Patent Description:
Pressure vessels are subject to damage during transportation and use due to, for example, collision with other objects or being dropped. The ability of a vessel to retain a fluid at a desired pressure may be compromised by such damage. An existing approach to damage mitigation is to adhere a protective cap to an end of the vessel. However, caps that are merely adhered to the vessel may become dislodged during vessel use. Other approaches include increasing the shell thickness, applying elastomer shell coatings, and adding protective layers or end caps that are fully covered or encapsulated by additional shell material. For further details, please see commonly owned <CIT> for a "Pressure Vessel with Damage Mitigating System" and commonly owned <CIT> for a "Wound-In End Protection Component for Pressure Vessel. " Because additional coatings or layers generally fully cover a damage-mitigating piece or the entire vessel, some approaches have the disadvantage of significantly increased material usage and manufacturing complexity.

<CIT> discloses a machine for winding pipes, in particular from resin-impregnated fiber material webs, onto domes which are moved in a rotatable carrier and mounted therein at constant angular intervals, with automatic dome feed and removal.

In one aspect, an assembly is configured for use in a system for forming filament windings on a vessel having a circumference and a length, as set out in claim <NUM>. Additional features of the invention are set out in the dependent claims.

In another aspect, a method of using a machine for forming filament windings on a vessel having a circumference and a length is described, as set out in claim <NUM>.

This summary is provided to introduce concepts in simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of the disclosed or claimed subject matter and is not intended to describe each disclosed embodiment or every implementation of the disclosed or claimed subject matter. Specifically, features disclosed herein with respect to one embodiment may be equally applicable to another. Further, this summary is not intended to be used as an aid in determining the scope of the claimed subject matter. Many other novel advantages, features, and relationships will become apparent as this description proceeds. The figures and the description that follow more particularly exemplify illustrative embodiments.

The disclosed subject matter will be further explained with reference to the attached figures, wherein like structure or system elements are referred to by like reference numerals throughout the several views. All descriptions are applicable to like and analogous structures throughout the several embodiments, unless otherwise specified.

While the above-identified figures set forth one or more embodiments of the disclosed subject matter, other embodiments are also contemplated, as noted in the disclosure. In all cases, this disclosure presents the disclosed subject matter by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that fall within the scope of the principles of this disclosure.

The figures may not be drawn to scale. In particular, some features may be enlarged relative to other features for clarity. Moreover, where terms such as above, below, over, under, top, bottom, side, right, left, vertical, horizontal, etc., are used, it is to be understood that they are used only for ease of understanding the description. It is contemplated that structures may be oriented otherwise.

The terminology used herein is for the purpose of describing embodiments, and the terminology is not intended to be limiting. Unless indicated otherwise, ordinal numbers (e.g., first, second, third, etc.) are used to distinguish or identify different elements or steps in a group of elements or steps and do not supply a serial or numerical limitation on the elements or steps of the embodiments thereof. For example, "first," "second," and "third" elements or steps need not necessarily appear in that order, and the embodiments thereof need not necessarily be limited to three elements or steps. Unless indicated otherwise, any labels such as "left," "right," "front," "back," "top," "bottom," "forward," "reverse," "clockwise," "counter clockwise," "up," "down," or other similar terms such as "upper," "lower," "aft," "fore," "vertical," "horizontal," "proximal," "distal," "intermediate" and the like are used for convenience and are not intended to imply, for example, any particular fixed location, orientation, or direction. The singular forms of "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

This disclosure recognizes that it is desirable to protect a pressure vessel against damage in a reliable and low-cost manner. It is of particular interest to protect the ends of the pressure vessel, as they may be most susceptible to damage due to their placement and generally hemispheroidal shape. In illustrative embodiments, a dome cap is formed by resin-impregnated composite filaments wrapped about the end portion of the vessel. The dome cap may be secured to the vessel at the time of vessel manufacture or may be retrofit to an existing pressure vessel at a later time. The disclosed concept uses less filament and resin than some prior protective systems in which an entire vessel is covered with layers of composite material. Moreover, formation of an end cap by cured wound filaments is more secure than adhesive bonding of a protective cap onto the end portion of the vessel.

