GB2216589A

GB2216589A - Plastics binding strap

Info

Publication number: GB2216589A
Application number: GB8904493A
Authority: GB
Inventors: Willibald Kraus
Original assignee: TRW United Carr GmbH and Co
Current assignee: TRW United Carr GmbH and Co
Priority date: 1988-03-04
Filing date: 1989-02-28
Publication date: 1989-10-11
Anticipated expiration: 2009-02-28
Also published as: NL8900511A; FR2628072A1; GB8904493D0; GB2216589B; SE504266C2; FR2628072B1; SE8900345D0; DE3807173C2; DE3807173A1; SE8900345L

Description

2'z 1 8 9 PLASTICS BINDING STRAP The invention relates to a plastics

binding strap which may be used f or clasping, holding and bundling objects.

US Patent Specification 3590442 discloses such a strap having a profiled band part with longitudinal webs and rungs and, - connected to it, a head part which, within a passage opening, has an obliquely extending sprung locking element, or detent, for interacting with the prof ile of the strap part andopposite to the locking element - a smooth contact surf ace for the region of the band part enclosed in the head part in the locked position, the f ront part of the locking element being in contact, in the locked position, with a rung of the band part and the latter being pressed against the smooth contact surface of the passage opening of the head part. The strap is designed in such a way that the locking element has a uniform width whereas the passage opening for the passage of the band part is designed in two sections of different widths. The band part is therefore guided on the outer regions of its longitudinal webs. The consequence is a relatively complicated construction in the arrangement of the head part and this leads ultimately to the overall design being 2 expensive.

Also known from US Patent Specification No. 3488813 is a binding strap whose locking element consists of a steel tongue which is embedded in the band part in the locked position. This design is also expensive because, in this case, it is necessary to introduce the steel tongue into the band part which consists of plastic.

Also known from DE-C-2328955 is a binding strap which is designed in such a way that the head part consists of three passages, i.e. a central passage in which the band part slides, an upper passage in which the front part of the locking element can engage and a lower passage which is intended to accept the locking element during assembly. US Patent Specification 4001898 discloses a binding strap in which one locking element is opposite to a hook-shaped holding element within the head part so that the individual rungs of the strap part must be fed between both elements during assembly.

The above-mentioned straps have complex designs and/or give rise to substantial assembly costs when used.

An object of the invention is to provide a binding strap with a substantially simpler construction which can be readily fastened and which 3 nevertheless is releasable when fastened.

The invention provides a plastics binding strap having a band part provided with a plurality of apertures or recesses spaced apart therealong between. opposed edge portions thereof and a head part at one end of the band part, said head part having a through- opening through which the other end of the band part is insertable, which through-opening includes smooth surface means for contacting the portion of the band part disposed within the through-opening when the band part is inserted through the through-opening, said head part being provided with a resiliently deflectable detent extending obliquely across said through-opening towards said smooth surface, which detent has a stepped configuration comprising a first step portion projecting towards said smooth surface from a second step portion, the first step portion being adapted to locate within a said aperture or recess of said band part and the second step portion having respective surfaces for engaging the edge portions of the band part and urging those edge portions towards or against the smooth surface means of the through- opening.

The said surf aces of the second step may be substantially parallel to said smooth surface means of the through-opening, in which case said. surf aces of 4 the second step may merge into respective concavely curved end surfaces thereof.

The detent may be provided with a projection which extends out of the through-passage to enable said detent to be deflected to move said first step portion out of a said aperture or recess of the band part to enable the band part to be withdrawn from said through-opening.

The detent may have a third step portion which is connected to the second step portion and to the head portion at a further surface of the throughopening thereof opposite said smooth surface thereof. When such a third step portion is provided, the first and third step portions may be of substantially the same width. Furthermore, the first step portion may merge into the third step portion, the second step portion being spaced apart from the further surface of the through-opening.

Preferably, the band part has two spaced apart longitudinally extending side members interconnected by a plurality of longitudinally 'spaced apart crosspieces, said side members forming said edge portions of theband part and the apertures or recesses thereof being defined between said side members and adjacent cross-pieces. A web may extend between the side members on that side of the band part which contacts said smooth surf ace of the through-opening when the band part is inserted therethrough. In this case, it will be appreciated that the band part is provided with spaced apart recesses rather than through5 apertures.

