Locking arrangement for safety belt
Technical field
The present invention relates to a locking arrangement for a safety belt, according to the preamble to Patent Claim 1.
Prior art
In motor vehicles, it has long been customary for protective purposes to use safety belts of the three-point type on vehicle seats. In this case, the safety belt runs, on the one hand, diagonally across the chest and, on the other hand, transversely over the hip region of the belt user and is locked or released using a locking device on one side of the seat.
It has proved desirable, however, to achieve a better protective function by securing the belt user with a further diagonally fitted safety belt, running over the previously free shoulder of the user. There is a problem in this connection, however, that such a solution calls for two belt locks to be operated, one on each side of the belt user. In the application of the belt it is acceptable to need to operate two belt locks, yet from a safety and comfort perspective it is desirable to be able to uncouple such double belts quickly using a single manoeuvre and a single release mechanism which will work in all situations. There is therefore a need for a simple and reliable solution in this regard.
Purpose of the invention
The object of the invention is to produce a locking arrangement which is designed for two safety belts and has reliable performance and is comfortable in use. Another object is to ensure that a three-point belt is applied before a two- point belt can be applied, this to eliminate the risk of only the two-point belt being used and hence of providing worse protection than normal. Yet another object is to achieve high functional reliability and simplicity of construction.
Disclosure of the invention
The object of the invention is achieved by means of a locking arrangement having the characteristics stated in Patent Claim 1.
By using two mutually mechanically connected locking devices of somewhat modified standard type, in which operation of the locking device for the three- point belt releases both locking devices simultaneously, a simple, secure and rapid release of both safety belts at once is achieved. By further linking the locking devices in such a way that the locking device for the two-point belt is held in open position as long as the three-point belt is not applied, a coercion is easily obtained to attach the three-point belt before the two-point belt can be attached. This makes it impossible to apply the two-point belt in advance of the three-point belt.
The two locking devices can advantageously be linked using a simple wire device in which a wire is displaceable within a sleeve, one end of the wire being coupled to the ejector for a locking tongue on the locking device of the three- point belt, whilst the opposite end of the wire is coupled to a control part on the locking device of the two-point belt. This is arranged such that when the said ejector is in an upper ejection position, the said control part is in a lower release position. A wire device of this type can easily be fitted to a particular seat such that it does not cause disturbance.
Further characteristics and advantages of the invention can be derived from the following description and remaining patent claims.
The invention is explained in greater detail below with reference to an illustrative embodiment shown in the appended drawing.
Description of figures
In the drawing:
Fig. 1 shows a front view of a vehicle seat having a locking arrangement according to the invention for a double-type safety belt, Fig. 2 shows a section through a locking arrangement according to the invention in locking position, and
Fig. 3 shows a section corresponding to Fig. 2, but with the locking arrangement in release position.
Description of illustrative embodiments
A seat 1 in a motor vehicle, which seat is shown in Fig. 1, is provided conventionally with a first safety belt 2 of the three-point type, which can be locked by means of a first locking device 3 disposed on one side of the seat and anchored in the vehicle. For increased safety, the seat 1 also possesses a second safety belt 4 of the two-point type, which is designed to extend diagonally across the seat and is locked by means of a second locking device 5, situated on the opposite side of the seat from the first locking device 3. The two locking devices 3 and 5 are linked by means of a connecting apparatus 6 and form together with this a locking arrangement 7 according to the invention.
The more detailed configuration of a locking arrangement 7 according to the invention can be derived from Figs. 2 and 3, in which the locking arrangement is shown, on the one hand, in locked position according to Fig. 2 and, on the other hand, in release position according to Fig. 3. The two locking devices 3 and 5 each constitute a somewhat modified variant of the well-known type of locking device which is described in, for example, American patent specification no. 4 353 151 and which, in this context, is only therefore described to the extent required for an understanding of the invention. For further details of the basic design, reference is made to the quoted patent specification. Other, similar locking devices could also probably suitably be used for a locking arrangement according to the invention, without thereby deviating from the basic solution set out below.
