Methods and devices for stabilization of shelves in a freeze-drying chamber

Abstract

The present disclosure relates to field of freeze-drying systems, and more particularly, to internal shelving components of freeze- drying chambers. A freeze-drying chamber comprises: a loading door configured to allow entry of samples into the freeze-drying chamber; a shelf-stack comprising a plurality of shelves configured to be adjusted and maintained vertically within the freeze-drying chamber along at least one vertical guide rail located in a rear region of the freeze-drying chamber opposite the loading door; and at least one backstop located near the loading door, the backstop configured to stabilize one of the plurality of shelves when at load height to prevent or reduce lateral and / or longitudinal movement of the shelf during loading.

Description

METHODS AND DEVICES FORSTABILIZATION OF SHELVES IN A FREEZE-DRYING CHAMBERCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority of U.S. Provisional Patent Application No. 63 / 748,624, filed January 23, 2025, the disclosure of which is hereby incorporated by reference herein in its entirety.TECHNICAL FIELD

[0002] The present disclosure relates to field of freeze-drying systems, and more particularly, to internal shelving components of freeze-drying chambers.BACKGROUND

[0003] Freeze-drying, also known as lyophilization or cryodesiccation, is a process used to remove water and / or other solvents from products. This process has numerous applications across various industries, including preserving perishable materials, facilitating transport of materials, manufacturing ceramics, and producing products with short reconstitution times while maintaining acceptable potency levels. Freeze-drying can be applied to many different materials, including food, pharmaceuticals, and biological specimens.

[0004] Production scale lyophilization is typically performed inside a chamber on a series of shelves. In certain systems, the shelves are capable of being raised and lowered, allowing the shelf pack to collapse into the lower portion of the chamber. This vertical adjustment can be achieved in certain freeze-drying systems by connecting the shelves with hanger rods. However, because the hanger rods can freely move vertically, there is often a considerable amount of clearance in each shelf. This clearance can result in the shelves rotating or otherwise moving out of alignment during various operations.

[0005] During loading operations, samples such as vials are pushed onto shelves using a loader with an extendable bridge plate. The loader is typically configured to fill a shelf with vials in a single loading operation. To combat misalignment between the loader and the shelves, chambers may include guide rails to prevent rotation and shelf guides to engage each rail and maintain alignment of the shelf as vials are received. However, the guide rails are primarily designed to constrain the shelves during vertical motion, and they may be insufficient to align the shelves with the bridge plate of the loader during loading operations.

[0006] The methods of constructing freeze-drying chambers can present challenges.Because the chamber is a large weldment and the features for mounting the guide rails are also welded, it can be difficult to accurately place the rails such that they are truly square to theloading door of the chamber. Further, the rails are not intended to provide support in the direction of loading. Glass vials can exert considerable amounts of force via friction as they are pushed onto the shelf, which can cause the guide rails to bow outwards and allow the shelf to push away from the bridge plate. This gap can induce misalignment, potentially leading to fallen vials, broken vials, and damage to the equipment.SUMMARY

[0007] The following summary presents a simplified summary of various aspects of the present disclosure in order to provide a basic understanding of such aspects. This summary is not an extensive overview of the disclosure. It is intended to neither identify key or critical elements of the disclosure, nor delineate any scope of the particular embodiments of the disclosure or any scope of the claims. Its sole purpose is to present some concepts of the disclosure in a simplified form as a prelude to the more detailed description that is presented later.

[0008] In one aspect, a freeze-drying chamber comprises: a loading door configured to allow entry of samples into the freeze-drying chamber; a shelf-stack comprising a plurality of shelves configured to be adjusted and maintained vertically within the freeze-drying chamber along at least one vertical guide rail located in a rear region of the freeze-drying chamber opposite the loading door; and at least one backstop located near the loading door, the backstop configured to stabilize one of the plurality of shelves when at load height to prevent or reduce lateral and / or longitudinal movement of the shelf during loading.

