Inflatable Article with Reduced Stress Concentrations

Abstract

The present invention relates to collapsible hoses and inflatable structures such as pneumatic actuators for water control gates that are manufactured on and incorporate into their structure a flexible internal mandrel with rounded edges. One face of the mandrel and all of its rounded edges separate from the inflatable membrane during pressurization, while the remaining face of the flexible mandrel remains bonded to the remaining face of the inflatable envelope. Sharp internal edges (in the deflated condition) and their associated stress concentrations (in the inflated condition) are thus eliminated.

Claims

1. An inflatable article comprised of an inflatable envelope and an internal elastomeric mandrel with at least one round edge, wherein the inflatable envelope and the internal elastomeric mandrel are bonded together over a portion of one face sufficient to secure the mandrel in a fixed position relative to the inflatable envelope during repeated inflated inflate and deflate cycles, and wherein said inflatable envelope is not bonded to the at least one round edge of the internal elastomeric mandrel.

2. The inflatable article of claim 1, wherein the inflatable article is a hose.

3. The inflatable article of claim 1 wherein the inflatable article is a pneumatic actuator for a spillway gate.

4. The inflatable article of claim 1; wherein the inflatable article is a toroidal tunnel seal.

5. The inflatable article of claim 1, wherein the inflatable article is a consumer device for flotation, water rescue or human comfort.

6. An elastomeric article comprised of a plurality of strain oriented layers plied together sequentially so as to obtain desired directional physical properties.

7. An elastomeric membrane comprised of a plurality of strain oriented layers of elastomeric compound plied together in alternating directions so as to obtain orthotropic elastic properties.

8. The elastomeric membrane of claim 6 utilized as an inflatable article or portion thereof.

9. The elastomeric membrane of claim 6 configured as a hose or portion thereof.

10. The membrane of claim 9 utilized as a spinal disk prosthesis or portion thereof.

11. An elastomeric membrane locally defining an x-y plane comprised of a plurality of strain oriented layers of elastomeric compound plied together so as to establish a predominately z axis orientation of the constituent polymer molecules.

12. The membrane of claim 9 utilized as a wear surface.

13. The membrane of claim 9 utilized as a friction surface.

14. The membrane of claim 9 utilized as the tread of a tire.

15. The membrane of claim 9 utilized as the wear surface of a power transmission belt.

16. The membrane of claim 9, utilized as the wear surface of footwear.

17. A water control gate deployed by one or more inflatable actuators and restrained against hydrostatic forces by restraining means separate from said inflatable actuator.

Description

4. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Note that the following drawings relate to one or more embodiments only and are not in any way to limit the invention, embodiments thereof, claims, or elements thereof. Other objects, advantages and capabilities of the present invention will become apparent as the description proceeds taken in conjunction with the following drawings in which:

[0044] FIG. 1 illustrates an inflated hose in accordance with the prior art.

[0045] FIG. 2a illustrates an inflated hose of prior art.

[0046] FIG. 2b illustrates the hose of FIG. 2a in its deflated configuration.

[0047] FIG. 3a illustrates a deflated hose of prior art.

[0048] FIG. 3b illustrates an edge detail of the hose of FIG. 3a.

[0049] FIGS. 4a, 4b, 4c and 4d illustrate a hose in accordance with the present invention.

[0050] FIG. 5 illustrates a hose in accordance with the present invention.

[0051] FIG. 6 illustrates a hose in accordance with prior art.

[0052] FIG. 7 illustrates a hose in accordance with the present invention.

[0053] FIGS. 8, 9, 10, 11, 12a, 12b, 13, 13b illustrates a drive-over water control gate in accordance with the present invention.

[0054] FIGS. 14 and 15 illustrate a drive over wave barrier gate in accordance with the present invention.

[0055] FIGS. 16 and 17 illustrate the bladder actuator of a drive-over gate actuator.

[0056] FIGS. 18a and 18b illustrate a hose in accordance with the present invention.

[0057] FIG. 19 illustrates a peristaltic pump hose in accordance with the present invention.

[0058] FIG. 19 illustrates another peristaltic pump hose in accordance with the present invention.

[0059] FIG. 21 illustrates a hose in accordance with the present invention.

[0060] FIGS. 22a, 22b, 23a, and 23b illustrate inflatable bladders in accordance with the present invention.

[0061] FIGS. 24, 25, 26 and 27 illustrate edges details of inflatable articles in accordance with the present invention.

[0062] FIGS. 28a and 28b illustrate an inflatable seal in accordance with the present invention.

