BUNDLE TIE
The present invention generally relates to a fasten¬ ing element which is intended to keep objects, such as wire bundles, together. To be more specific, the inven¬ tion concerns a bundle tie comprising an elongate band member having a width exceeding its thickness, an elon¬ gate insertion member which is connected to one end of the band member and has a smaller width than the band member, a locking head which is connected to the other end of the band member and which has not only a through- going opening extending substantially transversely of the band member closest to the locking head and being adapted to receive a portion of the band member, but also a slit extending in the longitudinal direction of said opening from the latter to the outside of the locking head and being adapted for the insertion of a portion of the insertion member into the throughgoing opening prepara¬ tory to pulling the band member into this opening, and cooperating locking teeth arranged on the band member and in the throughgoing opening. SE 367,803 teaches a bundle tie of the above type. However, the locking head of this bundle tie is far from fulfilling the two requirements that have to be placed on the locking head proper, namely that it should be easy and expedient to pull the band member through the opening in the locking head and that the band member should be protected from being pulled out of the opening once it has been fastened. In the prior-art bundle tie, the first requirement is met by imparting a certain resilience to the claw-shaped elements delimiting the opening and the slit in the locking head. This resilience does, however, adversely affect protection against the band member being pulled out after fastening.
Furthermore, US 3,837,047 discloses another bundle tie, whose opening however extends in parallel with the
band member adjacent to the locking head. As a result, one cannot, when inserting the band member in the locking head, hold the band member but one has to hold the lock¬ ing head, which renders mounting more difficult and, hence, excessively time-consuming.
However, the bundle ties available on today's market are usually provided with a closed locking head, such that the band member has to be run through the locking head in the way a needle is threaded. It goes without saying that this is a time-consuming operation, even if the locking head is angled so that the opening therein extends transversely of the band member closest to the locking head.
The object of this invention is to obviate the draw- backs of the prior-art bundle ties by providing a bundle tie which is of the type described by way of introduction and which further can be manufactured in an injection moulding machine of simplified design, by which is meant such a machine as can be opened in one direction without any separate back movements for releasing the injection- moulded component.
According to the invention, the above object is attained by a bundle tie which is characterised in that the locking head is formed with a throughhole in the lon- gitudinal direction of the opening and on a side of the opening that is opposite to the slit, and that a bridge formed between said hole and said opening is resiliently connected to opposite longitudinal sides of the locking head. Owing to the inventive provision of the hole and the bridge, the above-mentioned two requirements placed on the locking head are met. To be more specific, this is achieved as a result of the bridge imparting the requir¬ ed yieldingness enabling the band member to be easily and expediently pulled into the opening, while at the same time increasing the stiffness of the claw-like portions otherwise delimiting the opening and the slit. Further-
3 more, the inventive design of the locking head enables the bundle tie according to the invention to be manufac¬ tured with the aid of injection moulding machines of the simplified design described above. It goes without saying that the manufacture of the bundle tie is thus simplified as well as rendered less expensive.
The resilient bridge may, along its entire length, be connected to the remainder of the locking head. Alter¬ natively, the bridge may be connected to the remainder of the locking head along but part of its length, for instance by means of a pin. Preferably, the band member of the bundle tie is of U-shaped cross-section, having a web determining the width of the band member, as well as flanges determining the thickness of the band member. On the side facing away from the bridge, the throughgoing opening in the locking head has projecting portions cor¬ responding to the free flanges of the band member. As a result of this design, the claw-like portions delimiting the throughgoing opening and the slit are prevented from being displaced away from each other, which further en¬ sures the retention of the band member in the through- going opening after fastening of the bundle tie.
In one embodiment of the bundle tie according to the invention, the cooperating locking teeth arranged on the band member and in the throughgoing opening may be dis¬ posed on the web of the band member between the flanges thereof, as well as in the throughgoing opening between the portions corresponding to the free flanges of the band member. Yet another object of the invention is to enable expedient dismounting of the bundle tie when need be.
In the bundle tie according to the invention, this is achieved by the locking head, in the throughgoing opening for receiving the band member, having locking teeth arranged on the bridge to cooperate with the lock¬ ing teeth of the band member after the band member has been inserted in the throughgoing opening with the free
ends of the flanges facing the bridge. Naturally, the locking teeth on the bridge should be directed opposite to the locking teeth between the portions corresponding to the free flanges of the band member. In this case, the expedient dismounting is made possible by bevelling the band member externally at the longitudinal edges between the flanges and the web. However, secure locking can be achieved with the aid of a separate sealing pin, which can be introduced into the hole in order to prevent the bridge from moving resiliently in the direction away from the slit. Of course, this sealing pin can be used regard¬ less of the direction of insertion of the band member into the opening.
The invention will now be described in more detail with reference to the accompanying drawings, in which
Fig. 1 is a schematic plan view of an embodiment of the bundle tie according to the invention,
Fig. 2 is a side view of the bundle tie of Fig. 1 when in closed position, Fig. 3 is a cross-section taken along line III-III in Fig. 1, showing a band member of the bundle tie,
Fig. 4 is a longitudinal section taken along line IV-IV in Fig. 1, showing the band member of the bundle tie, Fig. 5 is a cross-section taken along line V-V in Fig. 1, showing a locking head of the bundle tie,
Fig. 6 is a cross-section similar to Fig. 5, showing an alternative design of the locking head, and
Figs 7 and 8 are larger-scale views of the locking head in Fig. 1, showing the inserted band member in two different positions.
