Retractable guard assembly for casters

Abstract

Certain embodiments disclosed herein provide a retractable guard assembly (104) coupled to a caster of a mobile device and comprising a housing (208) and one or more guards (210, 212) disposed at least partially within the housing. The one or more guards are coupled for independent movement relative to the housing. The retractable guard assembly further comprises one or more corresponding biasing elements (330, 332) coupled to the one or more guards and the housing for biasing the one or more guards toward a fully deployed state. When the one or more guards are in a fully deployed state, contact between a fixed object and a portion of the one or more guards disposed outside the housing transitions the one or more guards to a retracted state, and when the contact is removed, the corresponding one or more biasing elements transition the one or more guards to a fully deployed state.

Description

TECHNICAL FIELD

[0001] Claim of Priority This application claims the benefit of priority of U.S. Provisional Patent Application No. 63 / 217,390, filed on July 1, 2021, entitled "RETRACTABLE GUARD ASSEMBLIES" by inventor Brandon L. Spoelstra, the entire disclosure of which is hereby incorporated herein by reference as if fully and completely set forth in the present specification.

[0002] The present disclosure generally relates to retractable guard assemblies for use in connection with casters of movable equipment, such as medical or non-medical equipment. BACKGROUND ART

[0003] Many types of equipment, particularly medical equipment, are provided with rotatable caster wheels so that they can be made movable and moved from place to place. For example, this movability allows medical staff to move the medical equipment around within an operating room, between operating rooms, between floors (e.g., using an elevator), and the like. However, in some cases, equipment (e.g., medical equipment) traveling on caster wheels may get caught when riding over electrical cables, fluid hoses, and other similar objects. This is cumbersome for the equipment operator and reduces the maneuverability of the equipment. Furthermore, this may cause the equipment to tip over, damage electrical cables, pinch and block hoses, and lead to other similar problems.

[0004] In some cases, certain existing cable guards are used with casters to push aside cables and hoses to prevent equipment from riding over them and causing the problems described above. However, existing cable guards create certain further undesirable problems. For example, when moving equipment over fixed obstacles such as door sills and elevator sills, or non-fixed but difficult-to-move obstacles such as floor mats, some existing cable guards must be removed and stored. However, forcing equipment operators to remove and store the cable guards every time they need to move equipment over such objects is an extremely burdensome task for them.

[0005] Some other existing cable guards are fixed in place, making them impossible to remove if you try to move equipment over a fixed obstacle. As a result, the fixed cable guards can get caught on such obstacles and cause the equipment to tip over. [Overview of the project] [Means for solving the problem]

[0006] This disclosure relates to a retractable guard assembly for use in connection with casters of mobile devices, such as medical devices or non-medical devices, in general.

[0007] Certain embodiments disclosed herein provide a retractable guard assembly coupled to a caster of a movable device, comprising a housing and one or more guards at least partially located within the housing. The one or more guards are coupled to the housing so as to be independently movable. The retractable guard assembly further comprises one or more corresponding biasing elements coupled to the one or more guards and the housing for biasing one or more guards toward a fully extended state. When one or more guards are in a fully extended state, contact between a fixed object and a portion of one or more guards located outside the housing causes one or more guards to move toward a retracted state. When one or more guards are in a retracted state and that contact is removed, the corresponding biasing elements cause one or more guards to move toward a fully extended state. In the fully extended state, one or more guards have a first clearance from the ground. In the retracted state, one or more guards have a second clearance from the ground, the second clearance being greater than the first clearance.

[0008] A particular embodiment disclosed herein provides a caster assembly for a movable device, comprising a caster having a caster wheel and a retractable guard assembly coupled to the caster. The retractable guard assembly comprises a housing and one or more guards at least partially located within the housing. The one or more guards are coupled to the housing so as to be independently movable. The retractable guard assembly further comprises one or more corresponding biasing elements coupled to the one or more guards and the housing for biasing one or more guards toward a fully extended state. When one or more guards are in a fully extended state, contact between a stationary object and a portion of one or more guards located outside the housing causes one or more guards to move toward a retracted state. When one or more guards are in a retracted state and that contact is removed, the corresponding biasing elements cause one or more guards to move toward a fully extended state. In the fully extended state, one or more guards have a first clearance from the ground. In the retracted state, one or more guards have a second clearance from the ground, the second clearance being greater than the first clearance.

[0009] The following description and related drawings detail specific exemplary features of one or more embodiments.

[0010] The accompanying drawings illustrate specific aspects of one or more embodiments and should not be considered to limit the scope of this disclosure. [Brief explanation of the drawing]

[0011] [Figure 1] This disclosure shows a medical device comprising four caster assemblies according to a specific embodiment of this disclosure. [Figure 2A] Figure 1 shows a side view of a caster assembly, including a retractable guard assembly in an unfolded state, according to a particular embodiment of the present disclosure. [Figure 2B] Figure 2A shows a perspective view of the caster assembly according to a specific embodiment of the present disclosure. [Figure 2C] Figure 2B shows a perspective view of a caster assembly, including a retractable guard assembly with the front guard in a retracted position, according to a particular embodiment of the present disclosure. [Figure 3A] Figures 2A to 2C show exploded views of a caster assembly according to a specific embodiment of the present disclosure. [Figure 3B] These represent assumed dimensions shown for a cross-section of an embodiment of a caster assembly according to a particular embodiment of the present disclosure. [Figure 3C] These represent assumed dimensions shown for a cross-section of an embodiment of a caster assembly according to a particular embodiment of the present disclosure. [Figure 4A] The image shows an internal side view of the front guard and rear guard in their deployed state, according to a particular embodiment of the present disclosure. [Figure 4B] Figure 4A shows an inside side view of the front guard in a retracted state, according to a particular embodiment of the present disclosure. [Figure 5A] This illustrates the movement of the forward guard in Figure 4A while in contact with a stationary object and subsequently while moving over that object, according to a particular embodiment of the present disclosure. [Figure 5B] This illustrates the movement of the forward guard in Figure 4A while in contact with a stationary object and subsequently while moving over that object, according to a particular embodiment of the present disclosure. [Figure 5C] This illustrates the movement of the forward guard in Figure 4A while in contact with a stationary object and subsequently while moving over that object, according to a particular embodiment of the present disclosure. [Figure 5D] This illustrates the movement of the forward guard in Figure 4A while in contact with a stationary object and subsequently while moving over that object, according to a particular embodiment of the present disclosure. [Modes for carrying out the invention]

[0012] To facilitate understanding, the same reference numerals are used whenever possible to indicate the same elements common to multiple drawings. The elements and features of one embodiment are intended to be usefully incorporated into other embodiments without further explanation.

