallest width (b1) of the walls which at the ends connect with bulges (1.2, 1.3), having a shape similar to that of a flattened letter 'S' and its mirror image on the opposite bulge, and which at the top section are facing outwards, at a depth (g1) have the largest width (s1), making it possible to press the bulge (1.2) into the keyway (1.1) within the range of elastic deformation of the materials, while at the bottom the bulges (1.6, 1.7) are facing to the inside of the connection and at the depth of (i1) have the smallest width (j1) and their lower ends are connected at the bottom of the groove (1.4.) with a width of (u1) at the groove height (H), whereas, while maintaining complete similarity of the cross-sectional shape, corresponding to the aforementioned groove dimensions (1) the dimensions of the tongue (2) (h2, b2, g2, s2, h, u2, i2, j2) are different and, when combined, form at the height of the connection loose fits with a gap (x,y) or tight fits (w,z) within the range of elastic deformation of the material.

Description

Line push-in butt connection of two structural components

The subject of the invention is a line push-in butt connection of two components, at least one of which is made of flexible plastic. The connection has a tongue and groove design and is used especially for detachable connection of parts of the insulation lagging of ventilation and air conditioning equipment.

In the technique of air exchange and treatment there are known solutions of air handling units, air conditioning units and recuperators equipped with shell laggings for acoustic and thermal insulation, made of foamed plastics. Foam shells are connected detachably - in the adhesion plane running along the diameters of the connection ports - by linear joints of the most often a tongue complementary with a groove, situated along or parallel to the edges of the shells of the parts being connected. The detachability of shells must be ensured for maintenance and repair purposes. For example, in the description of the FR2855251 invention, the connections are made along the edge as a complementary rectangular step, while according to the NL1016525 and GB2543909 descriptions the connections have a groove in the form of a rectangular keyway moved away from the outer edge of the shell to the adhesion plane. The known solutions are simple in technology, but without additional mechanical means of connection, which can cause thermal bridges and leaks, do not provide the required rigidity and tightness of the connection under conditions of differential pressure and vibrations initiated by the operation of fans.

The connection solution according to this invention, as described above, includes a groove and a tongue made in the plane of adhesion along the edges of the elements to be connected and which, after coaxial joining, complement each other in the axis of symmetry. The essence of the solution consists in the fact that the profile of the connection from the adhesion plane, determined by the groove, has, in order: a groove determined by the walls of a certain height, which at their closest point determine the smallest width of the groove, which at their lower ends connect, with bulges of a shape similar to a flattened letter“S” and its mirror image on the opposite bulge. In the upper section their convex shape is directed to the outside, forming the largest width to allow the bulge to be pressed into the groove without causing damage, within the range of elastic deformation of materials, while in the lower section, their convex shapes are directed to the inside of the connection and have the smallest width. Their lower ends are connected at the bottom of the groove, determining its height. While maintaining full similarity of the cross-sectional shape - the dimensions of the tongue corresponding to the said dimensions of the groove are different, which in combination forms at the height of the connection a loose fit with a gap or with a tight fit in the range of the elastic deformation of the material.

It is advantageous if, between the groove and the tongue, the gap and tight-fit zones occur in certain fragments of the bulges, which under the conditions of flexible materials initiates an axial clamping force, pressing the connected parts to each other. Due to the dimensional relationships in the shape of the mating surfaces of the groove and the tongue, a full understanding is possible after getting acquainted with the description of an embodiment of the connection, presented in the final content of the description.

Optionally, it may be advantageous to have the adhesion surface inclined at an angle to the axis of symmetry of the connection.

The adhesion surface may also be formed by two surfaces inclined towards each other and forming a profile of the letter“V” in the cross-section, situated in the axis of symmetry (S-S) of the connection.

The bottom of the groove and the bottom of the tongue may have a radial profile or form a straight line section.

It is also advantageous to make a connection in which a circular socket is made coaxially in the bottom of the groove, whose axis is located so that the upper part of the circle penetrates the profile of the tongue bottom. An elastic sealing cord with a circular cross-section, pressed by the bottom of the tongue, is inserted into the groove.

In the presented connection according to the invention, the special shape and differentiation of dimensions in the range causing elastic deformations of the material determines the stiffness of the connection under vibration conditions and at the same time the applied sealing cord supports the tightness of the connection.

In a preferred embodiment the walls of the groove are parallel to each other.

The connection according to the invention will be more easily understood from the description of an embodiment shown in the drawing, where Fig. 1 shows the cross-section of the connection while Fig.2 and Fig.3 respectively present the profile of the groove and the tongue with the dimensions relevant for the fitting marked thereon.

