In the absence of centrifugal force produced during rotation of helicopter blades, damage may result if a blade is rotated upward by wind or other forces. Lock units removably appended between the rotor assembly and each blade pitch housing attached to a helicopter blade are usable to restrict upward rotation. A base portion of a lock unit may be configured to be held in position by a removable pin device. An extendible device extending from the base portion to a surface of a blade pitch housing can be adjusted to press the base portion back against a surface of the rotor assembly. The lock unit thereby restricts these surfaces of the blade pitch housing and rotor assembly from moving closer to each other and thereby restricts upward rotation of the blade pitch housing and its attached helicopter blade. The lock units are readily removable in preparation for returning a helicopter to active use.

The invention relates to helicopter storage and shipment and, more particularly, to prevention of undesired upward rotation of helicopter blade pitch housings and attached blades during out-of-use periods.
Helicopter blades, during operation, are rotated basically in a plane of rotation which is nominally a horizontal plane. A helicopter blade is typically attached to a blade pitch housing (enabling controlled adjustment of blade pitch) which is attached to the rotor assembly, rotation of which produces blade rotation. While rotating, displacement or rotation of the blades upward from the plane of rotation is limited by the effects of centrifugal force. When out-of-use (e.g., parked, stored, in shipment) no centrifugal forces act on the blades and the blades and pitch housings are permitted to flap downward (called "droop") a small amount under the influence of gravity. Their weight is supported by a droop stop mechanism. When out-of-use the blades are typically unrestrained from a range of upward rotation (e.g., rotation in a vertical plane, about the connection point to the rotor assembly). Such upward rotation may be caused by wind forces while parked or stored, or by sudden altitude or attitude changes or other forces experienced during shipment of a helicopter in a transport aircraft or while being towed on the ground, for example.
During shipment or storage the blades of a helicopter may be folded (i.e., some or all blades positioned toward the tail or nose of the helicopter) while each blade still remains attached to its respective blade pitch housing which remains attached to the rotor assembly (blade folding is further described in U.S. Pat. No. 6,783,327, having a common assignee). Whether or not the blades are folded, upward rotation of a blade pitch housing, during shipment for example, is undesirable and may result in damage to the blade, the blade pitch housing or other components of the rotor blade mechanism, or to the interior area of a transport aircraft immediately above the stowed helicopter. For present purposes, uncontrolled upward rotation of a blade pitch housing (i.e., with its attached blade) of a helicopter which is not in use will be termed "flap". Correspondingly, undesired upward rotation of a blade may be termed "blade flap". Prior mechanisms and techniques have not provided effective limitation of blade flap or have been subject to limitations regarding cost, complexity, reliability, durability or other disadvantages.
Objects of the present invention are to provide new and improved lock units and methods, which may provide advantages such as the following:
ease of installation;
reliable operation;
absence of required aircraft modification;
cost effectiveness;
low complexity of construction;
durability; and
ease of removal.

Blade flap locking for out-of-use helicopters


A cannula for use in cataract surgery during the phases of hydrodissection and hydrodelamination/hydrodelineation/hydrodemarcation is described. The cannula has a hub for mating with a syringe and a needle originating from the distal end of the hub. The needle comprises a first section, second section, and truncated surface. The first section originates from the distal end of the hub and extends forward in a plane delineating the central longitudinal axis of the cannula. The second section originates from the distal end of the first section and is flattened and curved away from the central longitudinal axis of the hub. The truncated surface of the needle forms a rounded tip with beveled surfaces. The intersection of the bevel and sides of the cannula are sharpened to provide a cutting edge.