[0013] Certain embodiments of this disclosure provide retractable guard assemblies which may be used in conjunction with casters of mobile devices. The following embodiments describe retractable guard assemblies which are mounted on casters and used in conjunction with medical devices such as ophthalmic surgical consoles, but it will be understood by those skilled in the art that the retractable guard assemblies described herein may be used in conjunction with a variety of medical and non-medical devices. Examples of such medical devices include surgical and non-surgical consoles, diagnostic equipment, hospital beds, hospital carts, stretchers, IV (intravenous) poles, and other mobile medical devices. Examples of non-medical devices include any mobile, electric and / or mechanical devices and accessories having casters.

[0014] Embodiments disclosed herein provide a caster having a retractable guard assembly that automatically retracts when a corresponding caster wheel encounters a fixed object. The automatically retractable guard assembly allows the mobile equipment to easily move over fixed objects without requiring user action. Furthermore, the retractable guard assembly disclosed herein retracts only when it comes into contact with an object that applies a sufficiently large reaction force (to the corresponding guard of the retractable guard assembly) to satisfy a threshold condition. This mechanism allows the retractable guard assembly to push the unstable object out of the path of the corresponding caster wheel, preventing the caster wheel from getting caught on the unstable object, while simultaneously allowing the caster wheel to move over the fixed object. In addition, the retractable guard assembly disclosed herein is designed to yield to a fixed object approaching from any direction, including forward, backward, or downward (for example, when the mobile equipment is being lowered or operated to ascend or descend an overhang).

[0015] Figure 1 shows a medical device 100 including four caster assemblies 102a, 102b, 102c, and 102d (not shown). As shown, each caster assembly 102 includes a caster (e.g., caster 303 shown in Figure 3A) having a rotating caster wheel ("caster wheel") 101 and a caster lock toe hold 106. When the caster lock toe hold 106 is pressed, the caster lock toe hold 106 comes into contact with the ground, creating friction that can prevent the corresponding caster wheel 101 from rotating.

[0016] Each caster assembly 102 also includes a retractable guard assembly 104, as will be described in more detail below. In certain embodiments, each retractable guard assembly 104 is attached to the corresponding caster during the manufacturing process. As will be further described with reference to Figures 2A–2C, each retractable guard assembly 104 comprises one or more guards that are independently movable relative to each other and relative to the caster assembly 102. When deployed, the guards are configured to push aside objects such as cables, hoses, and other similar objects. In the deployed state, the guards provide a certain amount of clearance from the ground so that the medical device 100 can be moved around. However, the clearance (e.g., the distance between the bottom of the guard and the ground) is configured so that the guards are still able to contact and push aside cables, hoses, and other similar objects. If one or more of the guards come into contact with an object not intended to be pushed aside, the corresponding guards will retract, thereby increasing the clearance between the guard and the ground, and as a result, the medical device 100 will be easily moved over fixed objects (e.g., obstacles) such as door sills and elevator sills, and immovable obstacles such as floor mats. Note that in certain embodiments, any immovable obstacle may be considered a fixed object. As used herein, the term “fixed object” means any object that causes at least one of the guards to retract by applying a sufficiently large force to it.

[0017] FIG. 2A shows a side view of the caster assembly 102 of FIG. 1 including the retractable guard assembly 104 in a deployed state, in accordance with some embodiments. FIG. 2B shows a perspective view of the caster assembly 102 including the retractable guard assembly 104 in a deployed state, in accordance with some embodiments. FIG. 2C shows a perspective view of the caster assembly 102 including the retractable guard assembly 104 with the front guard 210a in a stowed state, in accordance with some embodiments. The caster assembly 102 shown in FIGS. 2A to 2C may be any one of the caster assemblies 102a, 102b, 102c, or 102d of FIG. 1. For clarity, FIGS. 2A to 2C are described together herein.

[0018] The retractable guard assembly 104 is mounted on a caster (shown as caster 303 in Figure 3A), which includes a caster wheel 101 and a caster lock toe hold 106, among other components. The retractable guard assembly 104 comprises a housing 208, a front guard 210, a rear guard 212, a collar 216, a screw 218, and other components shown in detail in Figure 3A. The housing 208 comprises two housing pieces 209a and 209b. In Figure 2A, only housing piece 209a is shown, but in Figures 2B and 2C, housing piece 209b is partially shown. Housing pieces 209a and 209b are joined together using screws 218a-218c. Housing pieces 209a and 209b are indirectly joined together via the collar 216. Housing piece 209a is joined to collar 216 using screws 218d, and housing piece 209b is joined to collar 216 using screws 218e. The front guard 210 and rear guard 212 are located at least partially inside the housing 208. Only portions of the front guard 210 and rear guard 212, which are located outside the housing 208, are visible in Figures 2A to 2C. As shown, the front guards 210a and 210b are arranged symmetrically such that there is one front guard on each side of the caster wheel 101. The rear guards 212a and 212b are also arranged symmetrically such that there is one rear guard on each side of the caster wheel 101.

