GB1594911A - Protective and decorative moulding construction - Google Patents

Abstract

PROTECTIVE AND DECORATIVE MOLDING CONSTRUCTION A molding suitable for use as a decorative and protective trim for motor vehicles, comprising an elongated plastic body bendable to conform to external contours of a vehicle and containing therein a plurality of parallel, laterally spaced, longitudinally extending wires bonded to the plastic and formed of metal wire having a low modulus of elasticity and which is capable of stretching beyond its elastic limit to take a permanent set when the molding is bent in, or at an oblique angle with respect to, a common plane occupied by at least two of the wires, thereby stabilizing the overall bent shape of the molding.

Description

(54) PROTECTIVE AND DECORATIVE MOULDING CONSTRUCTION (71) We, THE STANDARD PRODUCTS COMPANY, a Corporation organised and existing under the laws of the State of Ohio, United States of America, of 2401 South Gulley Road, Dearborn, Michigan 48124, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a protective and decorative moulding construction which is bendable.

Mouldings of the type frequently referred to as "trim strips", which are secured to the sides and other areas of motor vehicles to provide ornamentation and protection against minor damage are, in modern practice, commonly formed of a plastics which possesses elastomeric properties and other characteristics rendering it superior to the metal formerly used. Such mouldings are normally formed of an extruded solid vinyl body, to which a chrome-like or other suitable ornamental surfacing may be applied. The plastics material employed in such mouldings intended for exterior installation, although elastomeric, is relatively.stiff, and where body contours might require its attachment in curved shapes, it frequently is not considered practical, and metal may be substituted. Since the plastics material is elastic, and has the "memory" which is characteristic of such plastics, it tends to return to its straight, extruded or initial form, and if it is installed on a curved surface, or is curved during installation, curved areas of the moulding may tend to separate fom the vehicle body. The metal mouldings which were commonly used before the development Qf high-quality plastics mouldings were normally preformed to desired contours by means of simple bending equipment prior to delivery to the body assembly line, the metal employed being of a character easily bendable beyond its elastic limit to the desired contouring so that it took a permanent set in the desired finished shape. Such treatment has not been feasible with plastics mouldings of the indicated character, as heretofore commonly constructed.

The overall objective of the present invention is to provide an improved moulding adapted for external use on motor vehicles and which comprises primarily a solid plastics body containing therein an arrangement of stiffening wires which are capable of being stretched lengthwise beyond their elastic limit when the moulding is bent, the arrangement being such that the distorted wires then effectively hold the moulding in its bent contour.

According to the present invention there is provided a bendable moulding including an elongated polyvinylchloride body having a durometer of 45 to 51 on the Shore D. scale, 15 second delay method, and having embedded therein a pair of spaced parallel metallic wires extending lengthwise therein, means being provided for securing said wires against longitudinal displacement with relation to the body, comprising a phenolic adhesive material coated onto the wires and to which the body is bonded, and the wires being formed of a material having a relatively low modulus of elasticity and capable of being stretched beyond the elastic limit thereof without fracturing when the body is bent in the common plane of said wires, whereby when the body is so bent, a radially outer wire is permanently elongated with relation to a radially inner wire and said wires thereafter oppose return of the moulding to its pre-bent shape.

With such an arrangement only a very small amount of metal need be incorporated, this metal being completely embedded in the plastics and effectively protected from corroding.

The invention will be further described, by way of example, with reference to the accompanying drawings, wherein: FIGURE I is a diagrammatic perspective view of a motor car provided with a moulding, or "trim strip", embodying the present invention; FIGURE 2 is a fragmentary elevational view, partly broken away, showing a portion of the moulding on a larger scale; FIGURE 3 is a cross-section of the moulding on a still larger scale; and FIGURE 4 is a view similar to Figure 3 showing a modification.