[0009] In a further aspect, a loader, configured for loading samples into a freeze-drying chamber, comprises: an extendable bridge plate configured for engaging with a shelf of the freeze-drying chamber when the shelf is at load height; and an alignment rail disposed on a lateral edge of the bridge plate, the alignment rail configured to engage an alignment tab of the shelf to prevent or reduce lateral movement of the shelf.

[0010] In a further aspect, a method of retrofitting a freeze-drying chamber to improve shelf stability during loading comprises: installing one or more backstops configured to stabilize a shelf when at load height to prevent or reduce lateral movement of the shelf during loading.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present disclosure is illustrated by way of example, and not by way of limitation in the figures of the accompanying drawings.

[0012] FIG. 1 A illustrates a cutaway view of a conventional freeze-drying chamber.

[0013] FIG. IB illustrates a close-up view of a portion of a shelf stack of the freeze-drying chamber of FIG. 1A.

[0014] FIG. 2 illustrates a top-down cutaway view of a chamber interior showing engagement between a shelf and a loader.

[0015] FIG. 3 illustrates a top-down cutaway view of a freeze-drying chamber during loading operations.

[0016] FIG. 4A illustrates a close-up isometric view of a backstop assembly located at load height near a front corner of a shelf stack, according to at least one embodiment of the present disclosure.

[0017] FIG. 4B illustrates a close-up isometric view of a vertical guide rail disposed in a rear portion of a freeze-drying chamber, according to at least one embodiment of the present disclosure.

[0018] FIG. 5 illustrates a top-down cutaway view of a freeze-drying chamber including modifications for shelf stabilization during loading operations, according to at least one embodiment of the present disclosure.DETAILED DESCRIPTION

[0019] Embodiments of the present disclosure relate to methods and devices for stabilizing shelves in a freeze-drying chamber during loading of samples, including methods of retrofitting freeze-drying chambers to include such devices. In at least one embodiment, a freeze-drying chamber comprises a loading door configured to allow entry of samples into the chamber, and a shelf-stack comprising a plurality of shelves configured to be adjusted and maintained vertically within the chamber along at least one vertical guide rail. One or more backstops may be provided and arranged in either a rear region or a front region of the chamber, which are configured to stabilize one of the plurality of shelves when at load height to prevent or reduce left-to-right (lateral) and / or back-to-front (longitudinal) movement of the shelf during loading. As used herein, the term “longitudinal” refers to a direction parallel to a loading direction into the chamber, and the term “lateral” refers to a direction perpendicular to the loading direction.

[0020] FIG. 1A illustrates a cutaway view of a freeze-drying chamber 100, revealing internal components thereof. The freeze-drying chamber 100 may be used for preserving perishable materials, making materials more convenient for transport, making ceramics, or producing products with short reconstitution time with acceptable potency levels. In some cases, the freeze-drying chamber 100 may be used for food, pharmaceuticals, and biological specimens.

[0021] The freeze-drying chamber 100 includes a chamber housing 102 that encloses the internal components of the freeze-drying chamber 100. A loading door 104 is positioned on one side of the chamber housing 102 and is configured to allow entry of samples into the chamber. A vertical guide rail 106 extends along the interior of the chamber housing 102. Due to the cutawayview, a guide rail on the opposite side of the chamber is obscured. A support structure 108 is positioned near the base of the chamber.

[0022] A shelf stack 110 is disposed within the freeze-drying chamber 100. The shelf stack 110 comprises a plurality of shelves configured to be adjusted and maintained vertically within the chamber along the vertical guide rail 106. As illustrated, the vertical guide rail 106 is located in a front region of the freeze-drying chamber 100 adjacent to the loading door 104. Collapsed shelves 112 are positioned in a lower portion of the chamber, forming a collapsed pack when not in use for loading. Upper shelves of the shelf stack 110 may be separated and positioned at load height during loading operations.