[0019] As described above, in the deployed state, the front guard 210 and the rear guard 212 provide a minimal amount of clearance with the ground, allowing the medical device 100 to move around while pushing any object such as a cable out of its path. When the front guard 210 and the rear guard 212 are in the fully deployed state (shown in Figure 2B), contact between the stationary object 214 (shown in Figure 2C) and a portion of either the front guard 210 or the rear guard 212 disposed on the outside of the housing 208 causes the corresponding guard to transition to the stowed state. It should be noted that since the guards are movable independently of one another, any one of the four guards can be stowed while the other guards remain deployed. For example, as shown in Figure 2C, the front guards 210a and 210b are in the stowed state, and the rear guards 212a and 212b remain in the deployed state. In Figure 2C, the front guards 210a and 210b have a greater clearance with the ground than the rear guards 212a and 212b. In addition, the front guards 210a and 210b in the stowed state (shown in Figure 2C) have a greater clearance with the ground than the front guards 210a and 210b in the fully deployed state (shown in Figure 2B).

[0020] When the contact with the stationary object 214 is removed while the front guard 210 is in the stowed state (shown in Figure 2C), the corresponding guard automatically deploys to the fully deployed state (shown in Figure 2B) or transitions back to its original state. Although only the fully deployed state of the rear guard 212 is shown, the rear guard 212 functions similarly to the front guard 210. As will be described in more detail below with respect to Figures 3A to 3C and Figures 4A to 4B, the transition to the fully deployed state is caused by a corresponding biasing element that biases or preloads each guard toward the fully deployed state.

[0021] Figure 3A shows an exploded view of the caster assembly 102 of Figures 2A-2C according to a particular embodiment. As shown, the cover 320b is coupled to the housing piece 209b using screws 322. Screws 322a-322d are configured to be inserted in this order into the corresponding openings in the cover 320b and the corresponding threaded holes in the housing piece 209b. When screws 322a-322d are inserted into all such openings, the screws 322a-322d hold the cover 320b and the housing piece 209b together so that the front guard 210b and the rear guard 212b are at least partially positioned within the housing and are movably coupled between the cover 320b and the housing piece 209b. Cover 320a functions similarly to cover 320b. Cover 320a is coupled to the housing piece 209a using screws 321. The screws 321a to 321d are configured to be inserted in this order into the corresponding openings in the cover 320a and the corresponding threaded holes in the housing piece 209a. When the screws 321a to 321d are inserted into all such openings, the screws 321a to 321d hold the cover 320a and the housing piece 209a together so that the front guard 210a and the rear guard 212a are at least partially positioned within the housing and are movably coupled between the cover 320a and the housing piece 209a.

[0022] As shown in the figures, the front guard 210b has a lower slot 311b corresponding to the lower pin 326b of the housing piece 209b and an upper slot 313b corresponding to the upper pin 328b of the housing piece 209b. When the cover 320b is coupled to the housing piece 209b, the lower pin 326b is located in the lower slot 311b and the upper pin 328b is located in the upper slot 313b. As will be described in more detail below with respect to Figures 4A and 4B, a first contact interface between the periphery of the lower slot 311b and the corresponding lower pin 326b, and a second contact interface between the periphery of the upper slot 313b and the corresponding upper pin 328b limit the range of motion and guide the movement of the front guard 210b.

[0023] The rear guard 212b functions similarly to the front guard 210b. The rear guard 212b has a lower slot 315b corresponding to the lower pin 327b of the housing piece 209b and an upper slot 317b corresponding to the upper pin 329b of the housing piece 209b. When the cover 320b is coupled to the housing piece 209b, the lower pin 327b is located in the lower slot 315b and the upper pin 329b is located in the upper slot 317b. The front guard 210a and the rear guard 212a function similarly to the front guard 210b and the rear guard 212b. The front guard 210a has a lower slot 311a corresponding to the lower pin 326a (shown in Figure 4A) of the housing piece 209a and an upper slot 313a corresponding to the upper pin 328a of the housing piece 209a. When the cover 320a is coupled to the housing piece 209a, the lower pin 326a is located in the lower slot 311a and the upper pin 328a is located in the upper slot 313a. The rear guard 212a has a lower slot 315a corresponding to the lower pin 327a (shown in Figure 4A) of the housing piece 209a and an upper slot 317a corresponding to the upper pin 329a of the housing piece 209a. When the cover 320a is coupled to the housing piece 209a, the lower pin 327a is located in the lower slot 315a and the upper pin 329a is located in the upper slot 317a.

[0024] As shown in the figure, the lower pins 326a, 326b, 327a, and 327b are vertically spaced from the upper pins 328a, 328b, 329a, and 329b, which means that the lower pins 326a, 326b, 327a, and 327b may be located closer to the ground compared to the upper pins 328a, 328b, 329a, and 329b. As shown in the figure, the lower pins 326a, 326b, 327a, and 327b and the upper pins 328a, 328b, 329a, and 329b extend inward from the corresponding housing pieces 209a-209b and are positioned on an axis parallel to the ground surface (for example, an axis passing through all the openings of the cover and perpendicular to the outer surface of the caster wheel 101). In addition, as will be described later, the lower pins 326a, 326b, 327a, and 327b are longer than the upper pins 328a, 328b, 329a, and 329b in order to engage the corresponding covers 320a to 320b which are coupled to the corresponding housing pieces 209a to 209b. After the lower pins 326a, 326b, 327a, and 327b are inserted through the corresponding slots 311a, 311b, 315a, and 315b, the lower pins 326a, 326b, 327a, and 327b are further inserted into the corresponding openings of the covers 320a to 320b. Therefore, the front guard 210a and rear guard 212a are movably locked between the housing piece 209a and the opposing cover 320a, and the front guard 210b and rear guard 212b are similarly movably locked between the housing piece 209b and the opposing cover 320b. The front guard 210 and rear guard 212 are oriented longitudinally, substantially perpendicular to the ground surface. The movement of the guards is substantially limited to a vertical plane (e.g., a plane perpendicular to the ground surface). As will be described in more detail below with respect to Figures 4A and 4B, the range of motion of each guard is limited to the area defined by the contact between each slot and the corresponding pin.