<FIG> illustrates an elongated pressure vessel <NUM>, such as that disclosed in <CIT>, entitled "Pressure Vessel with Damage Mitigating System. " Such a pressure vessel <NUM> is typically used for storing pressurized fluids. Vessel <NUM> has a substantially cylindrical main body section <NUM> with dome ends <NUM>. When vessel <NUM> is fully formed, a boss is typically provided at one or both ends of the vessel <NUM> to provide a port for communicating with the interior of the vessel <NUM>. Vessel <NUM> can be formed with an interior fluid impermeable liner covered by an outer composite shell. A vessel end <NUM> typically has a hemispherical or domed shape.

Suitable pressure vessel shell materials include metals, such as steel; or composites, which may be formed of laminated layers of wound fiberglass filaments or other synthetic filaments bonded together by a thermo-setting or thermoplastic resin, for example. Composite construction of the vessels provides numerous advantages such as lightness in weight and resistance to corrosion, fatigue and catastrophic failure. These attributes are due at least in part to the high specific strengths of the reinforcing fibers or filaments that are typically oriented in the direction of the principal forces in the construction of composite pressure vessels. The composite shell resolves structural loads on the vessel.

A liner or bladder is often disposed within a composite pressure vessel shell to serve as a fluid permeation barrier, thereby sealing the vessel. Such a liner is often formed from a non-metallic (such as polymeric), resilient material and prevents internal fluids from contacting the composite material. Details relevant to the formation of an exemplary pressure vessel <NUM> are disclosed in <CIT>, entitled "Filament Winding Process and Apparatus.

As shown in <FIG>, an exemplary device <NUM> for stabilizing localized dome reinforcement for a pressure vessel includes rollers <NUM> and belt <NUM>. The device <NUM> is useful for gripping filament resin bands <NUM> as they are applied and pressing them to an outside surface of the dome end <NUM> of a pressure vessel <NUM>. In an exemplary method of using device <NUM>, wind eye <NUM> of winding machine <NUM> (shown in <FIG> and <FIG>) lays down layer upon layer of resin impregnated filament bands <NUM> to form a dome cap <NUM> for localized dome reinforcement, as shown in <FIG>. Filament windings may include a composite material fabricated of fibers or filaments contained in a resin, the fibers being of, for example, carbon, graphite, or aramid. In this case, "composite" means a fiber reinforced resin matrix material, such as for forming a filament wound laminated structure.

As shown in <FIG>, filament band <NUM> has been laid down on dome end <NUM> by wind eye <NUM>. As shown in <FIG>, the pressure vessel <NUM> rotates in direction <NUM> on a rotating shaft <NUM> (labeled in <FIG> and <FIG>, for example) attached to boss <NUM> as wind eye <NUM> travels left and right, as shown in <FIG>, <FIG>. On a left side of <FIG>, the top roller <NUM> applies pressure against a part of band <NUM> to prevent it from slipping toward the smaller diameter portion of dome end <NUM> near boss <NUM>. On a right side of <FIG>, belt <NUM> applies pressure against a part of band <NUM> to similarly prevent it from slipping toward the smaller diameter dome end. While the description refers to filament bands for ease of illustration and description, it is contemplated that any structure of filament windings may be used, including monofilament windings, for example.

As shown in <FIG>, in an exemplary embodiment, belt <NUM> is configured as an endless belt that wraps around the two rollers <NUM>. In an exemplary embodiment, the roller and belt assembly has two ends <NUM> with a clearance space <NUM> therebetween. In some configurations, compression belt <NUM> is provided as an endless belt held in tension around rollers <NUM> and <NUM> (shown in <FIG>). In an exemplary embodiment, compression belt <NUM> has a textured surface facing the pressure vessel <NUM> to grip and press onto a surface of the pressure vessel <NUM> and/or filament band <NUM> in contact with the compression belt <NUM>. Such a surface texture may be provided by integral formation of gripping elements on the belt or by the provision of additional structures such as surface spikes, for example.

As shown in <FIG>, <FIG>, the wind eye <NUM> travels with a reciprocating motion left and right through clearance space <NUM>. Simultaneously, the pressure vessel <NUM> rotates on rotating shaft <NUM> (labeled in <FIG> and <FIG>, for example) in direction <NUM>, resulting in an open, overlapping serpentine winding pattern of bands <NUM>, as shown in <FIG>. In an exemplary method, the winding continues so that bands <NUM> layer upon themselves to form a closed pattern dome cap <NUM>, as shown of <FIG>. While a particular rotation direction <NUM> is depicted in the illustrations, it is to be understood that an opposite rotation direction can also be used.

