Patent Description:
Methods of applying a new tread to a new tire casing or retreading an old tire casing are used to extend the life of tires, particularly trucks and off-road vehicles. By applying a new tread to a used tire casing, the life of the tire casing is extended. Retreaded tires offer an economical and environmentally friendly alternative to new tires.

Applying a new cured tread to a tire casing includes first prepping the tire casing, which may involve the steps of removing any unwanted material on the tire casing surface for the tread by inspecting, repairing and buffing the tire casing to remove any oxidized rubber or remaining tread to thereby create a desired circumference on the tire casing. Once the tire casing has been prepared, the tire is built; i.e., a new tire tread is secured to the outer circumferential surface of the casing. There are two basic methods of securing a new tread to a tire casing: the hot cure method (also referred to as mold cure) and the cold cure method (also referred to as pre cure).

In the hot cure process, a green or uncured tread rubber is positioned around the outer circumferential surface of the tire casing of the prepared tire and the tire and green tread are then cured in a curing mold to permanently adhere the new tire tread to the tire casing. In the cold cure process, an uncured cushion rubber is applied over the prepared outer circumferential surface of the tire to act as a binding agent between the tire and the new tire tread, which has already been cured. The tire, including the new cured tread and cushion rubber, is then cured in a heating chamber or autoclave to permanently adhere the new tread to the tire casing.

An envelope may be positioned around the tire during the curing process of the cold cure method. The envelope is a flexible rubber case that fits over the tire casing and tire tread and may be secured at axially spaced radially inward ends to a rim. The envelope provides a seal around the tire casing and tire tread and may be connected to a vacuum that depressurizes the interior of the envelope during at least a portion of the curing process, which applies compressive forces to the tire tread against the tire casing.

Prior art documents relevant to the invention are patent documents <CIT>, <CIT>, <CIT>, as well as <NPL>).

The present disclosure generally describes an air evacuation system to provide a vacuum to and test a curing assembly. The air evacuation system can include pneumatic control logic with multiple timing cycles to set up a boundary on time length for testing any particular enclosure in addition to a preset length of time to directly test for leaks when a predetermined vacuum level is reached.

Some implementations include a system for leak testing an envelope for a tire assembly. The system may include a rim, an envelope sized to accommodate a green tire assembly and secured to the rim, a vacuum system in fluid communication with the envelope, and a controller. The controller may be configured to depressurize the envelope to a predetermined vacuum, compare a slope of vacuum over time to a predetermined value, and enable proceeding with a depressurization of the envelope responsive to determining the slope of the vacuum over time being less than or equal to the predetermined value.

In some implementations, the vacuum system may include a Venturi vacuum system. In some implementations, the controller may be further configured to activate an indicator responsive to determining the slope of the vacuum over time being more than the predetermined value. In some implementations, the indicator may be a warning lamp or an audible indicator. In some implementations, enabling proceeding with the depressurization of the envelope may include setting a parameter value. In some implementations, enabling proceeding with the depressurization of the envelope may include activating a switch to enable a button or other physical component to be actuated. In some implementations, the predetermined vacuum may be at or above -<NUM> kPa (-<NUM> psi). In some implementations, comparing the slope of the vacuum over time to the predetermined value may include accessing data indicative of one or more pressure sensor measurements. In some implementations, the predetermined value may be between -<NUM> Pa/s (-<NUM> psi per second) and -<NUM> kPa/s (-<NUM> psi/s). In some implementations, the vacuum system may be in fluid communication with several envelopes.

Some implementations include process for leak testing an envelope for a tire assembly. The process may include depressurizing an envelope containing a green tire assembly mounted to a rim to a predetermined vacuum using a vacuum system, comparing a slope of vacuum over time to a predetermined value, and enabling proceeding with a depressurization of the envelope responsive to determining the slope of the vacuum over time being less than or equal to the predetermined value or activating an indicator responsive to determining the slope of the vacuum over time being more than the predetermined value.

In some implementations, the vacuum system may include a Venturi vacuum system. In some implementations, the indicator may be a warning lamp or an audible indicator. In some implementations, the predetermined vacuum may be at or above -<NUM> kPa (-<NUM> psi). In some implementations, the vacuum system may be in fluid communication with several envelopes. In some implementations, enabling proceeding with the depressurization of the envelope may include activating a switch to enable a button or other physical component to be actuated.