Thus, Fig. 1 illustrates a bundle tie 1 comprising a band member 2 which has a width exceeding its thickness, as appears from Fig. 3. Furthermore, the bundle tie 1 comprises an elongate insertion member 3 which is con¬ nected to one end of the band member 2 and which has a smaller width than the band member 2. Finally, the bundle
tie 1 includes a locking head 4 connected to the other end of the band member 2. This locking head 4 is formed with a throughgoing opening 5, which extends essentially transversely of the band member 2 closest to the locking head 4 and is adapted to receive a portion of the band member 2. Moreover, the locking head 4 has a slit 6 which extends in the longitudinal direction of the opening 5 from the latter to the outside of the locking head 4 and is adapted for the insertion of a portion of the inser- tion member 3 into the throughgoing opening 5 preparatory to the band member 2 being pulled into this opening 5.
In accordance with the invention, the locking head 4 further has a throughhole 7 extending in the same direc¬ tion through the locking head 4 as the opening 5, more specifically on that side of the opening 5 which is oppo¬ site to the slit 6. There is thus formed a bridge 8, which is resiliently connected to opposite longitudinal sides 9, 10 of the locking head 4 by means of strips 11, 12 formed integral with the bridge 8. As shown in Fig. 5, the strips 11, 12 extend along the entire length of the bridge. Alternatively, the bridge 8 may, as shown in Fig. 6, be connected to the longitudinal sides 9, 10 of the locking head along but part of its length, for in¬ stance by means of a pin 13 which extends perpendicularly to the longitudinal direction of the opening 5 and about which the bridge 8 is resilient through torsion.
As illustrated in Fig. 3, the band member 2 is of U-shaped cross-section, having a web 14 determining the width of the band member 2, as well as flanges 15, 16 determining the thickness of the band member 2. On the web 14 between the flanges 15, 16, the band member 2 is provided with locking teeth 17, as is shown most clearly in Fig. 4.
The throughgoing opening 5 for receiving the band member 2 has portions 18, 19 projecting from the side facing away from the bridge 8 and corresponding to the free flanges 15, 16 of the band member 2. Also, locking
teeth 20, 21 are provided in the throughgoing opening 5 between the portions 18, 20 as well as on each side of the slit 6. Thus, the longitudinal sides 9, 10 of the locking head 4 constitute claw-shaped portions kept together by the bridge 8.
Fig. 7 illustrates in more detail the position of the band member 2 in the locking head 4 when the band member 2 has been pulled into the locking head 4 in the direction indicated by dashed lines in Fig. 2. To be more specific, the locking teeth 17 of the band member 2 here engage the locking teeth 20, 21 of the locking head 4, while at the same time the free ends of the band-member flanges 15, 16 engage the portions 18, 19. Finally, the web portion of the band member 2 rests on the upper side of the bridge 8, such that the band member 2 occupies a perfectly fixed position in the opening 5 of the locking head 4.
To be more specific, the band member 2 may be ap¬ plied against a row of locking teeth 22 on the side of the bridge 8 facing the slit 6. The purpose of the lock¬ ing teeth 22 will be explained in more detail below with reference to Fig. 8.
Thus, Fig. 8 shows the locking head 4, the band mem¬ ber 2 being inserted in the opening 5 in the direction indicated by full lines in Fig. 2. Thus, the free ends of the flanges 15, 16 will be applied against the strips 11, 12, and the locking teeth 17 of the band member 2 will engage the locking teeth 22 on the bridge 8. The web 14 of the band member 2 will at least partly be applied against the locking teeth 20, 21. As illustrated in
Fig. 8, the band member 2 is, furthermore, externally bevelled at the longitudinal edges between the flanges 15, 16 and the web 14. As a result, the bundle tie 1 can be expediently dismounted. More specifically, the band member 2 is rotated in the opening 5 while the claw-shap¬ ed portions 9, 10 are bent outwards, whereupon the band
member 2 can be lifted up through the slit 6, the bundle tie having thus been dismounted.
In order to prevent the band member 2 from being released from the locking head 4 when the bundle tie is mounted as shown in Fig. 8, a sealing pin 23 may, as shown in Fig. 6, be introduced into the hole 7 and be fixed therein. As appears from Fig. 5, the fixing pin 23 is formed integral with the locking head 4. Naturally, the sealing pin 23 may also be used to further secure the bundle tie in fastened position in accordance with Fig. 7.
As appears from Figs 5 and 6, but a few locking teeth 20-22 are required on the locking head 4, prefer¬ ably 1-4 teeth. Furthermore, the locking teeth 22 are spaced apart from the locking teeth 20, 21 in the longi¬ tudinal direction of the opening 5, thereby to facilitate the operation of pulling the band member 2 into the open¬ ing 5.
It goes without saying that several modifications of the above embodiments of the bundle tie according to the invention are conceivable within the scope of the inven¬ tion, as defined by the appended claims.