[0023] FIG. IB provides a close-up view of a portion of the shelf stack 110. A shelf 114 is shown with an alignment cone 116 extending from a front edge of the shelf 114 and a shelf guide 118 positioned along the vertical guide rail 106. Above the shelf 114, an additional shelf 124 is shown with an alignment cone 126 and a shelf guide 128. The shelf guides 118 and 128 may comprise a polymeric material, such as polytetrafluoroethylene (PTFE). The shelf guides 118 and 128 engage with the vertical guide rail 106 to maintain alignment of the shelves as they are adjusted vertically within the chamber. The shelves may be raised from the shelf stack 110 or lowered to a desired height within the chamber using motorized controls. The alignment cones 116 and 126 extend from the front edges of the respective shelves 114 and 124 to engage with a loader during sample loading operations, helping to maintain proper vertical alignment between the shelves and the loader. In some cases, the shelves may be connected with hanger rods. The hanger rods may freely move vertically, which allows the shelf stack 110 to collapse into the lower portion of the chamber. As the hanger rods can freely move vertically, there may be a significant amount of clearance in each shelf, which can result in the shelves rotating or otherwise moving out of alignment.

[0024] FIG. 2 illustrates a top-down cutaway view of a chamber interior showing engagement between a shelf 212 and a bridge plate 208 of a loader 200. The shelf 212 may be the same or similar as the shelves shown in FIGS. 1 A and IB. The loader 200 may be configured for loading samples into a freeze-drying chamber, such as the freeze-drying chamber 100 described with reference to FIGS. 1 A and IB. The loader 200 includes an extendable bridge plate 208 that is configured for engaging with the shelf 212 when the shelf 212 is at load height. The bridge plate 208 may engage alignment cones on the front of the shelf 212. The alignment cones on the shelf 212 may be the same or similar to the alignment cone 116 and the alignment cone 126 described with reference to FIG. IB.

[0025] The loader 200 includes a pusher 202 configured to push samples onto the shelf 212. In some cases, the pusher 202 may push vials 210 onto the shelf 212 through the bridge plate208. The vials 210 may be arranged in a dense pattern on the shelf 212 as the pusher 202 advances the vials 210 from the loader 200 onto the shelf 212. The loader 200 may include one or more servo-controlled arms. As shown in FIG. 2, the loader 200 includes a servo-controlled arm 204 and a servo-controlled arm 206. The servo-controlled arm 204 and the servo-controlled arm 206 may facilitate controlled movement during the loading process.

[0026] FIG. 3 illustrates a top-down cutaway view of a freeze-drying chamber 300, which may be the same or similar to the freeze-drying chamber 100. The freeze-drying chamber 300 may be the same or similar to the freeze-drying chamber 100 described with reference to FIGS.1 A and IB. During loading operations, a force from a pusher, such as the pusher 202 described with reference to FIG. 2, may be delivered along a loading direction 302 through a loading door 304. The loading door 304 may be the same or similar to the loading door 104 described with reference to FIG. 1A.

[0027] The freeze-drying chamber 300 includes a guide rail 306 and a guide rail 308 positioned at the front of the freeze-drying chamber 300 disposed on opposite sides of the loading door 304. The guide rail 306 and the guide rail 308 may be the same or similar to the vertical guide rail 106 described with reference to FIGS. 1 A and IB.

[0028] While the guide rail 306 and the guide rail 308 provide some stabilization along a front stabilization force direction 310 and a front stabilization force direction 312, rotation of a shelf 314 being loaded can occur as indicated by a rotation indicator 316. The shelf 314 may be the same or similar to the shelf 114 described with reference to FIGS. 1 A and IB.

[0029] The rotation can contribute to misalignment problems where the shelf 314 may move out of proper alignment with a bridge plate, such as the bridge plate 208 described with reference to FIG. 2, during loading. The guide rail 306 and the guide rail 308 are primarily used to constrain the shelves during vertical motion, and the guide rail 306 and the guide rail 308 may be insufficient to align the shelves with a bridge plate of a loader.