Some implementations include an apparatus for leak testing an envelope for a tire assembly. The apparatus may include a vacuum system in fluid communication with an envelope and a controller. The envelope may be sized to accommodate a green tire assembly. The controller may be configured to depressurize the envelope to a predetermined vacuum, compare a slope of vacuum over time to a predetermined value, and enable proceeding with a depressurization of the envelope responsive to determining the slope of the vacuum over time being less than or equal to the predetermined value.

In some implementations, the vacuum system may include a Venturi vacuum system. In some implementations, the predetermined vacuum may be at or above -<NUM> kPa (-<NUM> psi).

Other features, aspects, and advantages of the disclosure will become apparent from the description, the drawings, and the claims, in which:.

In the description that follows, structures and features that are the same or similar as shown in the various views of the drawings are denoted by the same reference numerals throughout the several views for consistency and simplicity, but it should be appreciated that the various structures or features may differ that those shown.

Referring to <FIG>, a method of forming a new tire and/or a retreaded tire <NUM> may include any known conventional steps to prepare a tire casing <NUM> to receive a new tread. In one or more embodiments, the tire casing <NUM> may first be inspected to ensure that it is a good candidate for initial treading or retreading. In certain implementations, the tire casing <NUM> may be manually inspected by a technician. In the same or other implementations, the tire casing <NUM> may be inspected by non-destructive inspection equipment. For example, in certain implementations, tire inspection may be performed using X-Ray equipment that detects is foreign objects are lodged in the tire casing and other defects that may impact the suitability of the tire casing for initial treading or retreading.

In one or more embodiments, following the step of inspection, and assuming the tire casing <NUM> is deemed suitable for further processing and treading or retreading, the tire casing <NUM> may be buffed. Buffing involves the mechanical and/or chemical removal of any oxidation and/or remaining tread on the tire casing <NUM> and creates a desired outer profile <NUM>, which is the outer circumferential surface of the tire casing <NUM>, for receiving a new tread. Buffing may be performed by grinding equipment that removes remaining tread rubber from the tire casing <NUM>. In certain embodiments, the buffing equipment may be controlled by an electronic control system that may be programmed to create a desired circumference and casing profile <NUM>. <CIT> discloses suitable buffing equipment for use in the treading or retreading method.

In one or more implementations, the method of treading or retreading may include the step of repairing defects in the tire casing <NUM>. The repair work may be performed either prior to or after the step of buffing. In certain embodiments, the step of repairing defects may include filling holes such as, for example, nail holes, with an uncured rubber. The step of repairing the tire casing <NUM> may also include cleaning and filling other defects in the tire casing with uncured rubber. As will be appreciated by those skilled in the art, the uncured rubber used to repair defects in the tire casing <NUM> is cured during the curing process to permanently fill in the defects, and thereby prolong the useful life of the tire casing <NUM>.

In one or more implementations, the outer profile <NUM> of the tire casing <NUM> may receive a coating of cement once the buffing and repairs have been completed. In certain embodiments, the cement may be applied by spraying or by rolling. The cement provides a tacky surface for application of a cushion rubber, and any known rubber cements may be utilized in the method of the present invention. In one or more implementations, the cement may include rubber and vulcanizing agents dispersed in a solvent. In certain embodiments, the rubber cement may be allowed to dry following application so that the solvent can evaporate, leaving a thin film of tacky rubber on the outer circumferential surface of the tire carcass.

<CIT> discloses a suitable rubber cement for use in the retreading process of the present invention, and is incorporated herein by reference for that purpose. Rubber cements are available in a variety of forms and from a variety of commercial vendors, such as, for example: Fiber Bond Cement manufactured and sold by Patch Rubber Company, and ZEVOC® manufactured by APV Engineered Coatings (water-based cement). It is also contemplated that the process of the present disclosure may be performed without applying a cement.