The reciprocal left and right motion of wind eye <NUM>, carried by carriage <NUM> (<FIG>), is repeated, cycling through positions as shown in <FIG>, to form a pattern of dome reinforcement bands as shown in <FIG>. Continued deposition of filament material in this manner eventually leads to the closed pattern of filament band <NUM> forming dome cap <NUM>, as shown in <FIG>. As shown in <FIG>, for example, the compression belts <NUM> grips filament band <NUM> simultaneously in several locations on pressure vessel <NUM>.

Dome cap <NUM> may be applied to a pressure vessel <NUM> in any stage of formation. For example, dome cap <NUM> can be applied to a polymeric liner of a pressure vessel before a remainder of a composite shell is applied to the liner. In other examples, dome cap <NUM> can be applied to a complete pressure vessel that already includes a composite shell. Moreover, the dome cap <NUM> can be applied to metallic pressure vessels and substantially cylindrical containers of many different materials and construction.

Providing for localized reinforcement of a pressure vessel at its curved dome ends <NUM> provides for savings in cost and manufacturing time over methods that cover the entire pressure vessel in additional layers of composite filaments. The disclosed device and method of reinforcing of pressure vessel <NUM> are suitably used in the formation of a dome cap <NUM> formed of filament bands <NUM> that include a resin with a relatively long pot life so that the resin may be cleaned from the compression belt <NUM>. A suitable resin is commercially available from Huntsman Corporation of The Woodlands, Texas as Araldite epoxy resin LY1135, for example.

As shown in <FIG>, in an exemplary embodiment, dome cap <NUM> completely covers dome end <NUM> of pressure vessel <NUM> and also extends onto a generally cylindrical portion <NUM> of pressure vessel <NUM> that is disposed between the two dome ends <NUM>. Because the filament bands <NUM> of the dome cap <NUM> are pressed onto the pressure vessel <NUM> -- by the assembly of rollers <NUM> and belt <NUM> -- and cured thereon with pressure, the dome cap <NUM> is securely bonded to the pressure vessel <NUM>. Moreover, additional filament wound composite resin strands can be disposed over dome cap <NUM> and pressure vessel <NUM> to form yet another composite shell over the vessel shown in <FIG>.

<FIG> is a perspective view of a winding machine <NUM> suitable for use with the described device <NUM>. Typically, winding machine <NUM> includes a frame <NUM> configured to support the pressure vessel <NUM> on rotating shaft <NUM>. Winding machine <NUM> further includes a controller <NUM> that is operably connected to a user interface <NUM> for receiving commands regarding reciprocal linear motion of carriage <NUM> which supports wind eye <NUM>, rotation of rotating shaft <NUM>, and the laydown speed and volume of resin impregnated filament material to form filament band <NUM> on a dome end <NUM> of pressure vessel <NUM>. Thus, different patterns and structural properties of filament bands <NUM> can be formed as designed and desired, upon command. As shown in <FIG>, <FIG> and <FIG>, winding machine <NUM> is modified with additional members of frame <NUM> to support the components of device <NUM>.

The disclosed stabilizing device <NUM> uses a belt <NUM> that moves with the rotation of the pressure vessel <NUM> to apply pressure to the vessel surface and allow local reciprocation of the path of wind eye <NUM> to deposit fiber, such as in the form of a filament band <NUM>, while preventing the fiber from slipping from the vessel surface. Such a stabilizing device can take many different forms, using different numbers of rollers, support devices and motion mechanisms than shown. <FIG> show exemplary embodiments of a stabilizing device <NUM> for use with winding machine <NUM>, further including arms <NUM> connected to respective position actuators <NUM> at pivot joints <NUM>. In an exemplary configuration as shown in <FIG>, an inside layer of the endless belt <NUM> contacts an outer surface of the pressure vessel <NUM> and wraps around rollers <NUM> proximate clearance space <NUM>. An outer layer of the endless belt <NUM> is held against support arms <NUM> by rollers <NUM>.