Preferably at least the surfaces of the crosspieces which face the detent when the band part is inserted through the through-opening are convexly curved and the end of the f irst step portion of the detent is correspondingly concavely curved.

In one embodiment of the invention a plastics strap for clasping, holding and bundling objects, has a profiled band part with longitudinal side members and rungs and, connected to it, a head part which, within a passage opening, has an obliquely extending sprung locking element for interacting with the profile of the band part and - opposite to the locking element - a smooth contact surface for the region of the band part enclosed in the head part in the locked position, the front part of the locking element being in contact, in the locked position, with a rung of the band part and the latter being pressed against the smooth contact surface of the passage opening of the head part, wherein the locking element is provided with steps adapted to cooperate with the band part, an outer first step forming the front 6 region of the locking element being enclosed, in the locked position of the band part, between the longitudinal side members, and the longitudinal side members being each guided in the longitudinal direction on flat surfaces respectively on the adjacent second step. This provides the advantage that the design of the head part is substantially simpler than the head parts of the straps disclosed in the above- mentioned prior art specifications, the locking element undertaking a double function, i.e. the locking and guidance of the band part during assembly and in the locked position.

In a further embodiment of the invention, the flat surfaces of the second step of the locking element can extend parallel to the smooth contact surface of the passage opening of the head part so that the band part is well guided in the head part, both during assembly and in the locked position.

In addition, individual steps can have different widths.

In order to facilitate dismantling, i.e. the withdrawal of the band part from the head part, in one embodiment a so-called grip strip is provided on the second step and protrudes from the head part, for pivoting the locking element away from the locked position. If this grip strip is pulled, the locking 7 element is pivoted away f rom its locked position and therefore releases the band part, which can be withdrawn from the head part.

In a f urther embodiment a third step of the locking element is connected to the second step, the third step merging into a surface of the passage opening opposite to the smooth contact surface of the head part. The f irst and third steps can have the same width, it being possible for the first step to merge into the third step and f or the second step to be located in the region of an undercut of the locking element. This again provides a simple arrangement of the head part and the locking element.

It is also possible for the end surface of the first step to have an arch-shape corresponding to the shape of the rung so that there is a very good holding function in the locked position of the locking element relative to the band part.

In a further embodiment the band part can be provided with a web between its longitudinal side members and rungs such that in the locked position, the back of this web is in contact with the smooth contact surface of the passage opening of the head part. This design of the band part provides, in a simple manner, an increase in strength.

In order that the invention may be well 8 understood, the above-mentioned embodiments, which are given by way of example only, will now be described, with reference to the accompanying drawings, in which:

Fig. 1 is a fragmentary plan view of a binders strap; having a head part and band part; Fig. 2 is a section along the line II-II in Fig. 1; Fig. 3 is a fragmentary plan view of the same strap with the band part inserted into the head part and shown in cross-section; Fig. 4 is a section along the line IV-IV in Fig.

3; Fig 5 is a fragmentary plan view of another binder strap having a head part and a band part; Fig. 6 is a section along the line VI-VI in Fig.

5; Fig. 7 is a section similar to Fig. 6 of another binder strap showing the band part thereof inserted in the head part; and Fig. 8 is a fragmentary sectional view of an alternative configuration for the band part of the binder straps.

In Fig. 1 and 2, the plastics binding strap has a profiled band part 1 with longitudinally extending side members 2 and 3 interconnected by a plurality of longitudinally spaced apart cross-pieces, or rungs, 4 9 to provide the band part with a plurality of apertures. This band part 1 merges into a head part 5 which has, within a through-opening, or passage, 6, an obliquely extending, resiliently def lectable locking element, or detent 7, for interacting with the profile of the band part 1. A smooth contact surf ace 8 is located opposite to this locking element 7 in the through passage 6.

The locking element 7 has a stepped configuration, being provided with a first step 9 which merges into a second step 10. Surfaces 12 and 13 are formed between the first step 9 and the second step 10 by this means.

In the rear region of the locking element 7, there is an undercut 16 which merges into a surface 15 opposite to the contact surface 8 of the passage 6. Thus the second step 10 is spaced apart from the surface 15. In its front region, the first step has a concavely curved arch-shape 22 which is matched to the convexly curved shape of the rung 4 of the band part 1.