Once the tire casing <NUM> has been prepped, a new tire tread <NUM> may be applied, which may be referred to as building the tire, to form a green tire assembly. In one or more embodiments, a layer of cushion rubber <NUM> is positioned between the outer circumferential surface <NUM> of the tire casing <NUM> and the tire tread <NUM>. In certain implementations, the cushion rubber <NUM> may be applied to an interior surface of the new tire tread <NUM> prior to positioning the tread on the tire casing <NUM>. In other implementations, the cushion rubber <NUM> may be applied directly to the outer circumferential surface <NUM> of the tire casing <NUM> prior to positioning of the new tire tread <NUM> on the casing. In one or more implementations, the cushion rubber <NUM> may be a strip of uncured rubber for bonding the cured tire casing <NUM> and the cured tread rubber <NUM> together. An example bonding system and method suitable for securing the new tire tread <NUM> to the tire casing <NUM> is disclosed in <CIT>.

In one or more implementations, the cushion rubber <NUM> may be formed from a rubber vulcanizate having a high percentage or amount of natural rubber or synthetic rubber, or blends thereof. Suitable types of synthetic rubbers include those made from conjugated dienes having generally from about <NUM> to about <NUM> carbon atoms and, preferably from about <NUM> to about <NUM> carbon atoms such as butadiene, isoprene, from conjugated dienes having from <NUM> to <NUM> carbon atoms with monomers of vinyl substituted aromatics having from <NUM> to <NUM> carbon atoms such as styrene, alpha-methylstyrene, and the like. Examples of suitable synthetic rubbers include polybutadiene, polyisoprene, and styrene-butadiene rubber. In certain implementations, the rubber may be compounded with conventional amounts of various additives such as, for example, oil, fillers, processing aids, zinc oxide, stearic acid, sulfur, various accelerators, antioxidants and antiozonants. <CIT> discloses a suitable cushion rubber.

In one or more implementations, the tire tread <NUM> may be formed from conventional tread rubber compositions, as are well known to those skilled in the art. In certain embodiments, the tire tread may include natural rubber, synthetic rubbers, or blends thereof. In one or more implementations, the tire tread <NUM> may include known additives such as, for example, oils, fillers, processing aids, zinc oxide, stearic acid, sulfur, various accelerators, antioxidants and antiozonants. In certain implementations, fillers may include carbon black and/or silica.

In one or more embodiments, the tire tread <NUM> may be substantially cured at the time of positioning the tread around the tire casing <NUM>. Those skilled in the art will appreciate that curing is a matter of degree, and that rubber articles that are not <NUM>% cured may still be referred to as cured or vulcanized. In one or more implementations, the tire tread may be at least <NUM>% cured when it is positioned around the tire casing, in other implementations at least <NUM>% cured, in other embodiments at least <NUM>% cured, and in still other implementations at least <NUM>% cured.

In one or more implementations, the tire tread <NUM> includes a band <NUM> that is generally planar and has a contact surface <NUM> that engages the cushion rubber and an outer surface <NUM> facing radially outwardly. A plurality of lugs <NUM> extend radially outwardly from the outer surface <NUM> of the band <NUM> to create a tread pattern on the outer circumferential surface of the tire <NUM>. In certain implementations, each of the lugs <NUM> may include a plurality of side surfaces 26a extending away from the band <NUM> and tire casing <NUM>, and an engagement surface 26b for contacting the ground.

Any number of lugs <NUM> in any desired sizes and shapes may be provided to produce innumerable tread patterns. The lugs <NUM> may have a height, as compared to the height of the band <NUM>, to provide the necessary traction and grip for the tire. The height of the band <NUM> and the lugs <NUM> refers to the radial distance between the contact surface <NUM> and the most distal radial point or surface of the lug <NUM>.

After positioning the tire tread <NUM> around the tire casing <NUM>, the tread may be spliced at longitudinal ends of the band <NUM> to form a continuous outer surface of the tire. Known rubber splicing materials and techniques may be employed to splice the opposing longitudinal ends of the tire tread <NUM> together. In certain embodiments, an adhesive may be applied to the longitudinal ends of the tire tread <NUM>, and an uncured strip of splice rubber may be positioned between the longitudinal ends of the tire tread <NUM>. As will be apparent to those skilled in the art, subsequent curing of the tire will create a continuous tire tread <NUM> and permanently secure the longitudinal ends of the tire tread <NUM> together.