[0025] As shown in the figure, the biasing element 330b is configured to connect to the lower pin 326b at its lower end and to the hook 334b ​​of the front guard 210b at its upper end. The lower end of each biasing element points to the end closer to the ground. The upper end of each biasing element points to the end further from the ground. The biasing element 330b biases the upper end of the front guard 210b toward the lower pin 326b. Since the lower pin 326b is fixed to the housing piece 209b, the front guard 210b is biased downward and fully extended (as shown in Figure 2B). The biasing element 332b functions similarly to the biasing element 330b. The biasing element 332b is configured to connect to the lower pin 327b at its lower end and to the hook 336b of the rear guard 212b at its upper end. The biasing elements 330a and 332a function similarly to the biasing elements 330b and 332b. The biasing element 330a is configured to be coupled to the lower pin 326a at its lower end and to the hook 334a of the front guard 210a at its upper end. The biasing element 332a is configured to be coupled to the lower pin 327a at its lower end and to the hook 336a of the rear guard 212a at its upper end.

[0026] The components held together using screws 321a to 321d and the components held together using screws 322a to 322d are configured to be joined together by screwing housing piece 209a into housing piece 209b using screws 218a to 218c. The screws 218a to 218c are configured to be inserted in this order into the corresponding openings of housing piece 209a and the corresponding threaded holes of housing piece 209b. When housing piece 209a and housing piece 209b are joined together and mounted on the corresponding caster, the collar 216 is joined to the assembled housing piece using screws 218d to 218e and the corresponding threaded caps 319d to 319e.

[0027] Figures 3B–C show assumed dimensions for a cross-section of an embodiment of a caster assembly according to a particular embodiment of the present disclosure. Figure 3C shows a cross-sectional view taken at A shown in Figure 3B. For clarity, the screws 322a–d and the biasing elements 330b and 332b are removed in the cross-sectional view shown in Figure 3C. In some embodiments, the distance 350 between the centerline and the upper pin 329b may range from approximately 10 mm (0.4 inches) to 35.6 mm (1.4 inches), for example, 23 mm (0.9 inches). In some embodiments, the horizontal distance 352 between the upper pin 329b and the left radial forming portion of the rear guard 312b may range from approximately 1.3 mm (0.05 inches) to 18 mm (0.7 inches), for example, 8.74 mm (0.344 inches). In some embodiments, the horizontal distance 354 between the upper pin 329b and the right radially formed portion of the rear guard 312b may range from approximately 6.4 mm (0.25 inches) to 20 mm (0.8 inches), for example, 13.9 mm (0.549 inches). In some embodiments, the distance 356 between the upper pin 329b and the lower pin 327b may range from approximately 30 mm (1.2 inches) to 57 mm (2.25 inches), for example, 44.96 mm (1.770 inches). In some embodiments, the vertical distance 358 between the upper pin 329b and the right radially formed portion of the rear guard 312b may range from approximately 7.6 mm (0.3 inches) to 23 mm (0.9 inches), for example, 15.1 mm (0.594 inches). In some embodiments, the vertical distance 360 ​​between the upper pin 329b and the left radially formed portion of the rear guard 312b may range from approximately 7.6 mm (0.3 inches) to 23 mm (0.9 inches), for example, 14.4 mm (0.568 inches). In some embodiments, the length 362 of the slot 315b may range from approximately 6.4 mm (0.25 inches) to 25.4 mm (1.0 inch), for example, 16.5 mm (0.650 inches). In some embodiments, the width 364 of the slot 315b may range from approximately 1.3 mm (0.05 inches) to 10 mm (0.4 inches), for example, 4.6 mm (0.180 inches).In some embodiments, the angle 366 between the center line and the line passing through the center of slot 315b and upper pin 329b may be in the range of approximately 5 to 25 degrees, for example, 10 degrees. In some embodiments, the vertical distance 368 between the left radial forming section and the right radial forming section and the bottom of the rear guard 312b may be in the range of approximately 25.4 mm (1 inch) to 102 mm (4 inches), for example, 60.12 mm (2.367 inches). In some embodiments, the wheel diameter 370 may be in the range of approximately 76 mm (3 inches) to 178 mm (7 inches), for example, 125.0 mm (4.921 inches). While some exemplary dimensions are provided above, it should be understood that other dimensions are also conceivable. For example, if the wheel diameter is smaller or larger than the dimensions shown above, those dimensions may be appropriately scaled up or down to suit wheels of different sizes. Furthermore, other angles and dimensions are also suitable for the casters described herein, and the above embodiments are not intended to be limiting, but rather exemplify conceivable caster embodiments.

[0028] Figure 4A shows an internal side view of the front guard 210a, the rear guard 212a, and the housing piece 209a. In Figure 4A, the front guard 210a and the rear guard 212a are in a fully deployed state. In the fully deployed state, the lower pins 326a and 327a are located at the upper ends of the lower slots 311a and 315a, respectively. Furthermore, in the fully deployed state, the upper pins 328a and 329a (which are not visible in Figure 4A as they are located on the back side of the corresponding biasing elements 330a and 332a) are located at the upper ends of the upper slots 313a and 317a, respectively. The upper end of each slot refers to the end furthest from the ground. The lower end of each slot refers to the end closer to the ground. As shown in the figure, the main body 440a of the front guard 210a has a first end 442a located inside the periphery of the housing piece 209a and a second end 444a located outside the periphery of the housing piece 209a. The periphery of the housing piece 209a refers to the area inside the housing piece 209a when viewed from the side. When fully deployed, the front guard 210a has a minimum first clearance from the ground. The clearance from the ground refers to the distance from the ground to the second end 444a, and this distance is measured perpendicular to the ground surface.