[0030] Methods of constructing the chamber may also contribute to misalignment. As the chamber is a large weldment and the features for mounting the guide rails are also welded, it may be difficult to accurately place the guide rail 306 and the guide rail 308 such that the guide rail 306 and the guide rail 308 are truly square to the loading door 304 of the chamber. Further, the guide rail 306 and the guide rail 308 are not intended to provide support in the direction of loading. Glass vials may exert significant amounts of force via friction as the glass vials are pushed onto the shelf 314. This can cause the guide rail 306 and the guide rail 308 to bow outwards, allowing the shelf 314 to push away from a bridge plate. This gap can induce misalignment leading to fallen vials, broken vials, and damage to the equipment.

[0031] FIG. 4A shows a close-up view of a backstop located at the load height near a front comer of the shelf stack, in accordance with at least one embodiment. The close-up view may correspond to a modified version of any of the aforementioned chambers, in particular the shelf stack 110 and supporting components. As shown, a bridge plate 402 engages a shelf 406 during loading operations. The bridge plate 402 may be the same or similar to the bridge plate 208 described with reference to FIG. 2. The shelf 406 may be the same or similar to the shelf 114 described with reference to FIGS. 1 A and IB, or the shelf 212 described with respect to FIG. 2.

[0032] In at least one embodiment, the bridge plate 402 includes a tapered alignment rail 404 positioned along an edge of the bridge plate 402. The tapered alignment rail 404 may be configured to engage components on the shelf 406, such as an alignment tab 408, to guide the shelf 406 laterally during alignment. In at least one embodiment, the bridge plate 402 may be modified or retrofitted to include the tapered alignment rail 404. The tapered alignment rail 404 may comprise a tapered engagement surface shaped to engage the alignment tab 408 of the shelf 406.

[0033] In at least one embodiment, the alignment tab 408 extends from a front corner of the shelf 406 near the loading door region. The alignment tab 408 extends past the front of the shelf 406 towards the loading door 104. In some cases, each of the plurality of shelves of the shelf stack 110 may comprise one or more alignment tabs that extend past the front of the shelf towards the loading door. The alignment tab 408 may be L-shaped as illustrated in FIG. 4A, or the alignment tab 408 may have another suitable geometry to facilitate engagement with the tapered alignment rail 404 and a guide pad. In at least one embodiment, the alignment tab 408 may comprise a tapered engagement surface for contacting a guide pad on a backstop. The alignment tab 408 may comprise a tapered edge to engage the tapered alignment rail 404 of the bridge plate 402 to guide the shelf 406 left-to-right before the bridge plate 402 locates the shelf 406 up against backstops.

[0034] In at least one embodiment, a guide pad 410 is mounted on a backstop 412. The guide pad 410 comprises a rounded surface and / or one or more tapered surfaces configured to engage the alignment tab 408 when the shelf 406 is at load height. The guide pad 410 may guide the shelf 406 into position longitudinally. In some cases, each alignment tab may be configured to engage the guide pad 410 when the corresponding shelf is at load height. In at least one embodiment, the guide pad 410 is formed from a plastic material, such as polytetrafluoroethylene. In at least one embodiment, the guide pad 410 may comprise other polymeric materials suitable for low-friction engagement with the alignment tab 408.

[0035] In at least one embodiment, the backstop 412 is located near the loading door 104. The backstop 412 may be configured to stabilize one of the plurality of shelves when at loadheight to prevent or reduce back-to-front (longitudinal) movement of the shelf during loading. The backstop 412 may be mounted to a backstop mounting panel 414, which allows for adjustment of the position of the backstop 412 front to back within the chamber. In at least one embodiment, the backstop 412 may be adjustable front to back.

[0036] The arrangement of the backstop 412, the guide pad 410, and the alignment tab 408 functions to stabilize the shelf 406 during loading operations by preventing or reducing longitudinal movement of the shelf 406 as samples (such as vial samples) are pushed onto the shelf 406 by a loader. The engagement between the alignment tab 408 and the guide pad 410 introduces stabilization forces that restrict rotation of the shelf 406, while the tapered alignment rail 404 assists in lateral alignment between the bridge plate 402 and the shelf 406. The tapered alignment rail 404 may be configured to engage the alignment tab 408 of the shelf 406 to prevent or reduce lateral movement of the shelf 406.