A motor vehicle generally designated V is diagrammatically illustrated in Figure I as provided with a decorative and protective moulding formed in three sections, a front section A secured to the front wing area, a mid-section B secured to the door of the vehicle as an aligned rearward continuation of section A, and a rear section C secured to the rear wing of the vehicle as a further aligned rearward continuation. Sections A and C include curved areas, respectively designated 11 and 12, which are bent upwardly in the plane of the moulding to extend arcuately around and outline the upper portions of the two wheel cut-out areas 13, 14.

As best shown in Figures 2 and 3, the moulding comprises an extruded body 10 formed of a polyvinylchloride having a durometer hardness of 48, plus or minus 3, on the Shore D scale, 15 second delay method. Although the specific configuration of the moulding may of course vary, it is shown as of modified T cross-section, having a central projecting rib or impact area 15. In such surface regions as may be desired for the sake of appearance, a chrome-like or other decorative coating may be applied to the outer surface of the body, as diagrammatically indicated at 17 and 18. An adhesive layer 16 is provided on the bottom surface of the body 10, by means of which the moulding is adapted to be secured to the surface of the vehicle body.

A pair of parallel wires 20, 21 extend longitudinally within and uninterruptedly throughout the length of the plastics body 10.

The wires are equidistant from the bottom surface and are spaced a substantial distance from each other. The wires are formed of a material having a low modulus of elasticity but substantial strength in compression, such as a mild steel, aluminium, or soft iron, and they are incorporated in the body 10 by extruding the plastics material around them.

The wires are initially coated with a phenolic adhesive material to cause the plastics material of the body 10 to bond thereto. In addition, the wires may be mechanically interlocked with the plastics as by being roughened or provided with fine ridges or indentations which are too shallow substantially to affect its physical properties but of sufficient depth to provide a mechanical interlock between the plastics and the wire.

The diameter, spacing, ductility and elastic modulus of the wires are such that when the moulding is bent in the common plane occupied by the wires 20 and 21, as is necessary in the case of the portions 11 and 12 which bound the wheel cut-out areas 13 and 14, the radially outer wire (the wire 20 in the illustrated instance) is stretched longitudinally beyond its elastic limit. Inasmuch as the radially inner wire (21 in the illustrated instance) is not compressible to any material degree by such bending of the moulding in the manner indicated, it will be appreciated that the outer wire 20 and the plastics material lying radially outwardly from the innermost wire 21 are stretched lengthwise.

Due to the low elastic modulus of the wire, the strain resulting from bending the moulding in the manner indicated causes a permanent elongation of the radially outer wire sufficient to correspond to the increased peripheral length required to maintain the desired curvature, the wire having been stressed beyond its elastic limit so that it takes a permanent set in the stretched condition. Thereafter, the wires strongly resist any tendency of the moulding to return to the straight initial form, the effort of the plastics to straighten being resisted by the reaction of the wire 20 to the longitudinal compression which is exerted upon it by the plastics, inasmuch as the wire 20 is highly resistant to axial compression, while the wire 21 is stressed in tension and thereby also resists restraightening of the moulding. The moulding accordingly preserves the contour imparted thereby by such bending in the plane of the wires.

Moulding sections such as the sections 11 and 12 illustrated in Figure 1, constructed as herein disclosed, can be preshaped, much as in the case of the metal trim strips formerly used in such applications, and can be applied to the vehicle body without requiring the workmen to attempt manually to shape the moulding or to restrain it from straightening during installation. As noted above, this has frequently been impractical to attempt with previous types of plastics mouldings. After attachment, any tendency of the bent moulding to distort or separate from the body is effectively prevented by reason of the fact that it is stabilised in the bent shape by the interaction of the stretched and unstretched wires 20 and 21.

The several variables which influence the ability of the moulding to retain its bent shape include the dimensions and configuration of the moulding, the physical characteristics of the plastics, the dimensions of the wires, the spacing of the wires, and the physical characteristics of the wires. Accordingly it is not feasible readily to derive a mathematical formula which will enable predicting positively whether plastics mouldings of various designs, with spaced wires therein, will retain their bent shape against the re-straightening effort of the plastics.