Made of foamed polypropylene, the upper A and lower B part of the air handling unit's insulation lagging, are connected in a detachable manner in the P-P adhesion plane by means of a line push-in butt connection, of the groove 1 and tongue 2 type. The connection profile described on the basis of the groove 1 cross- section (Fig. 2) is defined in order by: the keyway 1.1 of groove 1 with a height of hi and distance b1 between the walls, at the ends connected with left 1.2 and right 1.3 bulges, with a shape similar to flattened letter‘S’ and a mirror image on the opposite bulge. In the upper section, bulges 1 .2 and 1.3 are directed towards the outside so that at the depth of g1 they have the greatest width of s1 , while at the bottom they are directed towards the inside of the joint, so that at the distance i1 from the P-P adhesion plane they have the smallest width of j 1 , and at the lower ends they are connected with the arched bottom of groove 1 .4 with a chord of the width of u1 with the apex at a distance equal to the height H of the groove. For example, the embodiment of the connection had nominal dimensions: h=32 mm, b=14 mm, g=15 mm, s=19 mm, u=1 1 mm and d=7.5 mm. While maintaining full similarity of the cross-sectional shape - corresponding to the said nominal dimensions of the groove 1 , the dimensions of the tongue 2 marked as h2, b2, g2, s2, h, u2 and i2 and j2 in Fig.3 are different and in combination with the dimensions of tongue 2 they form at the height of the connection a loose fit with the gap“x” and“y” or a“w” and“z” tight fit in terms of elastic deformation of the foamed material. The fits with the“x” and“y” gaps between grove 1 and tongue 2 occur with uneven dimensions: H > h, j1 >=j2, M >=i2, while zones with“w” and“z” tight fit with: h 1 >h2, g1 >=g2, s2>=s1 , u2>u1

Full tightness of the connection is ensured by a flexible sealing cord 3, seated in a socket 1.5 made coaxially in the groove bottom 1.4. Socket 1 .5 with diameter“d” is located in such a way that the upper part of the circle penetrates into the profile of the arc of the tongue bottom 2.4 - which after pushing the tongue 2 into the groove 1 exerts pressure on the sealing cord 3. List of designations in the figure

A. Upper part of the lagging

B. Bottom part of the lagging

P-P. Adhesion plane

S-S. Axis of symmetry

1. Groove

1 .1 Keyway

1 .2 Left bulge

1 .3 Right bulge

1 .4 Groove bottom

1 .5 Socket

1 .6 Left bulge facing inwards

1 .7 Right bulge facing inwards

H. groove height

hi . key way height

b1 . keyway width

s1. the largest width between the bulges in the groove g1 . depth of the largest width between bulges

u1 . width of the groove bottom between the lower ends of the bulges

M . depth of the smallest width between bulges

j1. the smallest width between bulges

d. socket diameter

2. Tongue

2.1 Tongue shoulder

2.2 Left bulge

2.3 Right bulge

h. tongue height

h2. shoulder height

b2. shoulder width

s2. the largest width between the bulges of the tongue g2. depth of the largest width between bulges

u2. width of the tongue bottom between the lower ends of the bulges i2. depth of the smallest width between bulges

j2. the smallest width between bulges

2.4 Tongue bottom Sealing cord

x. the gap between the bottom of the groove and the bottom of the tongue

y. gap between groove and tongue

w. tight fit

Z. tight fit

Claims

Patent claims

1. Line push-in butt connection of two structural components, at least one of which is made of flexible plastic, especially for a detachable connection of parts (A, B) of the insulation housing of ventilation and air-conditioning equipment, containing a groove (1 ) and tongue (2), made in the adhesion plane (P-P) along the edges of the parts to be connected (A, B) and which, after a coaxial connection, have complementary shapes in the axis of symmetry (S-S), characterized in that the connection profile in order from the adhesion plane (P-P) is defined by a keyway (1.1 ) of the groove (1 ) of height (hi ) and the smallest width (b1 ) of the walls which at the ends connect with bulges (1 .2, 1 .3), having a shape similar to that of a flattened letter 'S' and its mirror image on the opposite bulge, and which at the top section are facing outwards, at a depth (g1 ) have the largest width (s1 ), making it possible to press the bulge (1.2) into the keyway (1.1 ) within the range of elastic deformation of the materials, while at the bottom the bulges (1.6, 1.7) are facing to the inside of the connection and at the depth of (i1 ) have the smallest width (j1 ) and their lower ends are connected at the bottom of the groove (1.4.) with a width of (u1 ) at the groove height (H), whereas, while maintaining complete similarity of the cross-sectional shape, corresponding to the aforementioned groove dimensions (1 ) the dimensions of the tongue (2) (h2, b2, g2, s2, h, u2, i2, j2) are different and, when combined, form at the height of the connection loose fits with a gap (x,y) or tight fits (w,z) within the range of elastic deformation of the material.

2. The connection according to claim 1 is characterized in that between the groove (1 ) and the tongue (2) there are zones with gaps (x, y), with the following dimensions: H > h, j1 >=j2, M >=i2, and tight-fit zones (w, z) with dimensions of g1 >=g2, hi > h2, u2>u1 , while maintaining z1 <u1.

3. The connection according to claim 1 or 2 is characterized in that the adhesion surface (P-P) is positioned at an angle to the axis of symmetry (S-S) of the connection.

4. The connection according to claim 1 or 2, characterized in that the adhesion surface (P-P), is formed by two surfaces forming a profile of the letter“V” in cross-section, placed in the axis of symmetry (S-S) of the connection.

5. The connection according to claim 1 or 2 characterized in that the bottom of the groove (1.4) and the bottom of the tongue (2.4) have a radial profile.

6. The connection according to claim 1 or 2, characterized in that the bottom of the groove (1.4) and the bottom of the tongue (2.4) have a straight line section profile.

7. The connection according to claims 1 or 5, or 6 characterized in that at the bottom of the groove (1 ) there is a coaxially made socket (1.5) with a diameter (d), the axis of which is located so that the upper part of the circle penetrates into the profile of the bottom of the tongue (2.4), with an elastic sealing cord (3) of circular cross-section embedded in the socket (1 .5).