[0029] The main body 440a has a side wall 446a that extends at least partially around the periphery of the main body 440a. The side wall 446a refers to a raised portion of the main body 440a that defines an inner cavity 448a between opposing portions of the side wall 446a. The main body 440a has a tip edge 454a formed along a portion of the side wall 446a that is located outside the periphery of the housing piece 209a. The tip edge refers to the outward-facing portion of each guard that is configured to make initial contact with an object as the medical device 100 moves back and forth on the caster assembly 102. The tip edge 454a is perpendicular to the ground surface and provides a large surface area for an object to contact the front guard 210a from the front. In certain other embodiments, the tip edge 454a is not perpendicular to the ground surface. In certain embodiments, the tip edge 454a has a surface profile (e.g., horizontal or vertical ridges, a grid pattern, or any preferred surface texture) to increase friction between the tip edge 454a and the contacting object and prevent slippage.

[0030] The main body 440a has an outer surface 450a on one side (for example, the side closer to the indicated housing piece 209a) that surrounds the inner cavity 448a. The outer surface 450a extends between opposing portions of the side wall 446a. The lower slot 311a and the upper slot 313a are defined on the outer surface 450a. A hook 334a is located at the first end 442a of the main body 440a. The upper end of the biasing element 330a fits around the hook 334a, connecting the biasing element 330a to the front guard 210a. At the first end 442a of the main body 440a, a notch 452a is formed through the side wall 446a. The notch 452a provides an opening for the biasing element 330b, which extends through the side wall 446a to connect to the hook 334a. As shown in the figure, the biasing element 330a fits into the inner cavity 448a. The lower end of the biasing element 330a fits around the lower pin 326a, and the biasing element 330a is coupled to the housing piece 209a.

[0031] The rear guard 212a, front guard 210b, and rear guard 212b are each constructed and configured similarly to the front guard 210a. For example, referring to the rear guard 212a (shown in Figure 4A), the body 441a of the rear guard 212a has a first end 443a located inside the periphery of the housing piece 209a and a second end 445a located outside the periphery of the housing piece 209a. The body 441a has a side wall 447a that extends at least partially around the periphery of the body 441a. The body 441a has a tip edge 455a formed along a portion of the side wall 447a located outside the periphery of the housing piece 209a. The tip edge 455a is perpendicular to the ground surface and provides a large surface area for an object to contact the rear guard 212a from the rear. In certain other embodiments, the tip edge 455a is not perpendicular to the ground surface. In certain embodiments, the tip edge 455a has a surface profile (e.g., horizontal or vertical ridges, a grid pattern, or any preferred surface texture) to increase friction between the tip edge 455a and the contacting object and prevent slippage. As shown behind the biasing element 332a, the body 441a has an outer surface 451a on one side (e.g., the side closer to the housing piece 209a shown) that surrounds the inner cavity 449a. The outer surface 451a extends between opposing portions of the side wall 447a. The lower slot 315a and the upper slot 317a are defined on the outer surface 451a. A hook 336a is located on the first end 443a of the body 441a. The upper end of the biasing element 332a fits around the hook 336a, connecting the biasing element 332a to the rear guard 212a. A notch 453a is formed at the first end 443a of the main body 441a through the side wall 447a. The notch 453a provides an opening for the biasing element 332b, extending through the side wall 447a for the biasing element 332b to connect to the hook 336a. As shown in the figure, the biasing element 332a fits into the inner cavity 449a. The lower end of the biasing element 332a fits around the lower pin 327a, and the biasing element 332a connects to the housing piece 209a.

[0032] Figure 4B shows an internal side view of the front guard 210a, the rear guard 212a, and the housing piece 209a. In Figure 4B, the rear guard 212a remains fully extended, while the front guard 210a has transitioned to a retracted state. As shown, the front guard 210a is in a fully retracted state. Note that in certain embodiments, any state other than fully extended may be considered retracted or partially retracted. Such a state may also be considered partially extended. As shown, contact between a portion of the front guard 210a (e.g., the tip edge 454a or the second end 444a) located outside the housing 209a and the fixed object 214 causes the front guard 210a to transition to a retracted state. In the fully retracted state, the lower pin 326a is located at the lower end of the lower slot 311a, and the upper pin 328a (located behind the biasing element 330a in Figure 4B) is located at the lower end of the upper slot 313a. In the retracted state, the front guard 210a is moved upward against the downward biasing force of the biasing element 330a. In the retracted state, the front guard 210a has a second clearance from the ground that is greater than the first clearance shown in Figure 4A. In Figure 4B, which shows the front guard in the fully retracted state, the second clearance is at its maximum. In the retracted state, the biasing element 330a is extended compared to the same biasing element in the deployed state. As shown in Figure 4B, the biasing element 330a is also extended compared to the biasing element 332a. The retraction of the front guard 210a is described in further detail below with reference to Figures 5A to 5D.

[0033] Figures 5A to 5D show the motion of the front guard 210a relative to the lower pin 326a and upper pin 328a during contact with the fixed object 214 and during subsequent motion over the fixed object. For clarity, all other components of the caster assembly 102 are omitted from Figures 5A to 5D, except for the caster wheel 101, which is shown by dashed lines. As shown in Figure 5A, the caster wheel 101 is positioned to the left of the fixed object 214, and the front guard 210 is in a fully extended state. In the fully extended state, the lower pin 326a is positioned at the upper end of the lower slot 311a, and the upper pin 328a is positioned at the upper end of the upper slot 313a. The front guard 210a is centered relative to the upper pin 328a due to the fact that the front guard 210a is biased downward in combination with the shape of the upper slot 313a, which converges at the upper end.