In one or more implementations, a green tire assembly, including the tire casing <NUM>, cushion rubber <NUM>, and tread <NUM>, may be positioned within a rubber envelope <NUM> prior to curing. The adhesion between the tire casing <NUM> and the tread <NUM> has not been completed in the green tire assembly. In certain implementations, the cushion rubber <NUM> of the green tire assembly is substantially uncured.

The rubber envelope <NUM> includes an open end <NUM> facing an axis of rotation of the envelope <NUM>. The open end <NUM> is defined by opposing radial edges 34a and 34b, which are adapted to be positioned adjacent to the bead portions 36a and 36b of the tire casing <NUM>. Sidewalls <NUM> of the envelope extend radially from the radial edges 34a and 34b to an outer circumferential surface <NUM>. Thus, as will be appreciated by those skilled in the art, the envelope <NUM> has the same general shape as the green tire assembly. The envelope <NUM> is sized to fit snugly over the tread <NUM> and to allow the radial edges 34a and 34b to extend beyond the bead portions 36a and 36b of the tire casing <NUM>.

In one or more implementations, the envelope <NUM> may be spread to allow insertion of the green tire assembly. Any conventional devices and methods may be employed to spread the envelope <NUM> and position the green tire assembly within the spread envelope <NUM>. In certain implementations, the envelope <NUM> may be spread by a machine having a plurality of arms extending radially from the envelope <NUM>, the arms adapted to engage one of the radial edges 34a or 34b and stretch the envelope <NUM> radially outwardly to enlarge the diameter of the opening of the open end <NUM> defined by the radial edge. Following insertion of the green tire assembly, the arms are adapted to release the radial edges 34a or 34b to allow the envelope <NUM> and the radial edges 34a or 34b to return to their respective original positions.

In one or more implementations, the envelope <NUM> includes a plurality of recesses <NUM> extending radially outwardly from the outer circumferential surface <NUM>. In certain embodiments, the recesses <NUM> may each be sized and shaped to receive a lug <NUM> therein. Accordingly, the dimensions of each of the recesses <NUM> are substantially similar to but slightly larger than the dimensions of the lugs <NUM> to be received therein. The number and spacing of the recesses <NUM> may conform to the number and spacing of the lugs <NUM> so that each recess <NUM> receives a single lug <NUM> therein. In certain embodiments, each recess <NUM> may include side surfaces 38a extending radially outwardly from the outer circumferential surface <NUM> and a distal surface 38b corresponding to the side surfaces 26a and engagement surfaces 26b of the lugs <NUM>, respectively. As a result, the envelope <NUM> has substantially the same outer profile as the tire tread <NUM> prior to depressurization of the envelope, as discussed below.

In one or more implementations, the green tire assembly and envelope <NUM> may be mounted on a rim <NUM> following insertion of the green tire assembly into the envelope <NUM>. The envelope <NUM> is secured between the green tire assembly and the rim <NUM> adjacent to the bead portions 36a and 36b and the radial edges 34a and 34b. As will be discussed in greater detail below in reference to <FIG>, a leak testing process <NUM> may be implemented to test the seal of the envelope <NUM>.

According to the claimed invention, the tire casing <NUM> is then inflated by an inflation tube (not shown), to create an increased pressure within the tire and exert a sealing pressure between the green tire assembly, the envelope <NUM>, and the rim <NUM>. As will be understood by those skilled in the art, the interior of the envelope <NUM> is sealed at the rim <NUM> by virtue of the internal pressure within tire casing <NUM> to create an inner space between the envelope <NUM> and the green tire assembly. When mounted on the rim <NUM>, the green tire assembly and envelope <NUM> may be referred to as a tire assembly <NUM>.

In one or more implementations, the tire assembly <NUM> may be transported to a curing environment following mounting of the green tire assembly and envelope <NUM> on the rim <NUM>. In certain implementations, the curing environment may be, for example, an autoclave or pressure vessel in which the temperature and pressure are controlled. In one or more implementations, a plurality of tire assemblies <NUM> may be placed in the curing environment together to allow for simultaneous curing of the assemblies <NUM>. In certain implementations, a heated and/or pressurized curing medium, such as, for example, air, water, steam, or a combination thereof, may be introduced into the curing environment to simultaneously press the tire tread <NUM> against the tire casing <NUM> and cure the cushion rubber <NUM> positioned therebetween. Upon exiting the curing environment, the green tire assembly is converted to a treaded or retreaded tire <NUM>, with the cushion rubber <NUM> substantially cured and creating a permanent bond between the tire casing <NUM> and the tire tread <NUM>.

