US1693503A - Tail skid for airplanes - Google Patents

Description

Nov. 27, E928,

c. w. DW ORACK TAIL SKID FOR AIRPLANES Filed March 18, 1924 11v VEN OR effzarlas WDwaraw/fi a r flaw? .4 TTO NEY Patented Nov. 27, 1928..

UNETED arns CHARLES W. .DWORACK, OF DAYTON, OHIO.

TAIL SKID FOR AIRPLANES.

Application filed March 18, 1924. Serial No. 700,101.

This invention relates to tail skids for airplanes, and is generally concerned with the provision of a practical form of skid atford ing a support for the tail which renders the operation of turning on the ground less difficult so that manual assistance is uimecessary and wherein the worn portion of the skid may be renewed with minimum labor.

Witlr the above-stated object in mind the present invention provides a tail skid bar pivoted in the fuselage, and having the usual shock absorbing means restraining its pivotal movement at the time of impact with the ground and having a pivoted skid shoe capable of a limited amount of swinging movement on the free end of the bar, the latter having renewable wear ribs welded thereon so that the matter of replacing the same involves merely the removal of the shoe instead of the entire skid assembly.

In the accompanying drawin illustrating the invention, 7

. Fig. 1 is a View of the tail portion of an airplane fuselage showing my improved tail skid. v v

' Fig. 2 is a bottom view of the skid shoe which is pivotally mounted on the end of the skid bar.

Referring to. the drawing, the skid bar 10 is shown pivoted at 11 on a bracket 12 in the tail end of the fuselage. The inner end of the bar 10 has a U fitting 13 bolted at 14 which embraces a tube 15 rigidly mounted in parallel relation to the bar 10 in the fuselage. A shock absorbing cord 16 is Wound about the bar 10 and tube 15 above a flange 17 provided on the bar 10 so that the pivotal movement of the bar 10 at the moment of impact and while taxiing is yieldingly restrained. The U fitting 13 limits the extent of movement of the bar 10 by coming into engagement with the tube 15..

The outer end of the bar 10 is provided with a clevis 1'8 offset from the bar 10 to provide 5 a vertical pivot for the skid shoe 19. A bolt .20 passing through the clevis 18 secures the shoe 19 in position, and is preferably provided with a castellated nut 21 so that a cotter pin 22 may be employed to insure against to the accidental loosening of the bolt. The bolt 20, it will be noted, is hollow and has a springpressed ball closure 23 in the upper end whichyields upon, pressure of an oil can spout to admit oil to the bore thereof. This lubrication insures thefreedom of movementof the intact.

skid shoe 19 so that the plane may turn relatively freely on the ground, and no manual assistance is needed. It is apparent that the vertical pivoting of the shoe 19 onthe clevis of the bar 10, and the horizontal pivoting of the bar 10 in the fuselage provides a universal pivot mountso that the shoe swings sidewise to enable turning, and the bar 10 pivots on a horizontal axis to compensate for unevenness of the ground where the plane is taxiing or to give at the moment of impact when landing. The shoe 19 has laterally extending lugs 24 to limit the swinging movement thereof. These lugs engage the sides of the clevis 18 at the limits of movement of the shoe.

The skid shoe 19 is of.metal, preferably forged, and for lightness is made hollow with a channel-shaped cross section. This also gives it the maximum strength to Withstand the shocks to which it is subjected in taxiing and in landing.- The underside of the shoe 19 has a longitudinal sledding rib 25 which maintains the proper tracking relation of the shoe in taxiing. A cross rib 26 is provided near the trailing edge of the shoe which serves the purpose of braking the movement of the plane in landing. Both ribs are suit-ably welded to the shoe, and when they become worn to a certain extent, it is contemplated to remove the shoe and trim off the unused portions of the ribs and replace the same with new ribs. This operation is relatively simple and inexpensive. It was formerly the practice toremove the tail skid as a unit from the plane, thereby necessitating upon replacement, new shock-absorbing cord. This in itself is expensive, and the labor expended further renders this method of operation impractical. In the present case, it is necessary only to remove the bolt 20 to remove the skid shoe 19 and the remainder of the tail skid assembly isleft I claim 1. In a tail skid for airplanes, a skid shoe having renewable ribs welded on the bottom surface thereof, one being Welded longitudinally and another cross-wise of the bottom surface. v

2. In a tail skid for airplanes, a skid shoe of metal to have renewable ribs welded on the bottom surface thereof, said shoe being formed hollow for lightness and being channel-shaped for strength.

In testimony whereof I aflix my signature.

CHARLES w. nwoaAoK.

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