[0034] As shown in Figure 5B, the caster wheel 101 is approaching the stationary object 214, and the front guard 210a is transitioning to a first retracted state. Note that in the position shown in Figure 5B, the caster wheel 101 is still spaced apart from the stationary object 214. As shown, the leading edge 454a of the front guard 210a is in contact with the left side 214a of the stationary object 214. The movement of the front guard 210a (e.g., retraction) is guided by a first part by contact between the periphery of the lower slot 311a and the corresponding lower pin 326a, and a second part by contact between the periphery of the upper slot 313a and the corresponding upper pin 328a. The lower slot 311a has a linear shape configured to limit the translational motion of the front guard 210a to only two directions. In other words, the width of the lower slot 311a is approximately the same as the diameter of the lower pin 326a, so that the lower pin 326a can move in only two directions (e.g., up and down) within the lower slot 311a. In contrast to the lower slot 311a, the upper slot 313a has a nonlinear shape configured to allow translational motion of the forward guard 210a in any direction. In other words, the width and length of the upper slot 313a are both greater than the diameter of the upper pin 328a, so that the upper pin 328a can move in any direction (e.g., up, down, left, and right) within the upper slot 313a. As shown in the figure, the upper slot 313a is triangular. Alternatively, the upper slot 313a may be square, rectangular, circular, or any other preferred nonlinear shape.

[0035] As the upper slot 313a moves in any direction relative to the upper pin 328a, the lower slot 311a can not only translate along its longitudinal axis but also rotate about the longitudinal axis of the lower pin 326a. Therefore, as the front guard 210a contacts the left side 214a of the fixed object 214 with its tip edge 454a, a lateral force acts on the front guard 210a, causing the front guard 210a and the lower slot 311a to rotate clockwise about the longitudinal axis of the lower pin 326a. The rotation of the front guard 210a causes the left side of the side wall 446a (corresponding to the periphery of slot 313a) to contact the upper pin 328a and move in translation. As shown in the figure, the shape of the upper slot 313a (widening downwards) and the extra angle of the side wall 446a cause the front guard 210a to move upward, bringing the lower slot 311a into contact with the lower pin 326a and translating it.

[0036] As shown in Figure 5C, the caster wheel 101 moves and makes contact with the stationary object 214, and the front guard 210a moves to a second retracted state which has a larger clearance from the ground compared to the first retracted state shown in Figure 5B. In Figure 5C, the caster wheel 101 is in contact with the edge connecting the side surface 214a and the top surface 214b of the stationary object 214. Comparing Figures 5B and 5C, by continuously applying a lateral force to the front guard 210a, the front guard 210a and the lower slot 311a continue to rotate clockwise around the longitudinal axis of the lower pin 326a, thereby causing the left side of the side wall 446a to continue to move translationally in contact with the upper pin 328a, and the lower slot 311a to continue to move translationally in contact with the lower pin 326a, causing the front guard 210a to continue to move upward. As shown in Figure 5C, the front guard 210a is positioned entirely within the periphery of the caster wheel 101. Therefore, the front guard 210a is retracted to its maximum extent for the illustrated movement of the caster wheel 101 beyond the fixed object 214.

[0037] As shown in Figure 5D, the caster wheel 101 moves onto the upper surface 214b of the stationary object 214, and the front guard 210a moves into a fully extended position. Although not shown, after the caster wheel 101 first moves onto the upper surface 214b of the stationary object 214, the second end 444a of the front guard 210a moves and makes contact with the upper surface 214b. At this point, the lateral force acting on the front guard 210a is removed. Instead, a vertical force acts on the second end 444a, keeping the front guard 210a in a retracted position. The continued movement of the caster wheel 101 along the upper surface 214b creates a larger clearance between the second end 444a of the front guard 210a and the upper surface 214b of the stationary object 214, allowing the front guard 210a to move into the fully extended position shown in Figure 5D. Although not shown, if the caster wheel 101 continues to move in the illustrated direction, the rear guard 212b may come into contact with the right side of the fixed object 214 as the caster wheel 101 moves away from the fixed object 214 and returns to the ground surface. In certain embodiments, the rear end edge of the rear guard 212a, or the second end 445a of the rear guard 212a, opposite the front edge 455a (shown in Figures 4A-4B), may come into contact with the right side of the fixed object 214, causing the rear guard 212a to move into a third retracted state.

[0038] Although not shown in the operation, the structure and function of the rear guard 212a (shown in Figures 4A to 4B) are the inverse of the structure and function of the front guard 210a, and as a result, the rear guard 212a can yield to a fixed object approaching from the opposite direction to that shown in Figures 5A to 5D. In such an embodiment, as the rear guard 212a makes contact with the right side of the fixed object 214 at its tip edge 455a, a lateral force acts on the rear guard 212a, causing the rear guard 212a and the lower slot 315a to rotate counterclockwise around the longitudinal axis of the lower pin 327a. The rotation of the rear guard 212a causes the right side of the side wall 447a (corresponding to the periphery of the slot 317a) to come into contact with the upper pin 329a and move in translation. The shape of the upper slot 317a (which widens downwards) and the extra angle of the side wall 447a cause the rear guard 212a to move upwards, bringing the lower slot 315a into contact with the lower pin 327a and causing it to move translationally.

[0039] Accordingly, the specific embodiments described herein provide retractable guard assemblies that can be used with the caster wheels of equipment. The retractable guard assemblies can be deployed to push aside objects such as cables and hoses when moving the equipment around. The retractable guard assemblies can also be retracted when moving the equipment over fixed obstacles such as door sills and elevator sills, or non-fixed but immovable obstacles such as floor mats.