In one or more implementations, the curing medium within the curing environment (e.g. air or steam) may create a pressure within the curing environment of at least <NUM>/cm<NUM>, in other implementations a pressure of at least <NUM>/cm<NUM>, in still other implementations a pressure of at least <NUM>/cm<NUM>, and in yet other implementations a pressure of at least <NUM>/cm<NUM>.

In one or more implementations, the curing medium within the curing environment (e.g. air or steam) may create a temperature within the curing environment of at least <NUM>° C. , in other implementations a temperature of at least <NUM>° C. , in still other implementations a temperature of at least <NUM>° C. , and in yet other implementations a temperature of at least <NUM>° C.

In one or more implementations, the tire assembly <NUM> may remain in the curing environment for at least <NUM> hours, in other implementations at least <NUM> hours, in still other implementations at least <NUM> hours, and in yet other implementations at least <NUM> hours.

In one or more implementations, the envelope <NUM> may include a valve <NUM> that allows fluid to flow from one side of the envelope <NUM> to the other. The valve <NUM> may be any known and conventional valve for suitable for transfer of gasses, and may be manufactured as an integral component of the envelope <NUM>. The valve <NUM> communicates with the inner space between the envelope <NUM> and tire <NUM>.

In one or more embodiments, the valve <NUM> may be connected to and in fluid communication with a vacuum source <NUM> to depressurize the envelope <NUM> and reduce or substantially eliminate air within the envelope <NUM> of the tire assembly <NUM> and between the envelope <NUM> and the tire tread <NUM> and/or tire casing <NUM>. In one or more implementations, the envelope <NUM> may be depressurized throughout the curing process. In other implementations, the envelope <NUM> may be depressurized for at least a portion of the curing process.

As will be apparent to those skilled in the art, the inclusion of recesses <NUM> in the envelope <NUM> allows for an intimate relationship between the envelope <NUM> and tread <NUM> across substantially all of the surface area of the lugs <NUM>. This intimate relationship prevents deformation of the lugs <NUM> in the pressurized curing environment, and reduces the amount of air remaining within the envelope to improve the bond between the tread <NUM> and the tire casing <NUM> of the retreaded tire. <CIT> discloses suitable retread curing equipment and methods. In some implementations, the envelope <NUM> omits the recesses <NUM> and can be a singular envelope <NUM> for encasing the tire tread <NUM>, tire casing <NUM>, and cushion rubber <NUM> therein.

Following curing, the tire assembly <NUM> may be removed from the curing environment, and the valve <NUM> may be opened to allow air to reenter the inner space of the envelope <NUM>. In one or more implementations, the tire <NUM>, with the tread <NUM> permanently adhered thereto, and the envelope <NUM> may then be removed from the rim <NUM>. In certain implementations, the tire <NUM> may then be inspected to ensure that the tire tread <NUM> is properly secured to the tire casing <NUM>. In one or more implementations, excess tread rubber may be removed and the tire <NUM> may be painted and readied for subsequent use.

In an alternative implementation, the lugs <NUM> may be provided as separate and discrete components, rather than as projections from the band <NUM>. In these implementations, method of forming a tire <NUM> may include positioning the lugs <NUM> within the recesses <NUM> before or after insertion of a tire casing <NUM>, cushion rubber <NUM>, and/or tread band <NUM> within the envelope <NUM>. In certain implementations, the recesses <NUM> may be sized and shaped so as to impart a compressive force on the lugs <NUM> upon insertion, thereby maintaining the lugs <NUM> within the recesses <NUM> following insertion. The recesses <NUM> may be adapted to conform to the shape of the lugs <NUM>.

