GB2046551A

GB2046551A - Sight incorporating a range finder

Info

Publication number: GB2046551A
Application number: GB8009480A
Authority: GB
Original assignee: Bofors AB
Current assignee: Saab Bofors AB
Priority date: 1979-03-28
Filing date: 1980-03-20
Publication date: 1980-11-12
Also published as: NO800897L; SE430822B; NO149224B; DE3011316A1; NO149224C; DE3011316C2; GB2046551B; SE7902764L

Abstract

A weapon sight 1 includes a range finder, preferably a laser 8 range finder 12, 13, so arranged that when a sighted target arrives at a range preset on a knob 16 following depression of a button 15 by the operator, an indication, e.g. light from an LED 14, is projected into the operator's eye. <IMAGE>

Description

SPECIFICATION Sight incorporating a range finder This invention relates to a sighting device for a weapon, particularly for a light-weight weapon, comprising means for aiming the weapon at a target and a range finder for determining the range.

Aiming a weapon at a target generally requires a sighting device which includes means for determining the range of the target so that the superelevation can be determined. In the prior art this problem has been solved in various ways, either by means of instruments in which the range of the target is directly converted into a corresponding superelevation or instruments which are more simple and easy to operate but which require the gunner to adjust the superelevation in dependance on the measured range of the target. The former type of instruments are complicated and costly and therefore used preferably for larger weapons in which the weight and dimensions of the sight are not critical. The lastmentioned more simple instruments, however, are mainly used for light-weight and portable weapons in which a minimum of electrical energy is required and which have small dimensions.

A disadvantage of these simple instruments, however, is the increased time it takes to aim the weapon. Lightweight weapons are often provided with simple aiming means for use against low flying air targets. Such aiming means may comprise markings of concentric rings, the so-called ring sight, ellipses or other similar symbols which are imaged at infinity so that the light rays are projected into the gunner's eye and via a transparent mirror in the so-called reflex sight. The aiming means may also comprise a dual-image sight in which a slightly reduced image of the target is brought into coincidence or into a particular size relationship with a corresponding unreduced image. For all these devices, however, correct target parameters, such as distance, velocity, angle of elevation etc. must be estimated.The setting operations based on these estimates to aim and fire the weapon must be carried out in a few seconds which make considerable demands on the gunner.

The main object of the present invention is therefore to provide a sighting device having a range finder which reduces the gunner's time for setting the weapon.

In accordance with this invention we provide a sight for a weapon comprising means for aiming the weapon at a target and a range finder for determining the range of the target characterized in that the range finder (13, 18, 23) activates signalling means at one or more predetermined target ranges.

In order that the invention may be readily understood embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which Figure lisa schematic view of a reflex sight according to the invention, Figure 2 is a schematic view of a dual-image sight according to the invention and Figure 3 is a schematic view of a sighting device for a rifle.

As illustrated in Figure 1, a reflex sight embodying the invention comprises a transparent reflecting plate or dichroic mirror 1, an objective lens 2, an inclined mirror 3 and an aiming marker 5 illuminated by a light 4. Through the reflecting plate 1, located at an angle to the top of the sight housing 6, the gunner observes the target at the same time as the aiming marker is imaged at infinity in the gunners eye by reflexion at the reflecting plate 1.

The reflex sight further comprises a laser range finder located in the sight housing 6 and comprising a transmitting optical system 7, a laser rod or similar device 8, a flash light 9, receiving optical system 10, a receiving diaphragm 11, a detector 12 and electronic units 13. The laser unit by itself is conventional and will not be described in detail. A signal diode 14, for instance a light emitting diode, is located in the aiming marker or in front of it, the diode being connected to the electronic units 13 so as to be activated when a target is located at a predetermined distance from the sight. The sight also includes a laser fire button 15 which activates the laser transmitter to emit a series of light pulses. By means of a hand wheel 16 for the distance it is possible to pre-set the tactical distance to a target, i.e. a distance which is appropriate for firing.In the figure only one such hand wheel for setting the distance is illustrated. It may be required, however, to use two wheels for setting two ranges. In certain cases the pre-selection wheel could be abolished and one or more tactical ranges be present by the electronic units 13.