[0040] The foregoing description is provided so that any person skilled in the art can practice the various embodiments described herein. Various modifications to these embodiments will be readily apparent to a person skilled in the art, and the general principles defined herein may be applied to other embodiments. Accordingly, the claims are not intended to be limited to the embodiments shown herein, but rather the full scope consistent with the language of the claims should be recognized. Furthermore, this disclosure includes the following inventions. The first aspect is, A retractable guard assembly that is coupled to the caster of a movable device, Housing and One or more guards, at least partially located within the housing, and coupled to the housing so as to be independently movable, A corresponding biasing element coupled to the one or more guards and the housing for biasing the one or more guards toward a fully deployed state, When one or more guards are in the fully extended state, contact between the fixed object and a portion of one or more guards located outside the housing causes one or more guards to transition to the retracted state. When the contact is removed while one or more guards are in the retracted state, the corresponding one or more biasing elements move the one or more guards to the fully deployed state. In the fully extended state, the one or more guards have a first clearance from the ground. In the retracted state, the one or more guards have a second clearance between themselves and the ground. The second clearance is greater than the first clearance, and comprises one or more corresponding biasing elements. This is a retractable guard assembly equipped with [a specific feature / feature]. The second aspect is, Each of the one or more guards mentioned above is A first slot corresponding to the first pin of the housing, A retractable guard assembly in a first embodiment, comprising: a second slot corresponding to a second pin of the housing, wherein the range of motion of one or more guards is limited to a region defined by a first contact between the first slot and the corresponding first pin, and a second contact between the second slot and the corresponding second pin. The third aspect is, Each of the one or more guards mentioned above is The body further comprises a first end disposed inside the housing and a second end disposed outside the housing, the body being, The side wall that defines the inner cavity, An outer surface that surrounds the inner cavity on one side, wherein the first slot and the second slot are defined by the outer surface, A retractable guard assembly in a second embodiment, comprising: a hook at the first end of the main body, configured to connect one or more corresponding biasing elements to one or more guards. The fourth aspect is, The side wall is a retractable guard assembly in a third embodiment, wherein the side wall has a notch at the first end of the main body, and one or more corresponding biasing elements fit into the inner cavity, extend through the notch, and connect to the hook. The fifth aspect is, A retractable guard assembly in a second embodiment, wherein the first slot is configured to allow translational motion of the one or more guards in any direction, and the second slot is configured to restrict the translational motion of the one or more guards to only two directions. The sixth aspect is, The transition of one or more guards to the retracted state is guided by the first contact between the periphery of the first slot and the corresponding first pin, and by the second contact between the periphery of the second slot and the corresponding second pin. During the transition to the stored state, the second slot rotates about the longitudinal axis of the second pin and translates along the first axis in the first direction. During the transition to the retracted state, the first slot is a retractable guard assembly in a second embodiment, which translates in a second direction including a first component along the first axis and a second component along a second axis perpendicular to the first axis. The seventh aspect is, When one or more of the guards are in the fully deployed state, the first pin is positioned at the first upper end of the corresponding first slot, and the second pin is positioned at the second upper end of the corresponding second slot. In a second embodiment, a retractable guard assembly is provided, wherein when one or more guards are fully retracted, the first pin is located at the first lower end of the corresponding first slot, and the second pin is located at the second lower end of the corresponding second slot. The eighth aspect is, In the fully extended state, the one or more guards are configured to push objects away while the movable device is moving. In the retractable guard assembly according to the first embodiment, the second clearance provides sufficient distance from the ground so that the movable device can move over a fixed object when in the retracted state. The ninth aspect is, The one or more guards are a retractable guard assembly in a first embodiment, comprising two pairs of guards symmetrically arranged on opposing sides of the caster's wheel. The tenth aspect is, A caster assembly for a movable device, Casters equipped with caster wheels, A retractable guard assembly coupled to the caster, wherein the retractable guard assembly is Housing and One or more guards, at least partially located within the housing, and coupled to the housing so as to be independently movable, A corresponding biasing element coupled to the one or more guards and the housing for biasing the one or more guards toward a fully deployed state, When one or more guards are in the fully extended state, contact between the fixed object and a portion of one or more guards located outside the housing causes one or more guards to transition to the retracted state. When the contact is removed while one or more guards are in the retracted state, the corresponding one or more biasing elements move the one or more guards to the fully deployed state. In the fully extended state, the one or more guards have a first clearance from the ground. In the retracted state, the one or more guards have a second clearance between themselves and the ground. A retractable guard assembly comprising one or more corresponding biasing elements, wherein the second clearance is greater than the first clearance, This is a caster assembly equipped with [features / equipment]. The eleventh aspect is, Each of the one or more guards mentioned above is A first slot corresponding to the first pin of the housing, A caster assembly in a tenth embodiment, comprising: a second slot corresponding to a second pin of the housing, wherein the range of motion of one or more guards is limited to a region defined by a first contact between the first slot and the corresponding first pin, and a second contact between the second slot and the corresponding second pin. The twelfth aspect is, Each of the one or more guards mentioned above is The device further comprises a body having a first end disposed inside the housing and a second end disposed outside the housing, and a body having a first end disposed inside the housing and a second end disposed outside the housing, the body being The side wall that defines the inner cavity, An outer surface that surrounds the inner cavity on one side, wherein the first slot and the second slot are defined by the outer surface, A caster assembly in an eleventh embodiment, comprising: a hook at the first end of the body configured to connect one or more corresponding biasing elements to one or more guards. The 13th aspect is, A caster assembly in an eleventh embodiment, wherein the first slot is configured to allow translational motion of the one or more guards in any direction, and the second slot is configured to restrict the translational motion of the one or more guards to only two directions. The 14th aspect is, The transition of one or more guards to the retracted state is guided by the first contact between the periphery of the first slot and the corresponding first pin, and by the second contact between the periphery of the second slot and the corresponding second pin. During the transition to the stored state, the second slot rotates about the longitudinal axis of the second pin and translates along the first axis in the first direction. During the transition to the retracted state, the first slot is a caster assembly in an eleventh embodiment, which translates in a second direction including a first component along the first axis and a second component along a second axis perpendicular to the first axis. The 15th aspect is, In the fully extended state, the one or more guards are configured to push objects away while the movable device is moving. A caster assembly in a tenth embodiment, wherein the second clearance provides sufficient distance from the ground so that the movable device can move over a fixed object in the retracted state.