[0037] FIG. 4B shows a close-up view of a vertical guide rail 430 that has been relocated from the front region of the freeze-drying chamber to a rear region, in accordance with at least one embodiment. In at least one embodiment, the vertical guide rail 430 is coupled to a support structure 438. For example, the vertical guide rail 430 and the support structure 438 may correspond to the vertical guide rail 106 and the support structure 108, respectively, of FIGS. 1 A and IB. In at least one embodiment, one or more additional support structures, such as the support structure 436, may be present and mounted, for example, to a wall of the freeze-drying chamber.

[0038] In at least one embodiment, a method of retrofitting a freeze-drying chamber to improve shelf stability during loading may comprise installing one or more backstops configured to stabilize a shelf when at load height to prevent or reduce longitudinal movement of the shelf during loading. The method may further comprise installing alignment tabs on shelves of the freeze-drying chamber. The method may further comprise installing an alignment rail on a bridge plate of a loader, where the alignment rail is configured to engage the alignment tabs. The method may further comprise adjusting the position of the one or more backstops using backstop mounting panels. In some cases, the one or more backstops may comprise guide pads with tapered surfaces. In at least one embodiment, the method includes removing alignment rails (e.g., alignment rails 306 and 308) from the front of the chamber to provide space for the installation of backstops, and moving the alignment rails to a rear portion of the freeze-drying chamber.

[0039] FIG. 5 illustrates a top-down cutaway view of a freeze-drying chamber 500 that includes the modifications described with respect to FIGS. 4 A and 4B. The freeze-drying chamber 500 may be the same or similar to the freeze-drying chamber 100 described withreference to FIGS. 1 A and IB, with the addition of stabilization components. As illustrated, the shelf 406 is positioned within the freeze-drying chamber 500 and engages with the bridge plate 402 that includes the tapered alignment rail 404. Two backstops may be positioned on opposite sides of the loading door 104. On one side of the freeze-drying chamber 500, the backstop 412 is mounted to the backstop mounting panel 414 and includes the guide pad 410 configured to engage the alignment tab 408 extending from a front corner of the shelf 406, as described with respect to FIG. 4A. On the opposite side of the freeze-drying chamber 500, a similar backstop 422 is mounted to a backstop mounting panel 424 and includes a guide pad 420 configured to engage an alignment tab 418 extending from the opposite front comer of the shelf 406.

[0040] In at least one embodiment, the engagement of the guide pad 410 and the guide pad 420 with the alignment tab 408 and the alignment tab 418, respectively, introduces opposing longitudinal forces along a first front longitudinal stabilization direction 419 and a second front longitudinal stabilization direction 429. In at least one embodiment, engagement of the alignment tab 408 with the alignment rail 404 introduces a lateral stabilization force along a front lateral stabilization direction 416. In embodiments for which an additional alignment rail is disposed on the bridge plate opposite the alignment rail 404, this would introduce a lateral stabilization force along a front lateral stabilization direction 426. The opposing lateral forces and the longitudinal stabilization forces restrict rotation of the shelf 406.

[0041] As further shown in FIG. 5, the vertical guide rail 430 and an additional vertical guide rail 440 are positioned at the rear of the freeze-drying chamber 500. Similar to the vertical guide rail 430, the vertical guide rail 440 may have been retrofitted to the rear of the freeze-drying chamber 500. In at least one embodiment, one or more support structures, such as a support structure 446, may be present to provide support to the vertical guide rail 440. The vertical guide rails 430 and 440 add additional opposing lateral forces along a rear stabilization force direction 432 and a rear stabilization force direction 434, respectively. The additional opposing lateral forces along the rear stabilization force direction 432 and the rear stabilization force direction 434 further help mitigate rotation of the shelf 406.