In one or more implementations, a tire casing <NUM> may be positioned within an envelope <NUM> having recesses <NUM> containing lugs <NUM> therein. In certain implementations, the tire casing <NUM> may have a cushion rubber <NUM> disposed on an outer circumferential surface thereof when inserted into the envelope <NUM> to facilitate adhesion of the lugs <NUM> to the tire casing <NUM>. In certain implementations a tread band <NUM> having a generally planar sectional profile may be positioned over the cushion rubber <NUM>, and a second layer of cushion rubber may be provided over the tread band <NUM>. In one or more implementations, a rubber cement and/or cushion rubber may be applied to a contact surface of the lugs <NUM> before or after insertion of the lugs <NUM> into the recesses <NUM> to facilitate bonding of the lugs to the tire casing <NUM>, tread rubber <NUM>, or cushion rubber <NUM>.

Following insertion of the lugs <NUM> into the recesses <NUM> and positioning of a tire casing <NUM>, cushion rubber <NUM>, and optionally a tread band <NUM> and a second layer of cushion rubber within the envelope <NUM>, the method of forming the retreaded tire proceeds as discussed above. A tire assembly <NUM> is formed with a rim <NUM>, and the tire assembly is cured. The depressurization of the envelope causes the lugs <NUM> to contact the exposed outer circumferential surface of the prepared tire casing, and the cushion rubber therebetween acts to permanently bond the lugs <NUM> to the tire casing. The correspondingly shaped lugs <NUM> and recesses <NUM> allow for removal of substantially all of the air between the tire casing <NUM> and the envelope <NUM> upon depressurization of the envelope.

<FIG> depicts an example system <NUM> depicting the tire assembly <NUM>, a vacuum system <NUM>, and a controller <NUM>. The vacuum system may include the vacuum source <NUM> of <FIG> and may be selectively coupleable to the valve <NUM> and/or another component in fluid communication with the valve <NUM>. The tire assembly <NUM> includes an envelope <NUM> that is in fluid communication with the vacuum system <NUM> to depressurize and remove any air from the envelope <NUM>. In some implementations, the vacuum system <NUM> includes a Venturi vacuum pump that uses air pressure from an air source (not shown) to create a vacuum to depressurize the envelope <NUM>. The vacuum system <NUM> is electrically and communicably coupled to a controller <NUM>. The controller is configured to control the vacuum system <NUM> to depressurize the envelope <NUM> and to perform a leak testing process <NUM> described in greater detail in reference to <FIG>. The controller <NUM> can be a programmable logic controller (PLC) to selectively open one or more valves of the vacuum system <NUM> and/or to control other components, such as a warning lamp <NUM> or other indicator. In some implementations, the warning lamp <NUM> may instead or additionally be an audible indicator, such as a horn or buzzer.

In some implementations, the vacuum system <NUM> can be coupled to several envelopes <NUM> of several tire assemblies <NUM> sequentially or in parallel via a manifold. For instance, a manifold may have a single selectively fluidly coupleable inlet and several outlets in fluid communication with the valves <NUM> of several envelopes <NUM>. In some implementations, several vacuum systems <NUM> may be coupled to the controller <NUM>. In some implementations, the controller <NUM> may be electronically or communicably to one or more other components, such as disable circuitry that disables the vacuum system <NUM> from operating above a predetermined level if the controller <NUM> determines that a leak is present in one or more envelopes fluidly coupled to the vacuum system <NUM>.

<FIG> depicts an implementation of a leak testing process <NUM> that can be performed by the controller <NUM> for leak testing one or more envelopes <NUM> in fluid communication with the vacuum system <NUM>. The method <NUM> includes fluidly coupling one or more envelopes <NUM> to one or more vacuum systems <NUM> (block <NUM>). In some implementations, the fluid coupling may include attaching a tube to a valve or a connector of the envelope <NUM> and/or a tube of the envelope <NUM> to a valve or connector of the one or more vacuum systems <NUM>. As noted above, in some implementations, the fluid coupling may be via a manifold for systems coupled to multiple envelopes <NUM>. The fluid coupling may be performed manually or may be automated (e.g., the controller <NUM> or another controller may automatically attach a tire assembly <NUM> to the vacuum system <NUM>).