Claims

1. A retractable guard assembly that is coupled to the caster of a movable device, Housing and One or more guards, at least partially located within the housing, and coupled to the housing so as to be independently movable, A corresponding biasing element coupled to the one or more guards and the housing for biasing the one or more guards toward a fully deployed state, When one or more guards are in the fully extended state, contact between the fixed object and a portion of one or more guards located outside the housing causes one or more guards to transition to the retracted state. When the contact is removed while one or more of the guards are in the retracted state, the corresponding one or more biasing elements move the one or more of the guards to the fully deployed state. In the fully extended state, the one or more guards have a first clearance from the ground. In the retracted state, the one or more guards have a second clearance between themselves and the ground. The second clearance is greater than the first clearance, and comprises one or more corresponding biasing elements. Equipped with, Each of the one or more guards mentioned above is A first slot corresponding to the first pin of the housing, A second slot corresponding to a second pin of the housing, wherein the range of motion of one or more guards is limited to a region defined by a first contact between the first slot and the corresponding first pin, and a second contact between the second slot and the corresponding second pin, Each of the one or more guards mentioned above is The housing further comprises a main body having a first end disposed inside the housing and a second end disposed outside the housing, the main body being The side wall that defines the inner cavity, An outer surface that surrounds the inner cavity on one side, wherein the first slot and the second slot are defined by the outer surface, A retractable guard assembly comprising: a hook at the first end of the main body, configured to connect one or more corresponding biasing elements to one or more guards.

2. The retractable guard assembly according to claim 1, wherein the side wall has a notch at the first end of the main body, and one or more corresponding biasing elements fit into the inner cavity, extend through the notch and connect to the hook.

3. The retractable guard assembly according to claim 1, wherein the first slot is configured to allow translational motion of the one or more guards in any direction, and the second slot is configured to restrict the translational motion of the one or more guards to only two directions.

4. The transition of one or more guards to the retracted state is guided by the first contact between the periphery of the first slot and the corresponding first pin, and by the second contact between the periphery of the second slot and the corresponding second pin. During the transition to the stored state, the second slot rotates about the longitudinal axis of the second pin and translates along the first axis in the first direction. During the transition to the retracted state, the first slot translates in a second direction, comprising a first component along the first axis and a second component along a second axis perpendicular to the first axis, according to claim 1.

5. When one or more of the guards are in the fully deployed state, the first pin is positioned at the first upper end of the corresponding first slot, and the second pin is positioned at the second upper end of the corresponding second slot. The retractable guard assembly according to claim 1, wherein when one or more guards are fully retracted, the first pin is located at the first lower end of the corresponding first slot and the second pin is located at the second lower end of the corresponding second slot.

6. In the fully deployed state, one or more guards are configured to push objects away while the movable device is moving. The retractable guard assembly according to claim 1, wherein the second clearance provides sufficient distance from the ground so that the movable device can move over a fixed object in the retracted state.

7. The retractable guard assembly according to claim 1, wherein the one or more guards comprises two pairs of guards symmetrically arranged on opposing sides of the caster's wheel.

8. A caster assembly for a movable device, Casters equipped with caster wheels, A retractable guard assembly coupled to the caster, wherein the retractable guard assembly is Housing and One or more guards, at least partially located within the housing, and coupled to the housing so as to be independently movable, A corresponding biasing element coupled to the one or more guards and the housing for biasing the one or more guards toward a fully deployed state, When one or more guards are in the fully extended state, contact between the fixed object and a portion of one or more guards located outside the housing causes one or more guards to transition to the retracted state. When the contact is removed while one or more of the guards are in the retracted state, the corresponding one or more biasing elements move the one or more of the guards to the fully deployed state. In the fully extended state, the one or more guards have a first clearance from the ground. In the retracted state, the one or more guards have a second clearance between themselves and the ground. A retractable guard assembly comprising one or more corresponding biasing elements, wherein the second clearance is greater than the first clearance, Equipped with, Each of the one or more guards mentioned above is A first slot corresponding to the first pin of the housing, The housing comprises a second slot corresponding to a second pin, wherein the range of motion of one or more guards is limited to a region defined by a first contact between the first slot and the corresponding first pin, and a second contact between the second slot and the corresponding second pin. Each of the one or more guards mentioned above is The device further comprises a body having a first end disposed inside the housing and a second end disposed outside the housing, and a body having a first end disposed inside the housing and a second end disposed outside the housing, the body being The side wall that defines the inner cavity, An outer surface that surrounds the inner cavity on one side, wherein the first slot and the second slot are defined by the outer surface, A caster assembly comprising: a hook at the first end of the main body, configured to connect one or more corresponding biasing elements to one or more guards.

9. The caster assembly according to claim 8, wherein the first slot is configured to allow translational motion of the one or more guards in any direction, and the second slot is configured to limit the translational motion of the one or more guards to only two directions.

10. The transition of one or more guards to the retracted state is guided by the first contact between the periphery of the first slot and the corresponding first pin, and by the second contact between the periphery of the second slot and the corresponding second pin. During the transition to the stored state, the second slot rotates about the longitudinal axis of the second pin and translates along the first axis in the first direction. During the transition to the retracted state, the first slot translates in a second direction, comprising a first component along the first axis and a second component along a second axis perpendicular to the first axis, according to claim 8.

11. In the fully deployed state, one or more guards are configured to push objects away while the movable device is moving. The caster assembly according to claim 8, wherein the second clearance provides a sufficient distance from the ground so that the movable device can move over a fixed object in the stored state.

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