EP0506696B1

EP0506696B1 - A crash helmet with an inflatable pad

Info

Publication number: EP0506696B1
Application number: EP91900219A
Authority: EP
Inventors: Claudio Zarotti
Original assignee: Vela SRL
Current assignee: Vela SRL
Priority date: 1989-12-19
Filing date: 1990-12-13
Publication date: 1994-06-29
Anticipated expiration: 2010-12-13
Also published as: IT1236889B; AU6899391A; IT8922735A1; WO1991008682A1; DE69010341D1; IT8922735A0; DE69010341T2; EP0506696A1

Abstract

The crash helmet (1) comprises a rigid head piece (2), a shockproofing pad (6) having at least one deformable, inflatable bladder (7), a diaphragm pump (16) driven by a battery-operated electric motor (17) and mounted to the head piece (2) to force air into the bladder (7), and a solenoid valve (18) between the pump (16), the bladder (7), and the outside environment to selectively and alternatively allow the bladder (7) to be shut off, air to be bled off the bladder (7) to the outside environment, or air to be pumped into the bladder (7).

Description

This invention relates to a crash helmet of a type which comprises an inflatable shockproofing pad.

Background Art

Known are crash helmets incorporating varying inflatable pads. As an example, US Patent 3761959 discloses a crash helmet provided with a pad which can be inflated through a special valve adapted to be coupled to an external inflating arrangement. After putting the helmet on in a fully deflated condition, the helmet is then inflated to a desired pressure to be "felt" directly by the user on inflating.
Such a crash helmet performs well in sporting events of relatively short duration; in this instance, the user would adjust the helmet before the start of a race, usually with the assistance of specially appointed personnel. In ordinary applications, however, such a crash helmet is instead unsatisfactory, both it practically disallows adjustment of the pressure while in use, and because the pressure adjustment procedure becomes quite complicated each time unless an assistant is available to operate the inflating arrangement.
Another inflatable pad crash helmet is disclosed by US Patent 4035846. With the latter helmet, the inside pressure is maintained at a preset value automatically by a valve, which would bleed air to the outside if the pressure is excessive and, when the pressure is too low, communicate to an external source of pressurized air to which the helmet is permanently connected. This prior helmet has been designed for use by airplane pilots, and meets the (basic in that case) requirement of holding the helmet firmly at a fixed position relatively to the head; different applications would be dependent on the availability of an external source of pressurized air to which the helmet should be kept connected while in use.
Another inflatable crash helmet is disclosed by DE-U-7729063; with this helmet it has been tried to render the helmet independent from external inflating means, by providing a built-in blower in the helmet. However, inflation by means of the blower results too slow and complicated, not compatible with a practical and safe use by a motorbike rider while riding.

Disclosure of invention

The underlying problem of this invention is to provide a crash helmet of a type comprising an inflatable pad, which can be readily and advantageously used without requiring connection to any external arrangement and which allows the user to easily and safely adjust pressure even while riding a motorbike or the like.
This problem is solved, according to the invention, by a crash helmet which comprises a rigid shell, a shockprooflng pad including at least one deformable, inflatable bladder, pumping means mounted to the shell for supplying air to the bladder interior through valve means, characterized in that the pumping means comprise a pump and an electric motor driving it, the helmet also comprising an electric storage battery for powering the motor, wherein the pump, the motor, the valve means and the battery are all housed within the helmet.
Further features and advantages of a crash helmet according to the invention will be more clearly understood from the following detailed description of a preferred embodiment thereof, to be read in conjunction with the accompanying drawings.

Brief Description of Drawings

Figure 1 is a side elevation view of a crash helmet according to the invention.
Figure 2 is a sectional view, drawn to an enlarged scale, of a detail of the helmet shown in Figure 1.
Figure 3 shows diagramatically a circuitry incorporated to the helmet shown in Figure 1.

