The invention covered herein may be manufactured by or for the Government of the United States of America, for governmental purposes, without payment of any royalty thereon.
The invention relates to ski-rigging for aircraft. The object is to provide a ski-rigging which shall operate synchronously with the wheel-rigging.
The object is also to provide means whereby the ski, when moved from the down or operative position to the up or inoperative position, shall also be retracted during its upward movement, so that the forward end of the ski shall clear operative elements of the craft.
That is to say, when the ski is moved upwardly it is simultaneously moved rearwardly, and when moved downwardly into operative polstion the ski is also moved forwardly into original operative or running position.
These compound movements, of upwardly and rearwardly, and downwardly and forwardly, are secured by supplemental rigging elements attached to and operating with the wheel-rigging of well-known type.
The reason for this arrangement is that, in its operating or down position, its forward end should project about 65% of its length in advance of the axis of the wheel, and that In its upward movement to inoperative position its forward end should be retracted sufficiently to clear an operative part of the craft, such as the propeller.
Referring to the drawing, which illustrates merely by way of example, suitable means for. the embodiment of our invention; Fig. 1 is an elevation, showing part of the wheel-rigging, and showing diagrammatically elements of the ski-rigging connected to and operating with the wheel-rigging. In this arrangement the ski is shown in the down or operative position.
Pig. 2 is a similar view with the ski in the up or inoperative position.
Pig. 3 is a sectional detail of a resilient support for the rear end of the ski.
Similar numerals refer to similar parts through the several views.
In these figures it will be noted, that the bearing 10 is in supporting engagement with the axle of wheel II. This bearing and its axle If is connected to the lower telescoping end of element 12, which is also included in the shock-absorber.
This element 12 is pivotally secured at its upper end, as at 10, to the lower end of element 14; the upper end of which is secured to the fixed supporting pivot 15.
The telescoping element or strut 16 is secured at its lower end in pivotal relationship with the bearing 10, and at its upper end to the fixed supporting pivot 17.
These elements all form part of the conventional retracting type wheel landing gear.
The parts shown in heavy black lines, indicate the important parts of the ski-rigging which are connected to the wheel-rigging for synchronous actuation. The element I1 connects the bearing 10 of the wheel-rigging, to the forward part of the ski II as at 20. The left hand end of rod or strut 2 I is connected to the element 12, as at 22. At its other end, the rod or strut 21 is pivotallysecured,: as at 23, to the rod or strut 24, the lower end of which is secured to the rear part of the ski II as at 25. Another rod or strut 26, (which is jointed as at pivot 28) is connected at its upper end to the fixed supporting pivot I1 and at its lower end to the rod or strut 24, as at 27, which is intermediate the two ends of strut 24.
In Mg. 1, as above stated, the wheel II and ski 19 are shown in down or operative position. In such position the forward end of the ski projects about 60% of the ski length, forward of the axis of the wheel I . This is approximately the position of the ski for normal travel. In this position it will be noted that the forward end of the ski projects beyond the vertical line of the propeller 30 as shown in Fig. 3. In order therefore to permit the lifting of the ski without collision of the ski with the propeller, it is necessary to retract the ski rearward during its upward movement so as to clear the propeller; while in the downward movement it is necessary to provide a forward movement to normal running position when the Sski is lowered.
For example: In Fig. 1 the rigging is shown 40with the ski In down and running position. By moving the pivots 13 and 21 to the left to position shown in Fig. 2, the wheel and ski are shown elevated, and the ski retracted to clear the propeller 30 as indicated. By moving the pivots IS and 28 to the right the wheel and ski are carried downwardly to operative position, and at the same time the ski is moved to the forward position as shown in Fig. 1. These pivots 13 and 28 5o are adapted to be actuated by the usual hydraulic or mechanical control linkage of the wheel gear and retracting device.
Fig. 3 shows a resilient strut or similar device for controlling the rigging or trimming of the ski to conform to the level of the surface upon which the ski rests, and also to serve as a shock absorber.
The dot and dash line 31 extending from pivot 13 to 28 is merely to indicate that any suitable connecting means may be used for the simultaneous actuation of the said pivots.
What we claim is: 1. In a device of the class described, the combination with a ski for aircraft having landing wheels and rigging therefor, of a ski-rigging comprising linkage means adapted to connect said ski and said aircraft including means for positioning the major portions of said ski in advance of the landing wheel axes when the same are extended, for landing on said ski, and for retracting the major portions of said ski rearwardly of a vertical line passing through said wheel axes when the said ski is retracted.
2. In a device of the class described, the combination with a ski for aircraft having landing wheels and rigging therefor, of a ski-rigging comprising linkage means adapted to connect said ski and said aircraft including means for positioning the major portions of said ski in advance of the landing wheel axes when the same are extended, for landing on said ski, said positioning means being retractable to move the major portions of said ski rearwardly of a vertical line passing through said wheel axes when the said ski is retracted, said linkage means further including spring controlled strut elements, said element having means connecting the same to the rear end of the ski to thereby permit said ski, when in advanced position, to conform to the surface over which it travels.
3. The device defined in claim 2, and including means for communicating movement from the wheel rigging to the ski-rigging.
HENRY A. SIMPSON.
on AGNEW E. LARSEN.