GB2171783A - Firing and guiding apparatus - Google Patents

Abstract

A firing and guiding apparatus for rocket propelled projectiles launched from firing tubes has a support 1 which carries the firing tube 6 and the sight system 5 and which can be adjusted in both elevation and azimuth by an aiming grip 7. For this purpose the support 1 is mounted pivotably about a vertical shaft 11 on a base. The bearing for the elevation includes a harmonic drive gear 12 of which the elliptically shaped internal part 13 is driven by shaft 17 to which the aiming grip 7 is secured. <IMAGE>

Description

SPECIFICATION Firing and guiding apparatus for tubelaunched projectiles This invention relates to a firing and guiding apparatus for rocket propelled projectiles launched from firing tubes having a supporting system which is laterally and vertically adjustable by means of an aiming hand grip and which is pivotably mounted about a horizontal axis on a bearing assembly.

An apparatus of this kind is described in DE 12 66 665, wherein the gearing for the elevation is undamped and comprises a gear quadrant rotatable about a horizontal axis and engaging a worm gear rotatably mounted in a gear housing, the aiming grip being connected to the worm via bevel gears. For the traversing movement the bearing body has a bearing pin mounted pivotably about the vertical axis by means of two axial needle bearings and a radial needle bearing. The gearing for the traversing movement is damped by a damping device provided underneath the three needle bearings and comprising a number of parallel closely spaced discs affixed to the bearing pin and to the base in alternation with a damping fluid being provided between the discs. This known apparatus is comparatively bulky.

An object of this invention is to provide a more compact firing and guiding apparatus.

According to this invention there is provided firing and guiding apparatus for rocket propelled projectiles launched from firing tubes, the apparatus having a support which accommodates the firing tube and sight system, the support being vertically adjustable by an aiming handgrip which is pivotably mounted about a horizontal axis on a bearing assembly, the said assembly being pivotably mounted about a vertical axis on a base, and the assembly having a gear for elevation movement and a bearing for traverse movement, in which apparatus the gear for the elevational movement comprises a harmonic drive gearing of which the elliptically shaped internal part is driven by a shaft to which the aiming hand grip is secured.

Harmonic drive gears are already known (cf.

leaflet from Harmonic-Drive-System GmbH, 6070 Langen, Fed. Rep. of Germany) and comprise an elliptical internal part, the socalled wave generator, with an attached roller bearing, an externally toothed resilient cylindrical steel bushing, the so-called flexible spline which undergoes deformation by the wave generator and an internally toothed outer ring, the socalled circular spline, comprising a fixed steel ring of which the teeth continuously engage those of the elliptically deformed flexible spline via the larger diamater.

The tooth engagement range covers about 15% of the total number of teeth. The tooth distributions of the flexible spline and circular spline are the same. The number of teeth, however, differs by, for instance, two teeth, The pitch circle diameter of the flexible spline is thus smaller than that of the circular spline by an amount equivalent to two teeth. The rotation of the wave generator is thus accompanied by a relative movement, which if the wave generator is driven and the flexible spline is static, leads to a transmission ratio between wave generator and circular spline.

According to the invention the shaft to which the hand grip is secured drives the wave generator. The transmission ratio in the apparatus is preferably between 60 and 120.

The harmonic drive gearing of the apparatus according to the invention is preferably damped and it is then of advantage for the damping device to be integrated within the aiming hand grip.

The gear for the traversing movement is preferably constructed as a damped four-point bearing.

This makes it possible in the apparatus of the invention to provide independent damping devices for the elevation and for the traversing, the damping effect being adjustable. A further advantage is that the two damping devices can be adjusted independently of their respective bearings and gears, that is regardless of the bearing friction. Both damping devices may have an automatic temperature compensating system.

One embodiment of apparatus according to the invention is described in more detail with reference to the accompanying drawing showing an example in sectional view.

Referring to the drawing, a support 1 is provided which is mounted on a bearing body 3 by a bearing 4 so as to be pivotable about a horizontal axis 2. The sighting device of sighting system 5, indicated in broken lines, and the firing tube 6, also indicated in broken lines, are detachably secured to the support 1 by means of securing devices not shown in the drawing.

The bearing body 3 is fitted with an aiming grip comprising a handle 7 with which the support can be adjusted both in elevation and in the traverse directions. The bearing body 3 is also mounted rotatably about a vertical axis 11 of a four-point bearing assembly 10, on a bearing spigot 9 provided with The gearing for the elevation is formed by a harmonic drive gear 12 comprising an elliptically formed internal part 13 (wave generator) with an attached bearing 14 and an externally toothed elastic cylindrical steel bushing 15, (flexible spline) which undergoes deformation by the wave generator 13, and internally toothed outer ring 16 (circular spline).

The wave generator 13 is keyed onto a shaft 1 7 extending in the longitudinal direction into the handle 7. The shaft 17 is mounted on the bearing body by means of the bearings 18 and 19.

The flexible spline 15 is secured against rotation to that end of the bearing hody 3 which is remote from the handle 7. The circular spline 16 is mounted on the shaft 17 between the handle 7 and the wave generator 13, or at that end of the bearing body 3 which is remote from the handle 7 by the bearings 10 and 21.

