GB2136072A

GB2136072A - Drain rod

Info

Publication number: GB2136072A
Application number: GB08404651A
Authority: GB
Inventors: James William Peake
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-02-25
Filing date: 1984-02-22
Publication date: 1984-09-12
Also published as: GB2136072B; GB8404651D0

Abstract

A drain rod includes a rod 10 formed from flexible material ferrules 11 at the opposite ends of the rod, the ferrules each having deformed portions 12 conveniently of triangular shape with the apices directed towards the main body of the rod. The side edges 19 of the deformed portions merge smoothly into the remaining portion of the ferrule and the edges 18 of the deformed portions opposite the apices are sheared from the remaining portion of the ferrule. The base walls of the deformed portions incline downwardly to the edges. <IMAGE>

Description

SPECIFICATION Drain rod construction This invention relates to drain or like rods of the kind comprising a rod of flexible material such for example as polypropylene, and connector members including ferrules at the opposite ends respectively of the rod whereby a number of rods can be secured in end to end relationship.

In known drain rods the connector members each comprise a screw threaded member which is integrally formed or is secured relative to a hollow cylindrical member or ferrule which is located about the respective end of the flexible rod. It has been the practice to secure the ferrule to the flexible rod by means of a rivet which passes through aligned apertures in the ferrule and flexible rod. This method of connecting the ferrule to the flexible rod has proved to be particularly effective to withstand during the use of the rod, the forces tending to separate the ferrule from the flexible rod. The provision of the riveted connection does however add materially to the cost of the production of the drain rod.

Attempts have been made to secure the ferrule to the flexible rod by deforming tongues inwardly from the wall of the ferrule. The tongues in a known arrangement have extended in a longitudinal direction with the free ends of the tongues pointing in the direction away from the main body of the flexible rod. The idea behind the use of the tongues is that they will act in a similar manner to the barbs of a fish hook. It has been found that if an attempt is made to make the tongue wide, there is the possiblity of cracking of the material of the tongue at its root and if this occurs then the rod is useless and if it happens to occur while the rod is in use, the difficulty arises of retrieving a section of connected rods from the sewer pipe.

The object of the present invention is to provide a drain rod construction in a simple and convenient form.

According to the invention a drain or other rod of the kind specified is characterised in that a portion of the wall of the ferrule is deformed inwardly said deformed portion extending in the circumferential direction of the ferrule, the portion being concave intermediate its circumferential edges, the edges of said portion merging smoothly with the general contour of the exterior surface of the ferrule.

According to a still further feature of the invention the circumferentially extending edge of the deformed portion remote from the main body of the rod is sheared from the remaining portion of the ferrule.

In the accompanying drawings Figure 1 is a section along the line A-A of Figure 2 through one example of a drain rod in accordance with the invention.

Figure 2 is a longitudinal section on the line B-B of Figure 1.

Figure 3 is a plan view of another example of a drain rod in accordance with the invention, and Figure 4 is a section on the line C-C of Figure 3.

Referring to Figure 1 of the drawings the drain rod comprises a rod 10 formed from flexible material such as poZypropylene. The rod conveniently has a hole extending therethrough to economise on the amount of polypropylene necessary to form the rod and also to provide increased flexibility. At its opposite ends the rod is provided with a pair of screw threaded connector memebers respectively. These are not shown in the drawing but in a spigot having a peripheral screw thread and the other connector is of hollow form having an internal screw thread. The rods can be secured together by engaging the so-called male connector of one rod with the female connector of an adjacent rpd. The connector members are formed integrally with or are secured to hollow cylindrical members Qr ferrules 11.

These extend a short distance over the ends respectively of the flexible rod. The ferrules and the connector members may be formed from any convenient material such for example as brass or aluminium.

In order to secure the ferrules to the rods so that they can withstand the forces applied to the rods when they are in use, a portion of the wail of the ferrule is deformed inwardly. It is convenient to provide at least two such portions these being indicated generally at 12 in the drawing. The inward deformation of the portions 12 does cause deformation of the material forming the rod 10 and results in the creation of bulges indicated at 13 in the internal peripheral surface of the rod.