With this arrangement, a portion of the endless belt <NUM> extends around the diameter of the pressure vessel <NUM> while another greater length portion extends around rollers <NUM> and against and between support arms <NUM>. With this structure of the stabilizing device <NUM>, an effective length of the belt <NUM> around and in contact with pressure vessel <NUM> can be adjusted in various manners. Such adjustment can be used to accommodate a change in pressure vessel diameter as a thickness of the filament band <NUM> builds under the inner layer of the belt <NUM>. Additionally or alternatively, an effective length of the belt <NUM> around and in contact with pressure vessel <NUM> can be adjusted to accommodate different diameters of pressure vessels positioned in the winding machine <NUM> to receive dome reinforcement filaments thereon. <FIG> show four different manners in which device <NUM> can provide for effective belt length adjustability around different sizes of pressure vessels <NUM>. It is to be understood that the structures of all of these embodiments are described with reference to configurations in which the device <NUM> is extended over a pressure vessel <NUM>. While not specifically illustrated for each of these configurations, the devices are also retractable from the pressure vessel <NUM>, as shown in <FIG>.

A first adjustment arrangement is shown in <FIG>, wherein the configuration for a smaller diameter pressure vessel <NUM> is described with reference to <FIG>, and the configuration with respect to a larger diameter pressure vessel <NUM> is shown with respect to the structures shown in <FIG> is quite similar to <FIG>, and the descriptions of <FIG> apply accordingly. <FIG> shows the position actuators <NUM> in an extended position to shorten a length of belt <NUM> between rollers <NUM>. Therefore, an increased length of belt <NUM> can wrap around the larger pressure vessel <NUM>.

A second adjustment arrangement is shown in <FIG>, wherein the configuration for a smaller diameter pressure vessel <NUM> is described with reference to <FIG>, and the configuration with respect to a larger diameter pressure vessel <NUM> is shown with respect to the structures shown in <FIG> shows a configuration in which axle <NUM> of roller <NUM> is slidably received within slot <NUM> of channels <NUM>. As shown in <FIG>, to accommodate a larger diameter pressure vessel <NUM>, roller <NUM> slides to another point within channel <NUM> to increase the effective length of belt <NUM> wrapped around pressure vessel <NUM>. While not specifically shown, such roller motion can be supported by and controlled with an additional set of hydraulic and/or pneumatic cylinders.

A third adjustment arrangement is shown in <FIG>, wherein the configuration for a smaller diameter pressure vessel <NUM> is described with reference to <FIG>, and the configuration with respect to a larger diameter pressure vessel <NUM> is shown with respect to the structures shown in <FIG>. In <FIG>, support arm <NUM> is provided in a two-part configuration with mutually sliding and telescoping arm sections 54a and 54b. <FIG> shows the device <NUM> with a smaller pressure vessel <NUM>. Because relatively less length of belt <NUM> encircles the pressure vessel <NUM>, actuators <NUM> are extended to increase a distance between rollers <NUM> and <NUM>. A longer effective length of support arm <NUM> is accomplished by sliding arm portion 54b along arm portion 54a. In the illustrated embodiment, ends of each actuator <NUM> are attached, respectively, to support arm portions 54a and 54b. In <FIG>, actuators <NUM> are extended to accommodate the shorter arms <NUM>.

A fourth adjustment arrangement is shown in <FIG>, wherein the configuration for a smaller diameter pressure vessel <NUM> is described with reference to <FIG>, and the configuration with respect to a larger diameter pressure vessel <NUM> is shown with respect to the structures shown in <FIG> show an arrangement using an additional roller <NUM> on a portion of belt <NUM> spanning between the rollers <NUM>. As shown in <FIG>, an effective length of the belt <NUM> between the rollers <NUM> is increased by retraction of actuator <NUM>. As shown in <FIG>, actuator <NUM> is extended, to decrease the length of belt <NUM> between rollers <NUM> and increase an effective length of belt <NUM> around the larger pressure vessel <NUM>.