[0042] In embodiments that utilize the aforementioned modifications, rotation of the shelf 406 (shown as rotation indicator 450) is reduced or eliminated when the bridge plate 402 is engaged to the shelf 406. The tapered alignment rail 404 on the bridge plate 402 guides the shelf 406 laterally before the bridge plate 402 engages the shelf 406. The presence of the alignment tab 408, the alignment tab 418, the guide pad 410, the guide pad 420, the backstop 412, the backstop 422, and the tapered alignment rail 404 adjusts the shelf 406 to mate with the bridge plate 402 with little to no vertical or horizontal (lateral or longitudinal) misalignment.

[0043] A method of retrofitting a freeze-drying chamber to improve shelf stability during loading may comprise installing the backstops at opposite sides of a loading door of the freeze-drying chamber. In some cases, the method may further comprise installing additional backstops at different heights to provide stabilization for collapsed shelves.

[0044] A loader configured for loading samples into the freeze-drying chamber 500 may comprise an extendable bridge plate (e.g., the bridge plate 402) to deliver samples into the freeze-drying chamber 500 and configured for engaging with a shelf (e.g., the shelf 406) when at load height. The bridge plate may comprise one or more alignment rails (e.g., the alignment rail 404) configured to engage an alignment tab (e.g., the alignment tab 408) of the shelf to prevent or reduce lateral movement of the shelf. In at least one embodiment, a method of retrofitting a freeze-drying chamber to improve shelf stability during loading may comprise retrofitting the freeze-drying chamber to include one or more backstops (e.g., the backstops 412 and 422).

[0045] The following illustrative embodiments are now described.

[0046] Embodiment 1: A freeze-drying chamber comprising: a loading door configured to allow entry of samples into the freeze-drying chamber; a shelf-stack comprising a plurality of shelves configured to be adjusted and maintained vertically within the freeze-drying chamber along at least one vertical guide rail located in a rear region of the freeze-drying chamber opposite the loading door; and at least one backstop located near the loading door, the backstop configured to stabilize one of the plurality of shelves when at load height to prevent or reduce lateral and / or longitudinal movement of the shelf during loading.

[0047] Embodiment 2: The freeze-drying chamber of Embodiment 1, wherein the backstop comprises a guide pad, the guide pad comprising one or more tapered surfaces to engage a shelf at load height.

[0048] Embodiment 3: The freeze-drying chamber of Embodiment 2, wherein the guide pad comprises polytetrafluoroethylene.

[0049] Embodiment 4: The freeze-drying chamber of either Embodiment 2 or Embodiment 3, wherein each of the plurality of shelves comprises one or more alignment tabs that extend past a front-facing edge of the shelf towards the loading door.

[0050] Embodiment 5: The freeze-drying chamber of Embodiment 3, wherein each alignment tab is configured to engage the guide pad when the corresponding shelf is at load height.

[0051] Embodiment 6: The freeze-drying chamber of either Embodiment 4 or Embodiment 5, wherein each alignment tab is L-shaped.

[0052] Embodiment 7: The freeze-drying chamber of any one of Embodiments 4-6, wherein each alignment tab comprises a tapered engagement surface for contacting the guide pad.

[0053] Embodiment 8: The freeze-drying chamber of any one of the preceding Embodiments, wherein the backstop is adjustable laterally or longitudinally.

[0054] Embodiment 9: The freeze-drying chamber of any one of the preceding Embodiments, wherein the backstop is mounted to a backstop mounting panel.

[0055] Embodiment 10: The freeze-drying chamber of any one of the preceding Embodiments, comprising two backstops disposed on opposite sides of the loading door.

[0056] Embodiment 11 : The freeze-drying chamber of any one of the preceding Embodiments, wherein the shelf-stack is connected to the at least one vertical guide rail via shelf guides.

[0057] Embodiment 12: The freeze-drying chamber of Embodiment 11, wherein the shelf guides comprise a polymeric material.