The process <NUM> includes inflating or depressurizing the one or more envelopes to a predetermined pressure (block <NUM>). The vacuum system <NUM> and/or another system may be used to inflate the one or more envelopes to the predetermined pressure. In some implementations, such as a Venturi vacuum system, an air pressure supply source for the venture vacuum pump can be rerouted, such as through a valve, to provide an air supply into the one or more envelopes <NUM> that are fluidly coupled to the vacuum system <NUM>. In other implementations, a separate air supply source may be used to provide air to inflate the one or more envelopes. In other implementations, the vacuum system <NUM> and/or another system may be used to depressurize or apply a vacuum to the one or more envelopes <NUM> to the predetermined vacuum pressure.

The predetermined pressure may be a low pressure, such as <NUM> kPa (<NUM> psi) or below, to inflate the one or more envelopes for leak testing, but not overinflate and/or burst the one or more envelopes if a leak or improper attachment of the one or more envelopes <NUM> occurs. In some implementations the predetermined pressure can be between <NUM>,<NUM> kPa (<NUM> psi), inclusive, and <NUM> kPa (<NUM> psi), inclusive. In other implementations, the predetermined pressure may be a low negative pressure or vacuum, such as -<NUM> kPa (-<NUM> psi) or above, to depressurize the one or more envelopes for leak testing. In some implementations the predetermined pressure can be between <NUM> kPa (-<NUM> psi), inclusive, -<NUM>,<NUM> kPa (-<NUM> psi), inclusive.

The process <NUM> further includes comparing a slope of a pressure reading over time to a predetermine value (block <NUM>). The controller <NUM> and/or the vacuum system <NUM> can be communicably coupled to a pressure sensor to detect a pressure within the one or more envelopes <NUM> and/or of a tube or fluid line in fluid communication with the one or more envelopes <NUM>. In some implementations, one or more detected pressure readings can be stored in a computer readable storage medium, such as a random access memory of the controller <NUM>. In some implementations, a single pressure reading is acquired and the predetermined pressure above is stored as an initial pressure measurement.

For instances where a positive inflation pressure is applied, if the slope of the pressure reading over a period of time, such as one second, is less than the predetermined value, then the controller <NUM> is configured to determine there is a leak in the one or more envelopes and/or one or more of the envelopes is improperly mounted. That is, the controller <NUM> can access data indicative of one or more pressure sensor measurements, either from a pressure sensor directly or from the computer readable storage medium, and determine the slope of the pressure reading over the period of time, such as (P<NUM>-P<NUM>)/t.

The process <NUM> can proceed to activating the warning lamp <NUM> (block <NUM>) and/or another indicator or process responsive to the determination of a leak or improper mounting of the one or more envelopes. If the slope of the pressure reading over a period of time, such as one second, is more than or equal to the predetermined value, then the controller <NUM> is configured to determine there is no leak in the one or more envelopes and/or the one or more of the envelopes are properly mounted In some implementations, the predetermined value may be between <NUM> Pa/s (<NUM> psi per second), inclusive, and <NUM> kPa/s (<NUM> psi per second), inclusive. In some implementations, the predetermined value may be <NUM> kPa/s (<NUM> psi per second).

If the controller <NUM> determines there is no leak based on the slope being more than or equal to the predetermined value, then the process <NUM> can proceed to enabling the system to proceed with depressurizing the envelope <NUM> (block <NUM>). In some implementations, enabling the system to proceed may include setting a flag or a value for a parameter such that one or more enablement conditions for another process may be satisfied. For instance, if the controller <NUM> determined that there is no leak and/or the one or more envelopes are properly mounted, then a parameter value enabling a depressurization process to proceed may be set. In other implementations, the controller <NUM> may activate a switch to enable a button or other physical component to be actuated, such as an activate button to proceed with the depressurization when pushed by a person monitoring the system. In other implementations, the controller <NUM> may automatically proceed with a depressurization process to depressurize the one or more envelopes. In some implementations, the process <NUM> may occur for each cycle for depressurization of one or more envelopes.

