BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a safety belt for a vehicle having at least one belt strap which comprises a belt interior formed between two belt strap layers.

A safety system for occupants in a motor vehicle, having a motor vehicle seat and a safety belt associated with the motor vehicle seat is known from DE 10 2006 003 794 A1. A buckle tongue is fastened on the safety belt, for positively locking with a belt buckle which is secured to a motor vehicle structure. The extension length of the safety belt can be changed using a belt retractor, and the belt is connected to a gas generator which fills a tubular body with gas in the presence of appropriate sensor data and inflates the body, a gas supply line which can be extended together with the safety belt connecting the gas generator to the inflatable safety belt.

Furthermore, DE 10 2006 011 646 A1 shows a safety belt which comprises a heating element integrated in the belt strap.

The problem addressed by the invention is that of providing a safety belt which is improved over the prior art and has an integration of heating elements in the belt strap that is as advantageous as possible.

A safety belt for a vehicle has at least one belt strap which comprises a belt interior arranged between at least two belt strap layers. According to the invention, at least one heating element is arranged in the belt interior, adjacent to a belt strap layer facing the occupant wearing the belt strap.

By means of the heating element in the belt strap, a close-to-body heating, and thus climatization of the belt strap layer facing the occupant and thus of the occupant wearing the belt strap, can be achieved. Using comparatively little effort and a relatively low energy input, a relatively rapid heating of the occupant can be achieved in a region close to the body, such that it is not necessary to completely heat air in an interior of the vehicle. As a result, electrical heating energy can be saved.

If the vehicle is an electric vehicle or a hybrid vehicle having at least one electric drive unit, relatively high range losses, with respect to available electrical energy required for driving operation, are particularly noticeable in winter driving when outdoor temperatures are comparatively low, if air in the interior of the vehicle is heated by means of a heating device of the vehicle, such as an air conditioning system.

By means of the heating element, the comfort of the occupant can be significantly increased, particularly in the upper body area at the start of a journey when outdoor temperatures are comparatively low, it being possible to achieve a significant saving in electrical energy compared with a conventional heating of the interior.

Due to the fact that the belt strap can be heated, an influence of the cold at the start of the journey is at least significantly reduced by the belt strap on the upper body of the occupant who has put on the belt strap and in particular is not wearing a jacket.

Comfort is increased for the occupant at comparatively low outdoor temperatures, particularly in winter and even in a convertible, by means of the heatable belt strap, a wellbeing of the occupant or occupants, preferably a driver and a passenger of the vehicle, being increased at the same time.

Advantageously, the belt strap comprises an airbag which is arranged between two belt strap layers and can be supplied with gas, the heating element being arranged between the airbag and the belt strap layer which faces the occupant wearing the belt strap. In this case, a function of the airbag, which in particular triggers when an imminent collision of the vehicle is detected or when a collision of the vehicle is detected, is not impaired by the at least one heating element in the belt strap.

The belt strap advantageously has widened portions in the region of the belt interior, and is folded in this region, the relevant widened portion forming a support element for at least one heating element.

If the belt interior is supplied with gas by the airbag, the belt strap unfolds in this region, such that a contact surface of the belt strap on a body of an occupant is enlarged, and a force exerted by the belt strap on the occupant is distributed as a result. This can reduce a risk of injury to the occupant. In this case, a function of the belt interior, which can be supplied with gas and in particular triggers when an imminent collision of the vehicle is detected or when a collision of the vehicle is detected, is not impaired by the at least one heating element in the belt strap.

A heatable safety belt designed in this manner is technically comparatively easy to implement with relatively little effort, the benefit for an occupant wearing the seat belt being relatively high.

The safety belt can be standardized, such that a seat belt of this kind can be installed in all series, in particular of a vehicle manufacturer.

Embodiments of the invention are explained in more detail below with reference to drawings.