Each portion 12 is of strip like form and extends in the circumferential direction of the ferrule and each portion intermediate its ends, is of concave shape. The width in the axial direction, of each portion in the particular example, is approximately 8mm. The circumferential edges of the portions are arranged to merge smoothly with the surface of the ferrule so that no sharp ends occur such as might cause cracking of the material forming the ferrule.

The figure illustrates in outline only a tool 14 which can be utilised during the deformation of the portions 12. It will be noted that the tool at its end which is presented to the ferrule, has an intermediate profile 1 5 corresponding to the profile of the intermediate portion 12, and outer profiles 1 6 the curvature of which is substantially the same as the curvature of the outer surface of the ferrule. The tool is of blade like form having a width substantially equal to the width in the axial direction, of the deformed portion 1 2 and the action of the to5l is to shear the deformed portions 12 along their circumferentially extending edges, as clearly shown in the drawing.

It is convenient to form the deformed portions at the same time so that two tools as shown at 14 would be provided, one of which would be fixed to the bolster of a press, the other tool being fixed to the moving part of the press. The action of shearing the deformed portions does tend to produce local deformation of the material forming the ferrule, such local deformation being shown in Figure 2.

It is preferable for the portion 12 to be continuous. However, it has been found when aluminium is used that the portion 12 can be allowed to crack at its midpoint during formation provided that at the end of the forming operation the two edges are so close that any relative angular movement of the flexible rod and ferrule will cause the edges to move into contact with each other.

With reference now to Figures 3 and 4 the portions 12 are of generally triangular shape with the apex 17 of each portion being directed towards the main body of the rod. The base edges 1 8 of the portions are sheared from the main wall of the ferrule and these edges bite into the material forming the rod. These edges resist the axial force applied in use between the rod and the ferrule and which would tend to detach the rod from the ferrule. The forces applied to the edge are applied to the portion 1 6 and distributed into the main wall of the ferrule.This smooth distribution of the forces is assisted by the fact that the inclined side edges 1 9 of the portions merge smoothly with the adjacent surface of the ferrule so that no sharp edges occur which might cause during manufacture, or in the use of the rod, cracking of the material from which the ferrule is formed. Intermediate the side edges 19 the portion is of concave form and the base wall of the portion slopes downwardly or inwardly towards the edge 18, from the apex. As with the example shown in Figures 1 and 2 the action of shearing the edges 18 and forming the concave shape does tend to cause local deformation of the material forming the ferrule.

The tools which are used to form the portions of the example of Figures 3 and 4 are themselves of generally triangular section but are shaped towards the edge of the tool which causes the shearing action, in a manner complementary to the base wall of the deformed portions.

Claims

1. A drain or like rod comprising a rod of flexible material such for example as polypropylene, and connector members including ferrules at the opposite ends of the rod respectively whereby a number of rods can be secured in end to end relationship, characterised in that a portion of the wall of the ferrule is deformed inwardly, said deformed portion extending in the circumferential direction of the ferrule, the portion being concave intermediate its circumferential edges, the edges of said portion merging smoothly with the general contour of the exterior surface of the ferrule.

2. A drain or like rod according to Claim 1 in which the circumferentially extending edge of the deformed portion remote from the main body of the rod is sheared from the remaining portion of the ferrule.

3. A drain or like rod according to Claim 2 in which the deformed portion is of generally triangular shape with the apex of the deformed portion being directed towards the main body of the rod.

4. A drain or like rod according to Claim 3 in which the base walls of said deformed portions incline downwardly toward said circumferentially extending edge.

5. A drain or like rod according to Claim 2 in which said deformed portions are of strip like form the other circumferentially extending edges of said deformed portions also being sheared from the remaining portion of the ferrule.

6. A drain or like rod according to any one of the preceding claims in which the rod is of hollow form and the action of deforming said portions produces deformation of the internal surface of the rod.

7. A drain or like rod comprising the combination and arrangement of parts substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.

8. A drain or like rod comprising the combination and arrangement of parts substantially as hereinbefore described with reference to Figures 3 and 4 of the accompanying drawings.