Embryologically, the human lens forms with a fetal nucleus which, after development, becomes the center of the crystalline lens. The inner side of the anterior capsule of the lens contain epithelial cells which migrate peripherally and posteriorly to lay down concentric lamellae of nuclear tissue. An adult nucleus next forms around the fetal nucleus and concentrically disposed lamellae, and the lens takes shape.
Throughout life, the epithelial cells continue to migrate and lay down lamellae of nuclear tissue. However, because the lens is now enclosed by the adult nucleus, the area of lens growth is confined causing the layers to become compressed and tightly packed. This increased compression and packing causes the lens to become stiff and firm, and by the age of 40 the ability of the lens to flex and focus is greatly reduced. As successive layers continue to be deposited, the lens becomes so dense that it begins to change color and the clarity is lost. At this point, the successively deposited layers of lamellae are referred to as a cataract. The inner nucleus of the cataract consists of a firm, dense material while the outer nucleus consists of a less dense material. The material surrounding the nucleus of a cataractous lens is known as the cortex.
Different terms are used to describe the surgical steps of separating the nucleus into its various components. Hydrodissection usually refers to an irrigation of fluid between the anterior capsule and the outer nucleus, essentially separating the outer nucleus from the cortex and even separating some cortex from itself.
The terms hydrodelineation, hydrodelamination, and hydrodemarcation are all synonymous and refer to the injection of fluid within the body of the cataract to separate the inner nucleus from the outer nucleus. In some instances, it is possible to cause multiple separations of the inner nucleus into several nuclei. This multiple separation is referred to as multilamellar delineation.
The instruments typically used to perform this function are blunt tipped cannulas generally between 25 and 30 gauge in diameter. The cannulas are attached to a syringe containing a balanced salt solution. During surgery, the rounded tip of the cannula is thrust into the wall of the capsular bag and into the lens therein to obtain a cleavage plane. A salt solution is injected into the cataract and the nucleus of the lens is hydrodelineated and decompacted.
Multilamellar delineation during the surgical phase of hydrodelineation may be accomplished using hydrosonics based on technology licensed to Alcon Corporation by Azis Aniz, M.D. A small needle is attached to an ultrasonic handpiece and high frequency ultrasound activates the tip, permitting deep penetration of the nucleus. A salt solution is injected into the nucleus and several cleavage planes (multilamellar delineation) are obtained due to the vibrating tip coming in contact with several lamellae. Unfortunately, this device costs just under $20,000.
A needle useful in ophthalmic surgery is disclosed by Thorton et al., U.S. Pat. No. 4,808,170. The needle is designed to administer posterior peribulbar or retro-bulbar anesthesia and contains a beveled tip on the distal end of the needle. The object of the needle is to penetrate by separating tissue instead of cutting tissue, therefore the tip and sides of the tip are rounded to provide a smooth transition between the bevel tip and side surfaces of the needle.
Straus, U.S. Pat. No. 4,759,746, discloses a retro-bulbar needle. The needle is for use in administering retro-bulbar or peribulbar anesthetics. The curved needle extends outwardly away from the longitudinal axis of the hub and then extends inwardly towards the longitudinal axis concluding with a terminal section which is straight and oriented at a predetermined angle to the longitudinal axis. The tip of the needle is rounded and beveled and the bevel is towards the concave aspect of the curved needle. The needle is curved so as to reduce the risk of retro-bulbar hemorrhage by violating less orbital space.
There are several structures of needles disclosed in other arts similar in construction to the apparatus disclosed herein such that they warrant discussion although they do not anticipate or make obvious the present invention. One such needle is disclosed by Yanus, U.S. Pat. No. 2,601,580. A portion of the needle shank is flattened by rollers to reduce the pain incurred by a patient when an otherwise rounded needle of equivalent cross sectional area is used. Also, the needle is beveled at the distal end and the beveled sides are sharpened to function as cutting edges.
Ginsburg, U.S. Pat. No. 2,899,959, discloses a hypodermic needle. The needle comprises a shank wherein the upper and lower shank sections are substantially parallel to each other and the axis of the intermediate part of the shank forms an obtuse angle with the axis of the upper section and an obtuse angle with the lower section. Also, the tip of the lower shank portion is beveled. The structure disclosed by Ginsburg helps to reduce problems normally associated with straight shanks such as the insertion point frequently scratching the vein walls causing pain, excessive limb movement causing the needle to slip out, and potential that a straight shank will not properly position itself for injection or withdrawal of blood.
Froning, U.S. Pat. No. 4,013,080, discloses a cannula connector useful in lumbar disc puncture. When the cannula is in proximity to the disc to be treated, a disc penetrating needle is inserted into the lumen o the cannula. The needle has a male luer-lock fitting for attachment to a syringe at its proximal end and a beveled tip at the distal end. The terminal section of the needle is also curved. The terminal section of the needle is curved to facilitate the maneuverability of the needle around obstacles.
While the prior art needles disclose structures with rounded beveled tip, curved shanks and flattened portions (in certain combinations), these needles are not suitable for obtaining multilamellar delineation during the cataract surgery phase of hydrodelineation/hydrodelamination/hydrodemarcation. One such method of achieving multilamellar delineation is through the hydrosonics device licensed to Alcon Corporation by Azis Aniz, M.D., however, this device is expensive as was noted previously.
Thus, there is a need for an inexpensive cannula for use in cataract surgery during the surgical phases of hydrodissection and hydrodelamination/hydrodelineation/hydrodemarcation.
Therefore, it is a primary object of this invention to provide an economically disposable cannula for use in cataract surgery during the surgical phases of hydrodissection and hydrodelamination/hydrodelineation/hydrodemarcation.
Another object of this invention is to provide an inexpensive cannula for use in cataract surgery that will isolate several cleavage planes (multilamellar delineation) during the surgical phase of hydrodelamination/hydrodelineation/hydrodemarcation.
A further object of this invention is to provide a curved cannula for use in cataract surgery that will permit better control of the instrument during the surgical phase of hydrodissection.
Another object of this invention is to provide a cannula for use in cataract surgery with a flattened shank section to rotate the nucleus during the surgical phases of hydrodelamination/hydrodelineation/hydrodemarcation and obtain improved cleavage of the nucleus when compared to circular cross-sectional cannulas.
Another object of this invention is to provide a cannula with a short length of needle to enable the cannula hub to be close to the eye thereby reducing unwanted leverage.
Still another object of this invention is to provide a cannula with a rounded tip and sharpened sides to engage, penetrate and irrigate additional tissue.


