Redundant pitch link

Claim 2

A dual, load carrying, structural link adapted to be connected to a member which comprises: an attachment means to connect the lend to a member; a primary member connected to said attachment means for carrying loads; a secondary member joined to said attachment means for carrying loads in the event said primary member is unable to carry loads, said secondary member being substantially unloaded while said primary member is carrying the load; and a layer of resilient material interposed between said attachment means and said secondary member so as to maintain the relative position of said secondary member with respect to said primary member when said secondary member is substantially unloaded.

Claim 3

The link of claim 1 wherein said resilient material is teflon fabric.

Claim 4

The link of claim 1 wherein said primary member is hollow and said secondary member is located therein.

Claim 5

The link of claim 3 wherein said primary and secondary members are turn buckles each of which includes a barrel and a pair of rods each of which is adapted to threadably engage one of the ends of said barrel.

Claim 6

The link of claim 4 wherein each primary rod has a hole therein, each secondary rod has a hole therein of a larger diameter than the diameter of the hole in said primary rod, said resilient material is adhered to the wall of the hole in said secondary rod, said secondary rod is aligned within said primary rod with the holes thereof having a common center to form a single opening, and said attachment means is inserted in said opening and secured therein.

Claim 7

The link of claim 1 wherein: said primary member includes a primary barrel, a pair of hollow primary rods each of which is threadably engaged with said primary barrel at one end while at the other end a hole is provided therethrough; said secondary member includes a secondary barrel located concentrically within said primary barrel, a pair of secondary rods each having one end threadably engaged with an end of said secondary barrel with the other end having a hole therethrough of a diameter greater than said hole in each of said primary rod, each secondary rod being located within one of said primary rods such that the holes passing through said primary and said secondary rods are aligned to form an opening at the end of said link; and said attachment means includes a pair of self aligning bearings each of which has an outer race and is located in said opening at either end of said link with the outer race being in firm contact with the abutting surface of said primary rod.

Claim 8

The link of claim 6 wherein said primary barrel is secured to said secondary barrel so as to prevent rotation therebetween.

Claim 9

The link of claim 7 wherein said pairs of primaRy rods and secondary rods are threaded so as to enable the length of said link to be changed upon rotation of said primary barrel.

Claim 10

The link of claim 6 wherein said pair of secondary rods have flattened ends which abut and overlay each other within said secondary barrel when said rods are threadably engaged therewith, thereby preventing rotation of one secondary rod with respect to the other secondary rod.

Claim 11

The link of claim 6 wherein said resilient material is teflon fabric.

Claim 12

A helicopter pitch link for use in linking a helicopter rotor blade to a control system comprising: a primary barrel; a pair of hollow primary rods, each being adapted to be threadably connected at one end of said primay barrel while having a bifurcated opposite end with a hole therethrough, a secondary barrel located concentrically within said primary barrel; a pair of secondary rods, threadably connected to opposite ends of said secondary barrel, the opposite ends of said secondary rods having a hole located therein of a diameter greater than that of the holes passing through the bifurcations of said primary rods, said secondary rods each being located within each of said primary rods such that the holes in said primary and secondary rods are aligned and form an opening at each end of said link; a pair of self aligning bearings having an outer race, each bearing being located in the opening at the ends of said link, each outer race being in firm contact with the abutting surface of the respective primary rod, one of said pair of self aligning bearings being operably connected to the helicopter rotor blades and the other self aligning bearing being connected to the control system; and a resilient material interposed between said secondary rods and the outer races of said self aligning bearings.

Claim 13

A helicopter pitch link for use in linking a helicopter rotor blade to a control system comprising: a primary barrel; a pair of hollow primary rods, each being adapted to be threadably connected at one end of said primay barrel while having a bifurcated opposite end with a hole therethrough, a secondary barrel located concentrically within said primary barrel; a pair of secondary rods, threadably connected to opposite ends of said secondary barrel, the opposite ends of said secondary rods having a hole located therein of a diameter greater than that of the holes passing through the bifurcations of said primary rods, said secondary rods each being located within each of said primary rods such that the holes in said primary and secondary rods are aligned and form an opening at each end of said link; a pair of self aligning bearings having an outer race, each bearing being located in the opening at the ends of said link, each outer race being in firm contact with the abutting surface of the respective primary rod, one of said pair of self aligning bearings being operably connected to the helicopter rotor blades and the other self aligning bearing being connected to the control system; and a resilient material interposed between said secondary rods and the outer races of said self aligning bearings.

Claim 14

The helicopter pitch link of claim 11 wherein said resilient material is teflon fabric and said teflon fabric firmly lines each secondary rod to prevent direct contact between said bearing outer race and said secondary rod.

Claim 15

The helicopter pitch link of claim 11 wherein said primary barrel is prevented from rotating with respect to said secondary barrel by a screw passing through said outer barrel and threadably engaging said secondary barrel.

Claim 16

The helicopter pitch link of claim 11 wherein each rod of said pair of secondary rods has material removed from that end which threadably engages the inner barrel and is of sufficient length so that said pair of secondary rods overlap and abut against one another when engaged with said secondary barrel thereby preventing said secondary rods from rotating with respect to one another.

Claim 17

The helicopter pitch link of claim 11 wherein each primary rod and the secondary rod located therein have threads in the same direction and pitch and which are machined so as to permit simultaneous engagement of said rods with their respective barrels.

Claim 18

The helicopter pitch link of claim 13 wherein one of the primary rods of said pair of primary rods and the secondary rod located therein are threaded in a common direction opposite to the direction of the threads of the remaining primary rod and the secondary rod thereby permitting the length of said link to be changed upon rotation of said primary barrel.

Claim 19

The helicopter pitch of claim 13 wherein one of the primary rods of said pair of primary rods and the secondary rod located therein are threaded in a common direction and have a pitch which is different but in the same direction from that of the threads of the remaining primary rod and secondary rod thereby permitting the length of said link to be changed upon rotation of said primary barrel.