[0058] Embodiment 13: A loader configured for loading samples into a freeze-drying chamber, the loader comprising: an extendable bridge plate configured for engaging with a shelf of the freeze-drying chamber when the shelf is at load height; and an alignment rail disposed on a lateral edge of the bridge plate, the alignment rail configured to engage an alignment tab of the shelf to prevent or reduce lateral movement of the shelf.

[0059] Embodiment 14: The loader of Embodiment 13, wherein the alignment rail comprises a tapered engagement surface shaped to engage the alignment tab.

[0060] Embodiment 15: The loader of either Embodiment 13 or Embodiment 14, further comprising a pusher configured to push samples onto the shelf.

[0061] Embodiment 16: The loader of any one of Embodiments 13-15, further comprising one or more servo-controlled arms.

[0062] Embodiment 17: A method of retrofitting a freeze-drying chamber to improve shelf stability during loading, the method comprising: installing one or more backstops configured to stabilize a shelf when at load height to prevent or reduce lateral and / or longitudinal movement of the shelf during loading.

[0063] Embodiment 18: The method of Embodiment 17, wherein installing the one or more backstops comprises installing the backstops at opposite sides of a loading door of the freeze-drying chamber.

[0064] Embodiment 19: The method of either Embodiment 17 or Embodiment 18, wherein the one or more backstops comprise guide pads with tapered surfaces.

[0065] Embodiment 20: The method of any one of Embodiments 17-19, further comprising installing alignment tabs on shelves of the freeze-drying chamber.

[0066] Embodiment 21: The method of Embodiment 20, further comprising installing an alignment rail on a bridge plate of a loader, the alignment rail configured to engage the alignment tabs.

[0067] Embodiment 22: The method of any one of Embodiments 17-21, further comprising adjusting a position of the one or more backstops using backstop mounting panels.

[0068] Embodiment 23: The method of any one of Embodiments 17-22, further comprising installing additional backstops at different heights to provide stabilization for collapsed shelves.

[0069] Embodiment 24: A loader configured for loading samples into the freeze-drying chamber of any one of Embodiments 1-12, the loader comprising an extendable bridge plate to deliver samples into the freeze-drying chamber and configured for engaging with a shelf when at load height, the bridge plate comprising an alignment rail configured to engage an alignment tab of the shelf to prevent or reduce lateral movement of the shelf.

[0070] Embodiment 25: A method of retrofitting a freeze-drying chamber to improve shelf stability during loading, the method comprising retrofitting the freeze-drying chamber to include one or more backstops of any one of Embodiments 1-12.

[0071] In the foregoing description, numerous details are set forth. It will be apparent, however, to one of ordinary skill in the art having the benefit of this disclosure, that the present disclosure may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring the present disclosure.

[0072] The words “example” or “exemplary” are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the words “example” or “exemplary” is intended to present concepts in a concrete fashion. As used in this application, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise, or clear from context, “X includes A or B” is intended to mean any of the natural inclusive permutations. That is, if X includes A; X includes B; or X includes both A and B, then “X includes A or B” is satisfied under any of the foregoing instances. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from context to be directed to a singular form. Reference throughout this specification to “certain embodiments,” “one embodiment,” “at least one embodiment,” or the like means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase“certain embodiments,” “one embodiment,” “at least one embodiment,” or the like in various places throughout this specification are not necessarily all referring to the same embodiment.

[0073] The present disclosure is not to be limited in scope by the specific embodiments described herein. Indeed, other various embodiments of and modifications to the present disclosure, in addition to those described herein, will be apparent to those of ordinary skill in the art from the description and accompanying drawings. Thus, such other embodiments and modifications are intended to fall within the scope of the present disclosure. Further, while the present disclosure has been described in the context of a particular embodiment in a particular environment for a particular purpose, those of ordinary skill in the art will recognize that its usefulness is not limited thereto and that the present disclosure may be beneficially implemented in any number of environments for any number of purposes. Accordingly, the claims set forth below should be construed in view of the full breadth and spirit of the present disclosure as described herein, along with the full scope of equivalents to which such claims are entitled.