The sight operates in the following way. The gunner observes the target area through the transparent reflecting plate 1. When a target appears the gunner presses the fire button 15 which activates the laser unit to cause the laser transmitter to emit pulses at a repetition rate of 1/20 second. The gunner keeps the sight on the target and when the target has reached a distance which is appropriate for firing (for instance 11 hm) an output signal is produced by the electronic units of the range finder to illuminate the signal diode 14 which is the firing signal to the gunner. The procedure can be repeated at other ranges (for instance 5,5 hm). The electronic units could also be used for calculating the superelevation corresponding to the distance which is measured by the range finder. To achieve this more diodes, a figure or other symbols could be illuminated.Of course the laser range finder could be used also for presenting the distance on a display.

Figure 2 illustrates another embodiment of the invention in the form of a so-called dual-image sight 17. In this case the laser range finder 18 provides an auxiliary assembly for the sight 17. The dual-image sight is provided with two apertures, one aperture 19 through which the gunner observes an unreduced image of the target and its background and one aperture 20 through which a reduced image of the target is observed.

The laser range finder 18 is designed in the same way as the instrument illustrated in Figure 1 and comprises a laser fire button 15 and a pre-selection wheel 16 for setting the target distance Preferably the laser is arranged on a support which is common to the sight. The signal diode 21 is located at the bottom of the aperture 19 of the sight and connected to the laser receiver.

Figure 3 illustrates a further embodiment of the invention in the form of an accessory 23 having a dichroic mirror 22 for a rifle sight 24. The laser unit itself is designed in the same way as already illustrated in Figures 1 and 2. In this case, however, two signal diodes 25 are illustrated. The diodes are imaged on the dichroic mirror 22 at infinity by means of a collimating lens 26. In conformity with the embodiments already described the laser unit is provided with a laser fire button 15 and a preselection hand wheel 16.

In the above-mentioned examples the optical signal for the gunner is provided by the laser range finder energising one, or two as in Figure 3, signal diodes, preferably light emitting diodes, as soon as a predetermined tactical distance to the target has been reached. The signal source may contain a number of illuminated and unilluminated light emitting diodes, figures or other symbols. Preferably the signal diodes are located in such a way that they are imaged in the sight at infinity.

The electrical signal applied by the laser range finderto the signal diodes can be made longer orshorter as desired. Preferably the signal may consist of a number of short pulses and a long main pulse, which makes it easier for the gunner to observe the firing signal.

Claims

1. A sight for a weapon comprising means for aiming the weapon at a target and a range finder for determining the range of the target characterized in thattherangefinder(13, 18,23)activatessignalling means at one or more predetermined target ranges.

2. A sight according to Claim 1, including means in said range finder to manually set predetermined target ranges.

3. A sight according to Claim 1, including means in said range finder to set predetermined target ranges.

4. A sight according to Claim 1, wherein the range finder includes a laser unit comprising a laser transmitter and a laser receiver.

5. A sight according to Claim 4, wherein the laser unit comprises means (15) for activating the laser transmitter to produce a number of repetitive light pulses.

6. A sight according to Claim 1, wherein said signalling means comprises one or more light emitting diodes (14,21,25).

7. A sight according to Claim 6, wherein said signalling means is imaged at infinity in the aiming means.

8. A sight according to any one of the preceding claims in which said signalling means produces a plurality of short pulses and a comparatively long pulse.

9. A sight according to Claim 1, including a dis play coupled to the range finder to optically present the measured range.

10. A sight substantially as described herein with reference to Figure 1 of the accompanying drawings.

11. A sight substantially as described herein with reference to Figure 2 of the accompanying drawings.

12. A sight substantially as described herein with reference to Figure 3 of the accompanying drawings.