For instances where a negative depressurization vacuum is applied, if the slope of the pressure reading over a period of time, such as one second, is less than the predetermined value, then the controller <NUM> is configured to determine there is a leak in the one or more envelopes and/or one or more of the envelopes is improperly mounted. In some implementations, the predetermined value may be between -<NUM> Pa/s (-<NUM> psi per second), inclusive, and -<NUM> kPa/s (-<NUM> psi per second), inclusive. In some implementations, the predetermined value may be -<NUM> kPa/s (-<NUM> psi per second). In some implementations, the negative depressurization vacuum is applied and, if a vacuum of <NUM> kPa (<NUM> inches of Hg) holds for ten seconds, then the controller <NUM> is configured to determine there is no leak in the one or more envelopes and/or one or more of the envelopes is properly mounted.

If the controller <NUM> determines there is no leak based on the slope being more than or equal to the predetermined value, then the process <NUM> can proceed to activating the warning lamp <NUM> (block <NUM>) and/or another indicator or process responsive to the determination of a leak or improper mounting of the one or more envelopes. If the slope of the pressure reading over a period of time, such as one second, is more than or equal to the predetermined value, then the controller <NUM> is configured to determine there is no leak in the one or more envelopes and/or the one or more of the envelopes are properly mounted. The process <NUM> can proceed to enabling the system to proceed with depressurizing the envelope <NUM> (block <NUM>). In some implementations, enabling the system to proceed may include setting a flag or a value for a parameter such that one or more enablement conditions for another process may be satisfied. For instance, if the controller <NUM> determined that there is no leak and/or the one or more envelopes are properly mounted, then a parameter value enabling a depressurization process to proceed may be set. In other implementations, the controller <NUM> may activate a switch to enable a button or other physical component to be actuated, such as an activate button to proceed with the depressurization when pushed by a person monitoring the system.

In other implementations, the controller <NUM> may automatically proceed with a depressurization process to depressurize the one or more envelopes. In some implementations, the process <NUM> may occur for each cycle for depressurization of one or more envelopes.

The term "controller" encompasses all kinds of apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, a system on a chip, or multiple ones, a portion of a programmed processor, or combinations of the foregoing. The apparatus can include special purpose logic circuitry, e.g., an FPGA or an ASIC. The apparatus and execution environment can realize various different computing model infrastructures, such as distributed computing and grid computing infrastructures.

While this specification contains many specific implementation details, these should not be construed as limitations on the scope of what may be claimed, but rather as descriptions of features specific to particular implementations.

As utilized herein, the term "substantially" and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the invention as recited in the appended claims.

The terms "coupled" and the like as used herein mean the joining of two components directly or indirectly to one another. Such joining may be stationary (e.g., permanent) or moveable (e.g., removable or releasable). Such joining may be achieved with the two components or the two components and any additional intermediate components being integrally formed as a single unitary body with one another or with the two components or the two components and any additional intermediate components being attached to one another.

The terms "fluidly coupled," "in fluid communication," and the like as used herein mean the two components or objects have a pathway formed between the two components or objects in which a fluid, such as water, air, gaseous reductant, gaseous ammonia, etc., may flow, either with or without intervening components or objects. Examples of fluid couplings or configurations for enabling fluid communication may include piping, channels, or any other suitable components for enabling the flow of a fluid from one component or object to another.

Claim 1:
A system (<NUM>) for leak testing an envelope (<NUM>) for a tire assembly (<NUM>, <NUM>, <NUM>; <NUM>), the system (<NUM>) comprising:
an envelope (<NUM>) sized to accommodate a green tire assembly (<NUM>, <NUM>, <NUM>; <NUM>);
a vacuum system (<NUM>, <NUM>) in fluid communication with the envelope (<NUM>); and
a controller (<NUM>) configured to:
depressurize (<NUM>) the envelope (<NUM>) to a predetermined vacuum;
compare (<NUM>) a slope of vacuum over time to a predetermined value;
enable (<NUM>) proceeding with a depressurization of the envelope (<NUM>) responsive to determining the slope of the vacuum over time being less than or equal to the predetermined value;
characterized in that it further comprises
a rim (<NUM>), wherein the envelope (<NUM>) is secured to the rim; and
an inflation tube, configured to inflate a tire casing (<NUM>), part of the green tire assembly (<NUM>, <NUM>, <NUM>; <NUM>), to create an increased pressure within the tire casing (<NUM>) and exert a sealing pressure between the green tire assembly (<NUM>, <NUM>, <NUM>; <NUM>) the envelope (<NUM>) and the rim (<NUM>).