[0074] It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description. The scope of the disclosure should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

What is claimed is:

1. A freeze-drying chamber comprising:a loading door configured to allow entry of samples into the freeze-drying chamber; a shelf-stack comprising a plurality of shelves configured to be adjusted and maintained vertically within the freeze-drying chamber along at least one vertical guide rail located in a rear region of the freeze-drying chamber opposite the loading door; andat least one backstop located near the loading door, the backstop configured to stabilize one of the plurality of shelves when at load height to prevent or reduce lateral and / or longitudinal movement of the shelf during loading.

2. The freeze-drying chamber of claim 1, wherein the backstop comprises a guide pad, the guide pad comprising one or more tapered surfaces to engage a shelf at load height.

3. The freeze-drying chamber of claim 2, wherein each of the plurality of shelves comprises one or more alignment tabs that extend past a front-facing edge of the shelf towards the loading door.

4. The freeze-drying chamber of claim 3, wherein each alignment tab is configured to engage the guide pad when the corresponding shelf is at load height.

5. The freeze-drying chamber of claim 2, wherein the guide pad comprisespoly tetrafluoroethy 1 ene .

6. The freeze-drying chamber of claim 1, wherein the backstop is adjustable laterally or longitudinally.

7. The freeze-drying chamber of claim 1, wherein the backstop is mounted to a backstop mounting panel.

8. The freeze-drying chamber of claim 1, comprising two backstops disposed on opposite sides of the loading door.

9. The freeze-drying chamber of claim 3, wherein each alignment tab is L-shaped.

10. The freeze-drying chamber of claim 3, wherein each alignment tab comprises a tapered engagement surface for contacting the guide pad.

11. The freeze-drying chamber of claim 1, wherein the shelf-stack is connected to the at least one vertical guide rail via shelf guides.

12. The freeze-drying chamber of claim 11, wherein the shelf guides comprise a polymeric material.

13. A loader configured for loading samples into a freeze-drying chamber, the loader comprising:an extendable bridge plate configured for engaging with a shelf of the freeze-drying chamber when the shelf is at load height; andan alignment rail disposed on a lateral edge of the bridge plate, the alignment rail configured to engage an alignment tab of the shelf to prevent or reduce lateral movement of the shelf.

14. The loader of claim 13, wherein the alignment rail comprises a tapered engagement surface shaped to engage the alignment tab.

15. The loader of claim 13, further comprising a pusher configured to push samples onto the shelf.

16. The loader of claim 13, further comprising one or more servo-controlled arms.

17. A method of retrofitting a freeze-drying chamber to improve shelf stability during loading, the method comprising:installing one or more backstops configured to stabilize a shelf when at load height to prevent or reduce lateral and / or longitudinal movement of the shelf during loading.

18. The method of claim 17, wherein installing the one or more backstops comprises installing the backstops at opposite sides of a loading door of the freeze-drying chamber.

19. The method of claim 17, wherein the one or more backstops comprise guide pads with tapered surfaces.

20. The method of claim 17, further comprising installing alignment tabs on shelves of the freeze-drying chamber.

21. The method of claim 20, further comprising installing an alignment rail on a bridge plate of a loader, the alignment rail configured to engage the alignment tabs.

22. The method of claim 17, further comprising adjusting a position of the one or more backstops using backstop mounting panels.

23. The method of claim 17, further comprising installing additional backstops at different heights to provide stabilization for collapsed shelves.

24. A loader configured for loading samples into the freeze-drying chamber of any one of claims 1-12, the loader comprising an extendable bridge plate to deliver samples into the freeze-drying chamber and configured for engaging with a shelf when at load height, the bridge plate comprising an alignment rail configured to engage an alignment tab of the shelf to prevent or reduce lateral movement of the shelf.

25. A method of retrofitting a freeze-drying chamber to improve shelf stability during loading, the method comprising retrofitting the freeze-drying chamber to include one or more backstops of any one of claims 1-12.

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