5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0063] Referring to FIGS. 4a, 4b, 4c and 4 d, a hose is illustrated in its pressurized and depressurized configurations. Rubber mandrel 1 extends across the lower half of the circumference and along the length of the inflated hose of FIG. 4b and extends in planar form across the bottom half of and along the length of the depressurized hose of FIG. 4a. Rounded edges shown in FIGS. 4a and 4b of rubber mandrel support hose wall portion shown in FIGS. 4c and 4d against collapse under external pressure. Stress relief element 1 may be molded or extruded, for example, and cured or vulcanized prior to incorporation into the balance of the hose structure. In such case it may usefully serve as a mandrel on which the balance of the hose structure may be built and around which the balance of the hose structure may be cured. In accordance with prior art practice mandrel built hoses require removal of the mandrel after curing of the hose. In the case of small hoses lead or other low melting point metals, or solid salt may be used as mandrels later removed by melting or dissolution. Such methods are impractical for large diameter (500 mm diameter, for example) hoses, in which case steel tubes of lengths of perhaps 12 meters are used. The limited lengths of steel mandrels results in the need for closely spaced hose connections. Such hose connections are typically heavy, rigid, and expensive. A hose with a number of such connections is therefore ill-suited for efficiently coiling onto a spool. In accordance with at least one example of prior art, the hose body of circular cross section is itself is increased in diameter to match or exceed the hose coupling diameter so as to allow spooling of the hose with its couplings. Obviously such an arrangement provides a very poor ratio of hose length to spool size. Referring to FIG. 7, a hose in accordance with the present invention illustrated as it might be coiled onto a spool. Such a coiled hose is much more convenient to deploy than an assembly of many hoses which must be connected, sometimes under difficult conditions such as in a sub-sea environment.

[0064] The utility of the stress relief element 1 is not limited to mandrel built hoses. Extruded and unreinforced hoses may likewise be manufactured with a stress relief element incorporated into one half of the hose so as to limit both internal compressive forces and external tensile stresses within the structure of the unpressurized or externally pressurized hose and to prevent high internal tensile stresses on the interior of the pressurized hose that would otherwise occur in conjunction with high compressive stresses along the exterior of the pressurized hose.

[0065] Hoses used for peristaltic pumps are subject to many cycles of alternating internal pressure and external compression. Hoses in accordance with the present invention, with a stress relief elements along one half of the interior, for example, in combination with a uniform exterior hose thickness are particularly suited for use in conjunction with peristaltic pumps. The uniform thickness attribute is especially convenient for peristaltic pumps designed for use with prior art hoses. However, in accordance with a further aspect of this invention, a peristaltic pump may be configured to use hose with stress relief inserts as elsewhere described in this application which hose need not necessarily be of uniform thickness in its collapsed configuration.

[0066] In accordance with a further embodiment of this invention, an elastomeric mandrel may be formed and cured, or partially cured, as an initial manufacturing step. Said elastomeric mandrel may be subsequently incorporated into an inflatable article such as a hose, tire, or pneumatic actuator, or into a storage article such as a tank of medical storage bag. One function of the elastomeric mandrel is to allow the structure of the inflatable article to be assembled and cured around the said elastomeric mandrel. The use of an elastomeric mandrel in accordance with the present invention enables articles that are rounded in shape when inflated or filled to be assembled, cured, and stored in a flat configuration. The need for removable or dissolvable interior mandrels is thus eliminated.

[0067] A consequent desirable characteristic of articles which are cured in a flattened configuration is that they inherently return to a flat configuration when empty or deflated. Such a flat configuration is generally easier to store and transport.

[0068] Additionally, the flattened configuration results in thorough emptying of the article, this being an advantage in the case of valuable liquids or liquids that might result in spoilage, contamination, fire hazard, excess weight, or pollution if left in place. In the case of hoses, residual liquid can result in the inability of the hose to be tightly wound.

[0069] In accordance with a further aspect of the present invention, a hose or other elastomeric article may be constructed of alternating layers of orthotropically strain oriented polymer. In this manner, a structure may be created that can readily strain in shear to desirably distribute loads across the structure.

[0070] In accordance with a further aspect of this invention, strain oriented polymer may be oriented normal to a wear surface for maximization of wear life. The resulting structure results in long polymer chains being directly anchored into the main body of the structure, such as a tire, as opposed to being largely dependant on cross linking to resist wear.

[0071] In accordance with a further aspect of this invention, a removable mandrel portion, of cylindrical form, for example, may be used in conjunction with an elastomeric mandrel in order to establish an inflation channel and to facilitate the sequential connection of multiple actuators or storage articles. Such an arrangement is advantageous for actuators for flood control gates that must be installed on a street or on a parking garage ramp, for example, where installation of embedded pipes in the roadway would be expensive and inconvenient. Such an arrangement also eliminates the need for air connection blackouts in a roadway.

[0072] Referring to FIGS. 21 and 22, gate panel 3 is deployed by pressurizing air bladder 5 through air fitting 26 with air through inflation pipe 17. Gate panel 3 is maintained in position against hydrostatic pressure and wave pressure by membrane 15. Membrane 15 may be discontinuous, or may be a continuous member. A continuous member may usefully prevent surf-borne debris from impact and possibly puncturing air bladders 5. The angle 27 of the gate panel is preferably less than 90 degrees in order that waves are deflected back toward their source.