A method for feeding a yarn to a textile machine for its processing and preparation for subsequent use, such as an interlacing, texturizing-interlacing or doubling machine, the yarn including at least two threads (3, 4) which are bound together, the first thread (4) and second thread (3) unwinding from a corresponding bobbin, the first (4) of said threads (3, 4) being an elastomeric thread. This latter is unwound from the relative bobbin (6) by withdrawal under free tension, said elastomeric thread (4) then being subjected to tension regulation in order to feed it at constant tension to the next stage, in which it is bound to the other thread.

1. Field of the Invention
The present invention relates to a method for feeding a yarn to a textile machine for its processing and its arrangement for subsequent use. The invention also relates to a textile machine of the aforestated type in which said method is implemented.
2. Description of the Related Art
A textile machine of the aforesaid type, such as a texturizing-interlacing, interlacing or doubling machine, is known to operate on a yarn comprising at least two threads which are secured together (for example interlaced) in order to be collected on a support (a bobbin or spool) for subsequent use in producing an article in a corresponding different textile machine.
Such known textile machines for transforming textile fibres or yarns combine several identical or different textile fibres or yarns in order to transform the group of fibres or yarns into a yarn or fibre having characteristics which are a combination of the characteristics of each fibre or yarn combined in this manner.
In such machines the production process is normally very lengthy, varying from 30 minutes to more than 60 minutes, depending on the counts processed and on the dimensions of the yarn spool or bobbin produced. The process is also normally highly automated, using autodoffing of the spool produced.
In many of these machines, and in particular in machines for interlacing or texturizing and interlacing a synthetic fibre or thread such as nylon or polyurethane with an elastomeric fibre or thread, this latter is fed to the machine processing region by the so-called Deruile' method, i.e. by unwinding and feeding the yarn from its rotating support bobbin at a speed synchronized with the rate at which the processed yarn is collected on said spool or bobbin. In other words, the bobbin supporting the elastomeric thread rotates about its axis at a speed synchronized with the rotational speed of the bobbin or spool on which the yarn is collected after its processing, said synchronized speed enabling the elastomeric thread to be fed to the machine production region at a constant tension determined on the basis of requirements.
Consequently the ratio of collection speed to elastomer feed speed determines the tension or extension of this latter.
This yarn feeding method presents many limitations related to the modality of continuing yarn feed when the elastomeric thread bobbin runs out. For example, in such machines it is not possible to use the known so-called "head-tail" technique, which when a yarn bobbin has run out enables the production process to continue without interruption because of the presence of a second bobbin, the head of which (i.e. the commencement of the thread supported by it) is linked or rather knotted to the tail of the first (i.e. to the end of the thread supported thereby); the reason for this impossibility is that the threads of these bobbins cannot be knotted together because one of them rotates.
Changing the thread bobbin automatically is extremely complex, costly and limited because when a first bobbin of elastomeric thread runs out it is evidently not possible to automatically start the second at full speed.
Moreover if the elastomeric thread breaks in proximity to its end on the relative bobbin, to prevent its further rapid breakage (with consequent further halting of the textile machine) it is preferred to discard the depleting bobbin for a new bobbin; this evidently results in high costs caused by production discards.
In any event, the known method of feeding the textile machine with the elastomeric thread while maintaining its tension constant by controlling the rotation of the corresponding bobbin never allows complete depletion of the bobbin, with consequent creation of rejects (with their associated costs). This is because the initial layers wound on the preparation bobbin causes it to break the thread on the next before its complete depletion.
For this reason, "Derule'" feed devices require the presence of sensors for monitoring yarn breakage and sensors for indicating the bobbin end. In addition, as a textile machine of the stated type comprises numerous parts ("heads"), each for automatically producing a processed yarn, the number of such "heads" assigned to an operator is very high resulting, in the case of yarn breakage, in prolonged intervention downtimes which can heavily affect final production efficiency levels.

Method and machine for feeding a yarn to a textile machine with automatic replacement of the yarn if interrupted or when its bobbin becomes empty