For simplification purposes, Figs. 2 and 3 do not show the protective sleeve, usually of plastic, which is intended to form part of each locking device 3 and 5 in order to enclose the mechanism shown. For attachment within the vehicle, each locking device 3, 5, is provided at the bottom with a fixture 8, to which a housing 9 is fixed in which a catch 10 is pivotably mounted about an axle 11 and is intended to engage with a locking section 12 in a locking opening 13 in a locking tongue 14 mounted on the associated safety belt, once the said locking tongue is introduced in the housing 9. Mounted displaceably in the housing 9
there is also an ejector 15, which in the drawing is spring-loaded in the upward direction and which endeavours to eject the locking tongue 14 from the housing 9. For operation of the catch 10, there is a control part 16 which is displaceable along the housing 9 and which is spring-loaded in the upward direction. The catch 10 can be held either in a locking position shown in Fig. 2 or in a release position shown in Fig. 3 by means of a spring-actuated catch apparatus 17 disposed in the housing 9.
The connecting apparatus 6 is here constituted by a wire device, in which a wire 18 is axially displaceable within a sleeve 19, the ends of which are fixed relative to the housing 9 in a respective locking device 3, 5. In the first locking device 3 the wire 18 is attached to the ejector 15, and in the second locking device 5 the wire 18 is attached to the control part 16, whereby a displacement of the ejector 15 in the upward or downward direction in the drawing within the first locking device 3 forces the control part 16 in the second locking device 5 to perform a motion in the opposite direction.
In the position shown in Fig. 2, a locking tongue 14 has been introduced into the housing 9 for the first locking device 3 to the point where the catch 10 could be pivoted to the locking position, at the same time as the ejector 15 has been forced downwards, counter to the spring force, and has thereby displaced the wire 18. This has allowed the control part 16 in the second locking device 5 to be brought up to a position which allows a locking tongue 14 to be introduced into and locked in the housing 9 in the same way as with the first locking device 3.
In the position shown in Fig. 3, unlocking has taken place as a result of the control part 16 in the first locking device 3 having been pressed down and having thereby allowed the catch 10 to be pivoted into the release position. Consequently, the ejector 15 has been forced upwards by spring force and has ejected the locking tongue 14 from the housing 9. At the same time, the control part 16 in the second locking device 5, via the wire 18, has been pulled down to and detained in a position in which the catch 10 can be pivoted into the release position, with accompanying upwardly directed motion of the ejector 15 and ejection of the locking tongue 14. Solely the control part 16 in the first locking
device 3 has therefore needed to be operated in order to release both the safety belts 2 and 4 simultaneously.
According to the invention, it is not possible to lock the second safety belt 4 in advance of the first safety belt 2. The reason for this is evident from Fig. 3. If an attempt is made first to lock the second safety belt 4 by introducing its locking tongue 14 into the second locking device 5, this will fail by virtue of the control part 16 being held in the release position and preventing the catch 10 from being pivoted into the locking position according to Fig. 2. If, on the other hand, the safety belt 2 is first applied by introducing its locking tongue 14 into the first locking device 3, the control part 16 in the second locking device 5 will be let up to a position in which the locking tongue 14 on the second safety belt 4 can be locked.
In the shown linkage of the locking devices 3 and 5 by means of the connecting apparatus 6, it is necessary for the spring force which actuates the ejector 15 in the first locking device 3 in the upward direction to be sufficiently large to produce the intended motion of the ejector 15 and also sufficiently large to simultaneously produce the intended downward motion of the control part 16 in the second locking device 5. This can be achieved by, in the first locking device 3, using a spring 20 to act upon the ejector 15 which is more powerful than in a conventional realization of the locking device 3. It is also possible to additionally install, according to Fig. 3, an extra compression spring 21 on the end of the connecting apparatus 6, thereby realizing the necessary force upon the ejector 15 in the first locking device 3. A combination of both these measures might possibly be used. Conversely, it is also possible, instead of fitting an extra compression spring 21 to the end of the connecting apparatus 6 in the first locking device 3, alternatively to fit an extra tension spring, acting upon the control apparatus 16, to the corresponding end of the connecting apparatus 6 in the second locking device 5.
The positioning of the attachment points for the connecting apparatus 6 on the two locking devices 3 and 5 can be chosen, within the scope of the invention, in many other ways than have been illustrated here. It is also possible to use another type of connecting apparatus 6 than that shown, for example some form of link mechanism. As previously pointed out, the two locking devices 3 and 5
can also, within the scope of the invention, have a partially different realization from that which has been described above.