<FIG> show device <NUM> in a retracted configuration, wherein the rollers <NUM> are lifted off the pressure vessel <NUM>, as in directions <NUM> depicted in <FIG>. While not shown in some drawing figures to prevent obscuring of views of the described components, end <NUM> of each of the position actuators <NUM> is pivotally attached to frame <NUM> or another support of a modified winding machine <NUM>. In an exemplary embodiment, positioning actuator <NUM> is an extendable cylinder that can be actuated by means including the use of electronics or hydraulic or pneumatic fluid, for example. As shown in <FIG>, when the positioning actuators <NUM> are extended, the rollers <NUM> and belt <NUM> are retracted away from pressure vessel <NUM>. In an exemplary embodiment, this change in configuration is caused by pivoting of end <NUM> of position actuator <NUM> at its connection to frame <NUM> and pivoting of support arms <NUM> at an opposite pivot joint <NUM> of position actuator <NUM>. This retracted position of the stabilizing device <NUM> shown in <FIG> allows for insertion, removal, and other positional adjustments of pressure vessel <NUM> within the winding machine <NUM>.

A change in position between the extended device <NUM> shown in <FIG> and the retracted device <NUM> shown in <FIG> can be affected automatically by software run by controller <NUM> and/or controlled manually by user input into user interface <NUM>. While not specifically illustrated, any user interface may be used, such a one including a keyboard, monitor, touchscreen, knobs, buttons, or levers, for example.

As shown in <FIG>, in an exemplary embodiment of a device <NUM>, when rollers <NUM> are extended so that an inner layer of the endless belt <NUM> is in contact with a portion of an outer circumference of pressure vessel <NUM>, the arms <NUM> are inclined so that a distance between the pair of arms <NUM> at contact rollers <NUM> is less than a distance between the pair of arms <NUM> proximate rollers <NUM>, which are not in contact with pressure vessel <NUM>. Additionally, in an exemplary embodiment, as shown in <FIG>, a distance between the pair of arms <NUM> proximate contact rollers <NUM> is less than a distance between the pair of arms <NUM> proximate frame <NUM>.

In this manner, the clearance space <NUM> is maintained at a relatively small distance, sufficient to allow linear left and right motion of wind eye <NUM> via motion of carriage <NUM>. This configuration places an inner layer of the endless belt <NUM> in contact with a significant majority of the circumference of pressure vessel <NUM>. Thus, pressure is maintained by the rollers <NUM> and belt <NUM> on filament bands <NUM> laid on the pressure vessel surface in order to press the resin impregnated filament onto the pressure vessel surface and facilitate bonding between the filament band <NUM> and the underlying pressure vessel surface and underlying filament bands. By providing the compression belt <NUM> as an endless belt around rollers <NUM> (and in some embodiments also rollers <NUM>), the belt surface moves around the rollers <NUM>, <NUM> with the pressure vessel <NUM> as the pressure vessel <NUM> rotates on rotating shaft <NUM>. Thus, there is no relative motion at a contact point of belt <NUM> on the underlying pressure vessel surface or filament band <NUM>. Accordingly, uniform compression is applied to the pressure vessel <NUM> and the newly deposited filament bands <NUM>, without any slippage between the compression belt <NUM> and underlying surfaces of filament bands <NUM> or pressure vessel <NUM>.

Slippage between the belt <NUM> and the underlying liner or composite shell of the vessel <NUM> would displace composite material of the filament band <NUM> and could compromise the strength of the material. Thus, belt <NUM> is maintained under tension in order to keep a relatively high level of contact pressure with the underlying liner or composite shell of the vessel <NUM>. The high contact pressure also serves to prevent the ends of filament band <NUM> from pulling out from under the belt <NUM> as the winding band <NUM> pulls away in tension. An effective length of the belt <NUM> in contact with vessel <NUM> and its pressure application is selected by how the device <NUM> is positioned around vessel <NUM>. In one embodiment, all the rollers <NUM>, <NUM> are free wheeling (not driven); the rotating vessel <NUM> would supply the driving rotational force for the system. In an alternative embodiment, rollers <NUM> could be driven and turned at slightly different rates to create additional tension in the belt <NUM> in the region in contact with the underlying liner or composite shell of the vessel <NUM>.

The consistent application of pressure by belt <NUM> and rollers <NUM> provides for ease and reliability of manufacturing with few moving parts. The stabilizing device <NUM> remains in this consistent extended position as the wind eye <NUM> of the winding machine <NUM> traverses left and right, while the pressure vessel <NUM> simultaneously rotates on rotating shaft <NUM> in rotation direction <NUM>, to form the dome reinforcement pattern shown in <FIG>, which eventually results in the closed pattern of dome cap <NUM>, shown in <FIG>. As shown in <FIG>, the rollers <NUM> and belt <NUM> are movable into and out of position against pressure vessel <NUM>. After formation of the dome cap <NUM> is complete, the stabilizing apparatus <NUM> can be removed from the pressure vessel <NUM>, such as by retraction of rollers <NUM> and the attached belt <NUM> in directions <NUM>, as illustrated in <FIG>.