Best Mode for Carrying Out the Invention

In the drawing figures, generally shown at 1 is a crash helmet, of the so-called wrap-around type, having a rigid shell 2 which is formed forwardly with an aperture 3 protected by a visor 4.
The helmet 1 includes a shockproofing pad 6 which has a deformable bladder 7 made preferably of polythene and traversing the interior of the shell 2, e.g. into a dendriform pattern having branches 8. Necked-in portions 9 are formed along the branches 8. Air is contained within the bladder 7 together with an air-pervious, sponge-like matrix 12.
The helmet 1 also comprises a pressure adjusting means 15, associated with the bladder 7 to vary the air pressure within the bladder.
This pressure adjusting means 15 comprises a miniaturized arrangement including a diaphragm pump 16 driven by a permanent magnet, DC electric motor 17. The motor 17 is to drive the pump 16 to force air into the bladder 7.
The pump 16 is connected to the bladder 7 via a solenoid type check valve 18, also of miniaturized construction. The solenoid valve 18 will, in the rest condition thereof, allow air to flow from the pump 16 into the bladder 7 but not vice versa. When energized, the solenoid valve 18 will communicate the bladder 7 with the outside environment through a bleed outlet 20. The miniaturized assembly comprising the pump 16 and motor 17 is of a type known per se, e.g. Model NMP 085 (6 Volts DC) by KNF NEUBERGER, a German manufacturer, and known is per se the solenoid valve 18.
The bladder 7 is advantageously provided with a relief valve 23 discharging to the helmet outside.
The crash helmet 1 further comprises a power supply means 19. This means comprises a line 29 led to a battery 22 housed in a special compartment 24 in the helmet 1. The battery 22 is adapted to power the various components of the helmet 1 via an electrical box 30 secured laterally on the helmet 1. The battery 22 generally comprises a set of batteries which may be of the re-chargeable type; provisions could also be made for connection to a solar battery to be mounted on the outer surface of the helmet 1.
The box 30 contains a storage unit 31 powered from the line 29. The storage unit 31 can be input a reference pressure value by means of a pushbutton M. Using additional pushbuttons, marked "+" and "-", gradual increases or decreases of the reference pressure value can be written in the memory. By means of a pushbutton T, a minimum pressure value can be stored whereat the bladder 7 would be set to such a condition as to allow the helmet to be taken off comfortably.
The air pressure inside the bladder 7 is sensed by a pressure transducer 33 arranged to face the bladder 7.
The box 30 also contains a comparator node 34 receiving, on a line 35 from the storage unit 31, the reference pressure value, and on a line 36 from the pressure transducer 33, the actual pressure value sensed, and issuing a difference signal. This signal is supplied to a control means 37 via a line 38. This control means is active between the line 29, on the one side, and the motor 17 and solenoid valve 18 on the other. On the comparator node 34 detecting substantial identity of the actual pressure with the pressure setting, the control means 37 will cut off both the motor 17 and the solenoid valve 18. By converse, on the comparator node 34 detecting a higher actual pressure than the set pressure, the control means 37 will turn on the solenoid valve 18 to bleed off air from the bladder 7 to the outside. Should the comparator node 34 detect instead a lower actual pressure than the set pressure, then the control means 37 turn on the motor 17 to cause the pump 16 to force air into the bladder 7.
The crash helmet 1 also comprises a microswitch 39 so arranged as to be operated by the user's head on putting on the helmet 1; the microswitch 39 will put the line 29 under power.
The crash helmet operation will be now described with reference to a starting condition whereby the helmet is to be worn and a generic pressure value is stored in the storage unit 31. The pad 6 inside the helmet 1 is at ambient pressure.
Directly on putting on the crash helmet 1, the microswitch 39 is operated by the user's head to enable the power supply 19. The electric current, under control by the control means 37 as driven by the difference between the pressure stored in the storage unit 31 and the actual inside pressure of the bladder 7 being sensed by the transducer 33, will energize the motor 17 of the pump 16 until the actual pressure within the bladder 7 equals the stored pressure level.
If the user wants a higher or lower pressure, he/she can operate the "+" or "-" keys to thereby vary the value of the stored pressure setting.
In use of the helmet 1, external factors such as changes in the ambient temperature may result in the bladder pressure being decreased or increased. This change would be promptly sensed by the transducer 33 and passed to the comparator node 34; as mentioned, the difference detected by the comparator node will activate the control means 37.
It should be noted that the response time, i.e. the time lapse from the occurrence of a pressure change within the bladder 7 and its correction, is on the order of a few seconds, in actual practice. Consequently, in the event of impact forces acting on the helmet and the bladder 7 undergoing a pressure increase as a result, such a pressure increase would not be corrected because it is a nearly instantaneous one with a duration time on the order of a few milliseconds, that is far shorter than the response time for correction. Accordingly, the pressure increase from the impact would be maintained in the helmet for a sufficient time to ensure that the desired shockproofing action is developed.
In the event that, due to failure, an uncontrolled excessive increase occurs in the bladder 7 pressure, the relief valve 23 bleeds air off.
When the user wishes to take the helmet off, he/she depresses the pushbutton T to cause a minimum pressure to be set in the storage unit 31 and, hence, quick deflation of the bladder 7. Thus, the helmet can be taken readily off the user's head.
A major advantage of a crash helmet according to the invention resides in its unique ability to fit around the user's head in a highly comfortable way. In fact, the helmet can fit around the head with optimum pressure of choice by the user.
A further advantage is that the comfortable fit can be maintained even with variations in the ambient and climatic conditions under which the helmet is used. In fact, the pressure level is monitored and adjusted continuously to keep it equal to the optimum value.
Another advantage of a crash helmet according to this invention is that it is fully self-sustained, it requiring no connections to any external arrangement.
In addition, a crash helmet according to the invention can be easily made to fit different size heads, thereby it can be put on sale as a single size, with attendant advantages of a practical nature.
Still another advantage of the inventive crash helmet is that it can be quickly taken off, either by the user in normal use, or by a possible rescue team with the user in an injured state.

Claims

A crash helmet (1) which comprises a rigid shell (2), a shockproofing pad (6) including at least one deformable, inflatable bladder (7), pumping means (16, 17) mounted to the shell (2) for supplying air to the bladder (7) interior through valve means (18), characterized in that the pumping means comprise a pump (16) and an electric motor (17) driving it, the helmet also comprising an electric storage battery (22) for powering the motor (17), wherein the pump (16), the motor (17), the valve means (18) and the battery (22) are all housed within the helmet (1).
A crash helmet according to claim 1, wherein the valve means (18) comprise an electric valve (18) powered by the storage battery (22) and connected to the bladder (7), the pump (16) and the outside environment, the electric valve (18) operating - in the rest condition thereof - as a one-way valve from the pump (16) to the bladder (7), and - in the working condition thereof - communicating the bladder (7) with the outside environment.
A crash helmet according to claim 2, further comprising a pressure sensor (33) located within the shell (2) for sensing the air pressure inside the bladder (7), a memory unit (31) wherein a desired pressure value is stored, a comparison circuitry (34) for comparing the pressure value stored in the memory unit (31) to the one sensed by the sensor (33), and a control circuitry (37) driven by the comparison circuitry (34) for controlling the power supply to the motor (17) of the pump (16) and to the electric valve (18).
A crash helmet according to claim 2, further comprising an electric switch (39) arranged within the shell (2) so as to be operated by the user's head on putting on the helmet (1).