The invention relates to a helmet holder for a vision device, in particular for a night vision device, according to the preamble of claim 1.
Various vision devices, for example night vision or thermal imaging devices, are used for very specific applications by military, police and border protection forces in order to be able to carry out operation under poor visual or light conditions or in darkness. Night vision devices, for example, amplify the low light level and produce an image visible to the human eye.
Night vision devices, like binoculars, can be used independently and manually. They are used—like binoculars—as a binocular version having separate eyepieces for each eye or as a monocular version having only one eyepiece.
In most cases, for example in military or police use, it is necessary for the user to have his hands free and for the vision device, for example a night vision device, to be fixed on the wearer's head, for example to be fastened to a head covering, preferably a helmet.
Depending on light conditions, the night vision device is used in an operating position in front of the user's eye or in a rest position in which the night vision device is held outside the field of vision of the user. For adaptation to the different head shapes and eye positions of the user, it is necessary to have adjustment mechanisms which enable the user to carry out adaptation to his personal needs.
In many applications, the user needs to obtain a constantly steady image, even in the case of extreme physical movements, such as running or jumping, or in the case of vibrations during driving; the eyepiece of the vision device should be capable of executing only a minimum relative movement. In other applications, the user is dependent on the night vision device being held in a position very close to the head, both in the operating position and in the rest position, and not projecting substantially beyond the user's head either in the horizontal direction or in particular in a vertical direction.
Simple helmet fixing means are known, for example from U.S. Pat. No. 4,457,461, which however have no possibility of enabling the night vision device to be removed from the field of vision under adequate light conditions without having to remove it by an inconvenient procedure.
For eliminating this deficiency, systems having pivot mechanisms are being constructed. An exemplary embodiment of this type is disclosed in DE-69321234. In the system described there, the night vision device is fixed by means of a connecting piece to a slide which is fixed by means of a pivot fitting to the fitting fixed to the head covering by a strut, in a manner so as to be rotatable about a pivot axis. The fixing of the operating and rest position is effected by a spring-loaded catch apparatus.
What proves to be disadvantageous in such arrangements is that the strut having an axel shaft forms an axis of rotation above the front helmet edge, with the result that, in the rest position, the night vision device projects very considerably beyond the body height of the user. Because of this circumstance, there is a considerable danger of damage when passing through door frames or other obstacles limiting the height of passage, and furthermore use in low rooms, such as in vehicle cabins, is greatly restricted.
In order to obtain a mounting which permits good movement about the pivot axis, a certain play is required between the components, and this is equally necessary for protection from jamming between the components of spring-loaded catch apparatuses. In summary, this results, in the locked positions, chiefly in the operating position of the vision device, to a greater extent owing to the long lever arm of the eyepiece relatively far away from the pivot axis, in an instability in the region of a few tenths of a millimeter. During fast running or in the event of vibrations, there is a relative movement between the user's eye and the eyepiece owing to inertia, which leads to an unstable image.
A further disadvantage is that the locking springs exert the spring force only in the immediate region of the operating and rest position and there is no compensation of the weight of the night vision device. In the event of sudden release of the locking in the rest position due to external effects, such as impact or during jumping, the night vision device may fall through its own weight with possibly great speed from the rest position into the operating position, which can lead to irritation and shock for the user and, if the helmet fits loosely, even to eye injuries.
In order to overcome the disadvantage of the prior art, an object of the present invention is to provide a holder for a vision device so that the vision device, in particular night vision device, is held in such a way that—during any use—a steady image which is as free of vibration as possible is obtained. Furthermore, or alternatively, a compact arrangement of the vision device should be possible both in the rest position and in the operating position. Furthermore, or alternatively, the vision device should remain held as reliably as possible in the rest position—even under impact-like effects—so that unintended, sudden swivelling of the vision device into the operating position, which may startle the user, is avoidable. Furthermore, or alternatively, in particular abrupt movements of the vision device, at least those from the rest position to the operating position should be damped.
This object is achieved by a holder for a vision device, in which the defining features of the independent claims are realized. Alternative or advantageous developments are described by the defining clauses of the dependent claims.