A segment gear 22 is attached to that end of the circular spline 16 which is nearer to the handle 7 and interacts with a gear segment 22' affixed to the support 1.

The harmonic drive gear 12 is provided with a damping device 23 having a bush 25 rotationally secured to the bearing body 3, by a rapid-acting adjusting device 24.

The bushing 25 is positioned around the shaft 17 in an annular gap 26 formed by a concentric recess inside the handle 7. The annular gap 26 is filled with a damping fluid, such as silicon oil, and sealed by a packing 27 between the handle 7 and the bush 25 as well as a packing 28 between the bush 25 and the bearing body 3.

The shaft 17 also carries a sleeve 29, for example of teflon. The width of the annular gap 26 and the magnitude of the damping can be accurately adjusted by this means. As the bushing 25 is of metal, e.g. aluminium, and the sleeve 29 of plastic, such as teflon, a change in temperature results in a change in the gap and thus in automatic temperature compensation of the damping force.

The rapid adjusting device 24 enables the connection between the bush 25 and the bearing body 3 to be disengaged and the damping thus to be rendered inoperative, for example if in the case of airborne attack the support 1 has to be rapidly pivoted upwards.

The rapid adjusting device 24 comprises a bolt 31 which is biased by a spring 30 towards recesses provided on the periphery of the bush 25 and which is displaceable in the bearing body 3 and which is provided with an operating knob 32 situated adjacent the handle 7.

The mounting system for traverse consists of the bearing assembly 3 mounted on the bearing spigot 9 by the four-point bearing 10 and a damping device 33.

The damping device 33 has an annular space 34 positioned concentrically around the four-point bearing 10 and having a rectangular cross section containing an annular body 35 also of rectangular cross section, arranged so that a gap is formed between the wall of the annular space 34 in the bearing body 3 and the annular body 35. As the annular body 35 comprises a plastic such as teflon, and the wall on the other side of the gap of the bearing body 3 is metal, such as aluminium, a temperature change is accompanied by an alteration in the gap and thus automatic compensation of the damping force. This gap is filled with a damping fluid.

The annular body 35 is connected, in a rotationally secured manner, by means of a disc 36 to the bearing spigot 9. A recess in the said spigot 9 houses a rotational rate measuring device connected on the one hand with the body 3 and on the other with bearing spigot 9.

The rapid adjusting device can be dispensed with. It has also been found that the damping device 23 for the harmonic drive gearing or the elevation movement can likewise be omitted without any serious disadvantage. On the other hand, the damping device 33 for the traversing movement is normally indispensable for the satisfactory operation of the apparatus.

Claims (13)

1. Firing and guiding apparatus for rocket propelled projectiles launched from firing tubes, the apparatus having a support which accommodates the firing tube and sight system, the support being vertically adjustable by an aiming handgrip which is pivotably mounted about a horizontal axis on a bearing assembly, the said assembly being pivotably mounted about a vertical axis on a base, and the assembly having a gear for elevation movement and a bearing for traverse movement, in which apparatus the gear for the elevational movement comprises a harmonic drive gearing of which the elliptically shaped internal part is driven by a shaft to which the aiming hand grip is secured.

2. Apparatus in accordance with Claim 1, wherein a damping device is provided operatively associated with the harmonic drive gearing.

3. Apparatus in accordance with Claim 2, wherein the damping device is formed by a bush secured against rotation to the bearing body and an annular gap filled with a damping fluid and positioned between the shaft and the aiming hand grip.

4. Apparatus in accordance with Claim 2 or 3, wherein a sleeve is provided around the shaft.

5. Apparatus in accordance with any one of Claims 3 or 4, wherein the thermal expansion of the shaft and/or the sleeve and that of the bush and thus of the annular gap as well as the change in the viscosity of the damping fluid as a function of the temperature are adapted to one another to provide a damping force independent of temperature.

6. Apparatus in accordance with any one of Claims 3 to 5, wherein the bush is detachably secured to the bearing body.

7. Apparatus in accordance with any one of the preceding claims, wherein the externally toothed bush of the harmonic drive gear is rotationally secured to the bearing body, the internally toothed outer ring of the harmonic drive gearing being connected with the support through a reversing gear.

8. Apparatus in accordance with Claim 7, wherein the reversing gear comprises a pair of segment gears, one gear being secured to the internally toothed outer ring and the other gear wheel segment being secured to the support.

9. Apparatus in accordance with any one of the preceding claims, wherein for the traverse movement the bearing body is mounted by means of a four-point bearing and rotatable about a vertical axis on a bearing spigot affixed to the base.

10. Apparatus in accordance with Claim 2, wherein the damping device comprises an annular space within the bearing body and concentrically about the four-point bearing and an annular body secured to the bearing spigot and positioned in the annular space, the gap between the annular body and the bearing body being filled with a damping fluid.

11. Apparatus in accordance with Claim 10, wherein the thermal expansion of the annular body and the bearing body and thus of the gap between them together with the change occurring in the viscosity of the damping fluid as a function of temperature are adapted to one another to provide a damping force independent of the temperature.

12. Apparatus in accordance with any one of the preceding claims, wherein the externally toothed bush of the harmonic drive gear and the support are interconnected by a parallel crank chain in a backlashfree manner.

13. Firing and guiding apparatus constructed and arranged to function as described herein with reference to the drawing.