In an exemplary retracted configuration as shown in <FIG>, the support arms <NUM> are linearly aligned with each other in a substantially vertical configuration. This retraction moves the attached rollers <NUM> and belt <NUM> away from the surface of pressure vessel <NUM>. Thus, a position of the pressure vessel <NUM> relative to winding machine <NUM> can be adjusted, including removal of pressure vessel <NUM> from the winding machine <NUM>. In an exemplary method of reinforcing the dome ends <NUM> of a pressure vessel <NUM>, after the formation of one dome cap <NUM>, the pressure vessel <NUM> is turned so that its other dome end <NUM> is positioned for reception of filament bands <NUM> thereon, deposited by wind eye <NUM>. Thus, an exemplary completed pressure vessel <NUM> will have a dome cap <NUM> on each of the two opposed ends <NUM> of the pressure vessel <NUM>. In another method, both the wind eye carriage <NUM> and the device <NUM> are moved to the second end <NUM> of the pressure vessel <NUM> so that the vessel need not be repositioned within machine <NUM>. While <FIG> illustrate the adjustment arrangement of <FIG>, the adjustment arrangements of <FIG>, <FIG>, or <FIG> could be configured such that in a retracted configuration, the support arms <NUM> are linearly aligned with each other in a substantially vertical configuration.

<FIG> is a top plan view of an exemplary winding machine <NUM>, modified to support stabilizing device <NUM>, which is shown in the extended position illustrated in <FIG>. Wind eye <NUM> on carriage <NUM> traverses left and right (in directions <NUM>) to deposit filament band <NUM> in a low angle, helical winding pattern on pressure vessel <NUM>, as shown in <FIG>, for example. In one embodiment, the stabilizing device <NUM> can be attached to another carriage, such as at pivot end <NUM>, to also move in directions <NUM>. Thus, a position of the compression belt <NUM> along a length of pressure vessel <NUM> can be adjusted depending on a size of the pressure vessel <NUM> and configuration of its dome ends <NUM>.

Exemplary, non-limiting embodiments of an assembly and method are described. For example, an assembly is configured for use in a system for forming filament windings <NUM> on a vessel <NUM> having a circumference and a length, the assembly comprising an endless belt <NUM> and first and second rollers <NUM>. The endless belt <NUM> is configured to wrap partially around the circumference of the vessel <NUM> to contact and impart pressure on a filament winding <NUM> disposed on an outside surface of the vessel <NUM>. The endless belt <NUM> moves around the first and second rollers <NUM>. A space <NUM> is disposed between the first and second rollers <NUM> to allow passage of a filament wind eye <NUM> of the system configured to move in a reciprocal motion <NUM> along the length of the vessel <NUM>.

In an exemplary embodiment, the endless belt <NUM> moves around third and fourth rollers <NUM>. In an exemplary embodiment, the first roller <NUM> and third roller <NUM> are attached to a first arm <NUM> that is configured to connect to a frame <NUM> of the system. Moreover, the second roller <NUM> and fourth roller <NUM> are attached to a second arm <NUM> that is configured to connect to the frame <NUM>. In an exemplary embodiment, the first arm <NUM> comprises a channel <NUM> along which the third roller <NUM> is configured to roll.

In an exemplary embodiment, a first arm <NUM> is attached to the first roller <NUM> and configured to connect to a frame <NUM> of the system, and a second arm <NUM> is attached to the second roller <NUM> and configured to connect to the frame <NUM>. In an exemplary embodiment, a first extendable actuator <NUM> is disposed between the first arm <NUM> and the frame <NUM>, and a second extendable actuator <NUM> disposed between the second arm <NUM> and the frame <NUM>. In an exemplary embodiment, the first extendable actuator <NUM> is pivotally attached to the first arm <NUM>, and the second extendable actuator <NUM> is pivotally attached to the second arm <NUM>. In an exemplary embodiment, the first extendable actuator <NUM> is pivotally attached to the frame <NUM>, and the second extendable actuator <NUM> is pivotally attached to the frame <NUM>.