As may be seen f rom Fig. 2, the height H of the outer first step 9 may be smaller than the thickness B of a rung 4 of the band part 1. It is, however, also possible for the height H to be equal to or larger than the width B of a rung when the band part is provi-ded wi_th apertures as 111ustrated whereby -good adaptation to the desired holding effect is advantageously provided.

For assembly, the band part is inserted in the direction of arrow I into the head part 5, the individual rungs 4 of the strap part 1 pressing the locking element 7 against the surface 15 and this continuing until the locking procedure has been concluded.

Figs. 3 and 4 show how the side members 2 and 3 and the rungs 4 of the strap part 1 are located in the head part 5. As will be seen, the outer step 9 of the locking element 7 is located, in a locked position of the band part, between the longitudinal side members 2 and 3, the longitudinal side members 2 and 3 being guided in longitudinal direction on the adjacent second step 10 on the flat surfaces 12 and 13. If, as shown in Fig. 4, tension is applied to the band part 1 in the direction of arrow II, the corresponding rung 4 engages in the arch-shape 22 of the first step 9 so that very good locking is ensured in a simple manner. The left-hand side of the longitudinal side members 2 and 3 (as viewed in Figs. 3 and 4) are then in contact with the smooth contact surface 8 of the opening 6 of the head part 5.

In the embodiment of Fig. 1 and 2, the locking element 7 is provided with two steps 9 and 10. In the embodiment of Figs. 5 and 6, the locking element 71 has three steps, i.e. a first step 9. a second step 10 and a third step 11. Here again, the height H of the f irst step 9 can be matched to the thickness B of a rung of the strap part.

In the embodiment of Figs. 5 and 6, the first and third steps 9 and 11 have,, in addition, the same width, and the first step merges into the third step with the second step 11 being in the region of the undercut 16 of the locking element 7. In a manner analogous to the design of Figs. 1 and 2, there are again surfaces 12 and 13, in the region of the second step, on which the longitudinal side members 2 and 3 of the strap part 1 are guided, in a manner analogous to the assembly of Fig. 3. Convexly curved arched surfaces 18 continue from these surfaces 12 and 13, as shown in Fig. 6.

In this design also, the end surface of the first step 9 has an arch-shape 22 corresponding to the shape of the rung 4 so that, after assembly is completed, a situation arises analogous to that of Fig. 4.

In Fig. 7, the locking element 711 is arranged in such a way that, in a manner analogous to the design of Figs. 1 and 2, there is again a first step 9 and a second step 10. Connected to the second step 10, 12 there is then a projection, or so-called grip strip, 14, protruding from the head part 5, for pivoting the locking element 71, away from the locked position. If this grip strip 14 is pulled in the arrow direction 111, the locking element 711 pivots against the surface and therefore releases the band part 1 within the head part since the f irst step 9 moves out of the region between the two longitudinal side members 2 and 3. By this meansr the band part 1 can be withdrawn from the head part 5 because the locking element 711 no longer acts as a catch.

In all the embodiments thus far described, the band part is designed in the form of two longitudinal side members 2 and 3 with rungs 4 there being through openings, or apertures, between the rungs 4 and the longitudinal side members 2 and 3. In the embodiment of Fig. 8, the band part 11 is provided with a web 20 extending between the side members 2 and 3 on that side of the band part which contacts the surface 8 of the through opening 6 of the head part 4 1. In the locked position, the back 21 of the web 20 is arranged for contact with the surface 8. This, on the one hand, provides good guidance for the band part 1 1 during assembly and dismantling and, on the other, provides increased strength to the overall design. As will be appreciated the web 20 closes the apertures in 13 the band part which would otherwise be present and thereby defines a plurality of recesses with the side members 2, 3 and rungs 4.

In each embodiment, the 'locking element for the strap embodiment is f ormed in such a way that, in addition to simple construction, accurate matching is provided, by a multiplicity of steps, to the shape of the band part with its.longitudinal side members 2 and 3 and its rungs 4 so that the strap securely binds the 10 objects it embraces when in a locked condition.

These objects can, for example, be cables in a motor vehicle or tubes. This is particularly important in the field of motor vehicle technology where rapid.. simple and secure assembly is required at the least possible cost.