However, it has been found relatively easy empirically to construct such mouldings with parallel wires arranged as shown and described. The drawings illustrate in proper proportions a successful moulding which has been constructed. The body is formed of PVC of durometer 48, measured as indicated above. The wires are .031" diameter low carbon steel and bonded to the plastics by cementing as indicated above. The dimensions designated by small letters in Figure 3, in inches, are as follows: a = .650 b = .355 c = .260 d = .160 e = .27 f = .09 Such a moulding is readily bendable either by hand or on a bending machine, and will hold its bent shape.

Although "two" or "a pair" of wires have been referred to, it will be understood that while the described function is inherently accomplished by the spaced wires, two or more may be used.

In addition, as brought out in Figure 4, wherein parts corresponding to those of the first embodiment are designated by like reference numerals primed, one or more additional wires may be incorporated, located in different planes, to stabilise bent formations in different planes. The moulding 10' illustrated in Figure 4 is shown as constructed in the same way as the moulding of the first-described embodiment, except for the addition of a third wire 24 which is located on a central plane which is perpendicular to the base and at an outspaced position near the top of the impact rib 15'.

Since the wire 24 is on the centre plane, it does not interfere with bending the moulding in the plane of wires 20', 21', inasmuch as such bending applies no appreciable axial stress to the wire 24. However, if the moulding is bent in a plane at an angle to the common plane of wires 20', 21', an effect analogous to that already described occurs, the radially outer wire or wires being stretched and the radially inner wire or wires placed in compression. If the moulding is bent so as to bow its ends toward the back (and toward the vehicle body) as for example to conform to a convex surface, the wire 24 is stretched and wires 20', 21' placed in com pressicn.

In a further modification a fourth wire is added at the position shown in dotted lines at 25. The wires 24 and 25 will then, when the moulding is bent perpendicularly or at an angle to the back face (in or at an oblique angle to the plane of wires 24, 25), function similarly to the wires 20, 21 of the first embodiment.

WHAT WE CLAIM IS: 1. A bendable moulding including an elongated polyvinylchloride body having a durometer of 45 to 51 on the Shore D. scale, 15 second delay method and having embedded therein a pair of spaced parallel metallic wires extending lengthwise therein, means being provided for securing said wires against longitudinal displacement with relation to the body, comprising a phenolic adhesive material coated onto the wires and to which the body is bonded, the wires being formed of a material having a relatively low modulus of elasticity and capable of being stretched beyond the elastic limit thereof without fracturing when the body is bent in the common plane of said wires, whereby when the body is so bent, a radially outer wire is permanently elongated with relation to a radially inner wire and said wires thereafter oppose return of the moulding to its pre-bent shape.

2. A moulding as claimed in claim 1, which has a substantially planar bottom surface adapted to be secured to a supporting surface in contact therewith, the wires being substantially equidistant from said bottom surface and spaced from each other a distance which is a substantial proportion of the width of the moulding.

3. A moulding as claimed in claim 1 or 2, having a third wire in and also secured with respect to the body and parallel to the wires of said pair but spaced from the common plane occupied by the wires of said pair, said third wire also being formed of a material capable of being stretched beyond its elastic limit when the body is bent in a plane which is at an angle to said common plane.

4. A moulding as claimed in claim 1 or 2, including a second pair of wires parallel to the first pair and lying in a second common plane which intersects the common plane of the first pair of wires, the wires of said second pair also being secured with respect to the body and formed of a material capable of being stretched beyond its elastic limit when the body is bent in a plane which is at an angle to the common plane of the first pair of wires.

5. A moulding as claimed in any preceding claim, wherein a decorative coating is applied to at least part of the outer surface of the body.