In an exemplary embodiment, the first and second arms <NUM> are movable between a first configuration shown in <FIG> and <FIG> and a second configuration shown in <FIG>. In the first configuration, the first and second rollers <NUM> place the endless belt <NUM> in contact with the outside surface of the vessel <NUM> and the filament winding <NUM> disposed thereon. In the second configuration, the first and second rollers <NUM> remove the endless belt <NUM> from contact with the outside surface of the vessel <NUM> and the filament winding <NUM> disposed thereon. In an exemplary embodiment, in the first configuration, a distance between the first and second arms <NUM> proximate the first and second rollers <NUM> is less than a distance between the first and second arms <NUM> proximate the frame <NUM>. In an exemplary embodiment, in the second configuration, the first and second arms <NUM> are aligned co-linearly.

In an exemplary embodiment, a method of using a machine <NUM> for forming filament windings on a vessel <NUM> having a circumference and a length is described. In an exemplary embodiment, the method comprises rotating the vessel <NUM> on a rotating shaft <NUM>; moving a filament wind eye <NUM> in a reciprocal motion <NUM> along the length of the vessel <NUM> while depositing a filament winding <NUM> on an outside surface of the vessel <NUM>; and wrapping an endless belt assembly <NUM>, <NUM> partially around the circumference of the vessel <NUM> to contact and impart pressure on the filament winding <NUM>. In an exemplary embodiment, a space <NUM> is disposed in the assembly <NUM>, <NUM> at the outside surface of the vessel <NUM> to allow passage of the filament wind eye <NUM>.

In an exemplary embodiment, the method comprises extending a belt <NUM> of the endless belt assembly around first and second rollers <NUM> about which the belt <NUM> moves. In an exemplary embodiment, wrapping the endless belt assembly partially around the circumference of the vessel <NUM> comprises extending a first arm <NUM> attached to the first roller <NUM> from a frame <NUM> of the machine <NUM> and extending a second arm <NUM> attached to the second roller <NUM> from the frame <NUM> of the machine <NUM>. In an exemplary embodiment, the method comprises retracting the first and second arms <NUM> to remove the belt <NUM> from contact with the outside surface of the vessel <NUM> and the filament winding <NUM> disposed thereon. In an exemplary embodiment, retracting the first arm <NUM> comprises extending a cylinder <NUM> that is pivotally connected to the first arm <NUM> and to the frame <NUM> of the machine <NUM>.

In an exemplary embodiment, the method comprises changing an effective length of the belt <NUM> between the first and second rollers <NUM> around the circumference of the vessel <NUM> in contact with the filament winding <NUM>. In an exemplary embodiment, the method comprises extending the belt <NUM> around third and fourth rollers <NUM> about which the endless belt <NUM> moves. In an exemplary embodiment, changing the effective length of the belt <NUM> between the first and second rollers <NUM> comprises moving the third roller <NUM> along the first arm <NUM>.

Although the subject of this disclosure has been described with reference to several embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the scope of the disclosure. In addition, any feature disclosed with respect to one embodiment may be included in another embodiment, and vice-versa. <NUM> having a circumference and a length, the assembly comprising an endless belt <NUM> and first and second rollers <NUM>. The endless belt <NUM> is configured to wrap partially around the circumference of the vessel <NUM> to contact and impart pressure on a filament winding <NUM> disposed on an outside surface of the vessel <NUM>. The endless belt <NUM> moves around the first and second rollers <NUM>. A space <NUM> is disposed between the first and second rollers <NUM> to allow passage of a filament wind eye <NUM> of the system configured to move in a reciprocal motion <NUM> along the length of the vessel <NUM>.

Claim 1:
An assembly configured for use in a system for forming filament windings (<NUM>) on a vessel (<NUM>) having a circumference and a length, the assembly comprising:
an endless belt (<NUM>) configured to wrap partially around the circumference of the vessel (<NUM>) to contact and impart pressure on a filament winding (<NUM>) disposed on an outside surface of the vessel (<NUM>); and
first and second rollers (<NUM>) about which the endless belt (<NUM>) moves;
characterised in that a space (<NUM>) is disposed between the first and second rollers (<NUM>) to allow a filament wind eye (<NUM>) of the system to move in a reciprocal motion along the length of the vessel (<NUM>).