Claims

14 CLAIMS:

1. A plastics binding strap having a band part provided with a plurality of apertures or recesses spaced apart therealong between opposed edge portions thereof and a head part at one end of the band part, said head part having a through-opening through which the other end of the band part is insertable, which through-opening includes smooth surface means for contacting the portion of the band part disposed within the through-opening when the band part is inserted through the through-opening, said head part being provided with a resiliently deflectable detent extending obliquely across said through-opening towards said smooth surface, which detent has a stepped configuration comprising a first step portion projecting towards said smooth surface from a second step portion, the first step portion being adapted to locate within a said aperture or recess of said band part and the second step portion having respective surfaces for engaging the edge portions of the band part-and urging those edge portions towards or against the smooth surface means of the through- opening.

2. A strap as claimed in claim 1 wherein said surfaces of the second step are substantially parallel to said smooth surface means of the through-opening.

3. A strap as claimed in claim 2, wherein said surfaces of the second step merge into respective concavely curved end surfaces thereof.

4. A strap as claimed in claims 1, 2 or 3- wherein said detent is provided with a projection which extends out of the through-passage to enable said detent to be deflected to move said first step portion out of a said aperture or recess of the band part to enable the band part to be withdrawn from said through-opening.

5. A strap as claimed in any one of claims 1 to 4, wherein the detent has a third step portion which is connected to the second step portion and to the head portion at a further surface of the through- opening thereof opposite said smooth surface thereof.

6. A strap as claimed in claim 5, wherein the first and third step portions are of substantially the same width.

7. A strap as claimed in claim 5 or 6, wherein the first step portion merges into the third step portion, and the second step portion is spaced apart from said further surface of the through- opening.

8. A strap as claimed in any of the preceding claims, wherein said band part has two spaced apart longitudinally extending side members interconnected by a plurality of longitudinally spaced apart cross- 16 pieces, said side members forming said edge portions of the band part and the apertures or recesses thereof being defined between said side members and adjacent cross-pieces.

9. A strap as claimed in claim 8, wherein a web extends between the side members on that side of the band part which contacts said smooth surface of the through-opening when the band part is inserted therethrough.

10. A strap as claimed in claims 8 or 9 wherein at least the surfaces of the cross-pieces which face the detent when the band part is inserted through the through-opening are convexly curved and the end of the first step portion of the detent is correspondingly concavely curved.

11. A plastics strap for clasping, holding and bundling objects, having a profiled band part with longitudinal side members and rungs and, connected to it, a head part which, within a passage opening, has an obliquely extending sprung locking element for interacting with the profile of the band part andopposite to the locking element - a smooth contact surface-for the region of the band part enclosed in the head part in the locked position, the front part of the locking element being in contact, in the locked position, with a rung of the band part and the latter 17 being pressed against the smooth contact surface of the passage opening of the head part, wherein the locking element is provided with steps adapted to cooperate with the band part, an outer first step forming the front region of the locking element being enclosed, in the locked position of the band part, between the longitudinal side members, and the longitudinal side members being each guided in the longitudinal direction on flat surfaces respectively on the adjacent second step.

12. A strap according to claim 11, wherein the flat surfaces of the second step of the locking element extend parallel to the smooth contact surface of the passage opening of the head part.

13. A strap according to claim 12 wherein the flat surfaces of the second step each merge into An arched end surface.

14. A strap according to claim 11, 12 or 13 wherein the individual steps have different widths.

15. A strap according to any one of claims 11 to 14, wherein on the second step, a grip strip protruding from the head part is provided for pivoting the locking element against the locked position.

16. A strap according to any one of claims 11 to 15,, wherein the second step is connected to a third step of the locking element, which third step merges 18 into a surface of the passage opening opposite to the smooth contact surface of the head part.

17. A strap according to claim 16, wherein the first and third steps have the same width.

18. A strap according to claim 17,, wherein the first step merges into the third step and the second step is located in the region of an undercut of the locking element.

19. A strap according to any one of claims 11 to 18 wherein the band part between its side members and rungs is provided with a web whose back, in the locked position, is in contact with the smooth contact surface of the passage opening of the head part.

20. A strap according to any one of claims 11 to 19, wherein the- end surface of the first step is an arch-shape corresponding to the shape of the rung.

21. A- plastics strap substantially as hereinbefore described with reference to Figures 1 to 4, 5 and 6.. 7 of the accompanying drawings or those figures when modified by Figure 8 of the accompany drawings.

Published 1989 at The Patent OMce, State House, 68.171 High Holborn, London WClR4TP. Further copies maybe obtained from The Patent Ofnce. Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent, Con, 1187