According to the invention, freedom from play of the holder—vision device system is ensured by the installation, the arrangement and the design of a spring-mechanism. The possible plays are pretensioned by spring force so that no plays become effective until this force has been overcome, since the interlocking of all parts due to the gaps between the individual components being closed under pressure of the spring force is completely retained.
If a damping element is co-ordinated with the rotating element which is arranged on the arm and is non-rotatably connected to the receptacle for the vision device, on movement of the vision device—at least on movement from the rest position to the operating position—its speed of movement is reduced at least over a partial range of the movement. Thus, shock or irritation or even possibly injuries to the user owing to uncontrolled hasty handling of the vision device or owing to unintentional swivelling of the device caused by external effects are avoidable. The movement takes place slowly and in a damped manner without the user being emotionally or physically impaired.
Such damping elements are provided according to the invention in particular in combination with the spring mechanism, substantially in a parallel position, but may also advantageously be used by themselves alone in known holders, specifically damping such abrupt movements of vision devices from a certain position—generally the rest position—to another position—generally the operating position.
The spring mechanism is furthermore dimensioned so that at least partial compensation of the weight of all moving parts occurs.
In order to limit the pivot movement and hence to fix the end operating position of the vision device in front of the user's eye, a stop element is provided, by adjustment of which the horizontal distance of the eyepiece of the vision device from the user's eye can be adjusted in a certain range.
The adjusting elements by means of which the position of the vision device relative to the position of the eye of a user wearing the helmet can be established are formed in such a way that the projection of parts of the vision device beyond the head height in the rest position is minimized. This is achieved by nesting of the elements effecting the vertical and horizontal adjustment.
Below, the invention is described in more detail purely by way of example with reference to an embodiment.
An arm 8 which a clamping screw for the lateral adjustment 14 fixes in the position desired by the user 1 is inserted in a laterally displaceable manner in a transverse groove 35 provided on the support element 7. The position of the arm 8 can be optionally fixed—as shown here—over the right eye or, alternatively in a second retained position 32, over the left eye. The use of two arms 8 having a pivot mechanism 43 and adjusting elements 10, 11 for the use of two night vision devices 2 is also possible. It will also be possible to provide a single arm arranged in the middle of the transverse groove for holding a binocular vision device.
The arm 8 supports a rotatably mounted receptacle 9 to which the night vision device 2 can be coupled. The first adjusting element 10 which is vertically adjustable in the operating position, permits the vertical positioning of the night vision device 2 relative to the position of the eye of the user 1 wearing the helmet 5 and furthermore a second adjusting element 11 for the horizontal positioning of the night vision device 2 relative to the position of the eye of the user 1 are displaceably inserted into the receptacle 9. Both adjusting elements 10, 11 are fixed in the position desired by the user by means of clamping screws 15 which project through slots 26 (cf.
The night vision device 2 is detachably fixed to the second adjusting element 11 by means of a push button 12.
The night vision device 2 shown here by way of example, substantially comprises a base body 39 comprising a low light level amplifier, an objective 4 and an eyepiece 3.
All plays in the region of the bearing 33a, 33b, 33c (
A transverse stiffening means 51 is arranged between the jaws of the first adjusting element 10, with the result that both a stiffening function and a protection function against possible penetration of dirt are provided when the first adjusting element 10 is moved downward. A bush 23 is provided for the electrical and mechanical connection to the vision device to be docked.
In a further embodiment, a damping element is used, shown here by way of example as hydraulic rotary damper 28. The force transmission takes place firstly from the arm 8 via a driver 29 to the outside of the damping element and secondly from the receptacle 9 via a cam 41 to the end face of the rotary damper 28. As a result of the dynamic torque resistance of the rotary damper 28, the speed of movement on changing the position of the night vision device 2 from the rest position to the operating position is reduced in order to avoid irritating and startling the user.
For protection from soiling, the arm 8 and the receptacle 9 are closed all round. In order to permit and/or simplify the mounting, openings are closed by one or more covers, for example a cover 21 for the arm 8 (cf.