6. A moulding constructed and arranged substantially as herein described with refer

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. physical characteristics of the wires. Accordingly it is not feasible readily to derive a mathematical formula which will enable predicting positively whether plastics mouldings of various designs, with spaced wires therein, will retain their bent shape against the re-straightening effort of the plastics. However, it has been found relatively easy empirically to construct such mouldings with parallel wires arranged as shown and described. The drawings illustrate in proper proportions a successful moulding which has been constructed. The body is formed of PVC of durometer 48, measured as indicated above. The wires are .031" diameter low carbon steel and bonded to the plastics by cementing as indicated above. The dimensions designated by small letters in Figure 3, in inches, are as follows: a = .650 b = .355 c = .260 d = .160 e = .27 f = .09 Such a moulding is readily bendable either by hand or on a bending machine, and will hold its bent shape. Although "two" or "a pair" of wires have been referred to, it will be understood that while the described function is inherently accomplished by the spaced wires, two or more may be used. In addition, as brought out in Figure 4, wherein parts corresponding to those of the first embodiment are designated by like reference numerals primed, one or more additional wires may be incorporated, located in different planes, to stabilise bent formations in different planes. The moulding 10' illustrated in Figure 4 is shown as constructed in the same way as the moulding of the first-described embodiment, except for the addition of a third wire 24 which is located on a central plane which is perpendicular to the base and at an outspaced position near the top of the impact rib 15'. Since the wire 24 is on the centre plane, it does not interfere with bending the moulding in the plane of wires 20', 21', inasmuch as such bending applies no appreciable axial stress to the wire 24. However, if the moulding is bent in a plane at an angle to the common plane of wires 20', 21', an effect analogous to that already described occurs, the radially outer wire or wires being stretched and the radially inner wire or wires placed in compression. If the moulding is bent so as to bow its ends toward the back (and toward the vehicle body) as for example to conform to a convex surface, the wire 24 is stretched and wires 20', 21' placed in com pressicn. In a further modification a fourth wire is added at the position shown in dotted lines at 25. The wires 24 and 25 will then, when the moulding is bent perpendicularly or at an angle to the back face (in or at an oblique angle to the plane of wires 24, 25), function similarly to the wires 20, 21 of the first embodiment. WHAT WE CLAIM IS:

1. A bendable moulding including an elongated polyvinylchloride body having a durometer of 45 to 51 on the Shore D. scale, 15 second delay method and having embedded therein a pair of spaced parallel metallic wires extending lengthwise therein, means being provided for securing said wires against longitudinal displacement with relation to the body, comprising a phenolic adhesive material coated onto the wires and to which the body is bonded, the wires being formed of a material having a relatively low modulus of elasticity and capable of being stretched beyond the elastic limit thereof without fracturing when the body is bent in the common plane of said wires, whereby when the body is so bent, a radially outer wire is permanently elongated with relation to a radially inner wire and said wires thereafter oppose return of the moulding to its pre-bent shape.

2. A moulding as claimed in claim 1, which has a substantially planar bottom surface adapted to be secured to a supporting surface in contact therewith, the wires being substantially equidistant from said bottom surface and spaced from each other a distance which is a substantial proportion of the width of the moulding.

3. A moulding as claimed in claim 1 or 2, having a third wire in and also secured with respect to the body and parallel to the wires of said pair but spaced from the common plane occupied by the wires of said pair, said third wire also being formed of a material capable of being stretched beyond its elastic limit when the body is bent in a plane which is at an angle to said common plane.

4. A moulding as claimed in claim 1 or 2, including a second pair of wires parallel to the first pair and lying in a second common plane which intersects the common plane of the first pair of wires, the wires of said second pair also being secured with respect to the body and formed of a material capable of being stretched beyond its elastic limit when the body is bent in a plane which is at an angle to the common plane of the first pair of wires.

5. A moulding as claimed in any preceding claim, wherein a decorative coating is applied to at least part of the outer surface of the body.

6. A moulding constructed and arranged substantially as herein described with refer

ence to or as illustrated in Figures 2 and 3 or Figure 4 of the accompanying drawings.