Retractable guard assemblies

Particular embodiments disclosed herein provide a retractable guard assembly coupled to a caster of a mobile equipment, comprising a housing and one or more guards at least partially disposed in the housing. The one or more guards are independently movably coupled to the housing. The retractable guard assembly further comprises corresponding one or more biasing elements coupled to the one or more guards and to the housing for biasing the one or more guards towards a fully deployed state. When the one or more guards are in the fully deployed state, contact between a fixed object and a portion of the one or more guards disposed outside the housing causes the one or more guards to transition into a retracted state, and when the contact is removed, the corresponding one or more biasing elements cause the one or more guards to transition into the fully deployed state.

BACKGROUND

Field

The present disclosure relates generally to retractable guard assemblies for use in connection with casters of mobile equipment, such as medical or non-medical equipment.

Description of the Related Art

Many types of equipment, particularly medical equipment, have rotating caster wheels such that they can be mobile and moved around. For example, this mobility allows medical staff to move medical equipment around in operating rooms, from one operating room to another, from one floor to another (e.g., using elevators), etc. However, in certain cases, an equipment (e.g., medical equipment) rolling on caster wheels may bind when the equipment is rolled onto electrical cables, fluid hoses, and other similar objects. This is a nuisance to the equipment operator and reduces the equipment's mobility. Further, it can cause the equipment to tip over, damage the electrical cables, pinch hoses shut, and pose other similar issues.

In certain cases, certain existing cable guards are used in conjunction with casters for purposes of pushing cables and hoses aside, such as to prevent the equipment from rolling onto the cables and hoses and causing the issues discussed above. However, the existing cable guards pose certain additional and undesired issues. For example, some of the existing cable guards have to be removed and stored when the equipment is moved over fixed obstacles such as doorsills and elevator sills or non-fixed but difficult-to-move obstacles such as floor mats. Forcing an equipment operator to remove and store cable guards every time the equipment has to be moved over such objects, however, is extremely burdensome for the operator.

Some of the other existing cable guards are in a fixed position and, therefore, cannot even be removed when the equipment is about to move over fixed obstacles. As such, the fixed cable guards bind on such obstacles and can cause the equipment to tip over.

BRIEF SUMMARY

The present disclosure relates generally to retractable guard assemblies for use in connection with casters of mobile equipment, such as medical or non-medical equipment.

Particular embodiments disclosed herein provide a retractable guard assembly coupled to a caster of a mobile equipment, comprising a housing and one or more guards at least partially disposed in the housing. The one or more guards are independently movably coupled to the housing. The retractable guard assembly further comprises corresponding one or more biasing elements coupled to the one or more guards and to the housing for biasing the one or more guards towards a fully deployed state. When the one or more guards are in the fully deployed state, contact between a fixed object and a portion of the one or more guards disposed outside the housing causes the one or more guards to transition into a retracted state. When the one or more guards are in the retracted state and when the contact is removed, the corresponding one or more biasing elements cause the one or more guards to transition into the fully deployed state. In the fully deployed state, the one or more guards have a first clearance with the ground. In the retracted state, the one or more guards have a second clearance with the ground, and the second clearance is larger than the first clearance.

Particular embodiments disclosed herein provide a caster assembly of a mobile equipment, comprising a caster comprising 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 disposed in the housing. The one or more guards are independently movably coupled to the housing. The retractable guard assembly further comprises corresponding one or more biasing elements coupled to the one or more guards and to the housing for biasing the one or more guards towards a fully deployed state. When the one or more guards are in the fully deployed state, contact between a fixed object and a portion of the one or more guards disposed outside the housing causes the one or more guards to transition into a retracted state. When the one or more guards are in the retracted state and when the contact is removed, the corresponding one or more biasing elements cause the one or more guards to transition into the fully deployed state. In the fully deployed state, the one or more guards have a first clearance with the ground. In the retracted state, the one or more guards have a second clearance with the ground, and the second clearance is larger than the first clearance.

DETAILED DESCRIPTION

Particular embodiments of the present disclosure provide retractable guard assemblies that may be used in connection with casters of mobile equipment. While the embodiments below describe retractable guard assemblies that are mounted on casters and used in connection with a medical equipment, such as an ophthalmic surgical console, those of ordinary skill in the art appreciate that the retractable guard assemblies described herein may be used in conjunction with a variety of medical and non-medical equipment. Examples of such medical equipment include surgical and non-surgical consoles, diagnostic equipment, hospital beds, hospital carts, stretchers, IV (intravenous) poles and other mobile medical equipment. Examples of non-medical equipment include any mobile electrical and/or mechanical devices and accessories with casters.

Embodiments disclosed herein provide a caster with a retractable guard assembly which self-retracts when the respective caster wheel encounters fixed objects. Self-retracting guard assemblies allow mobile equipment to be easily moved over fixed objects without requiring action by the user. Furthermore, the retractable guard assemblies disclosed herein retract only when contacting objects that exert counter force (against the respective guards of the retractable guard assemblies) that is large enough to satisfy a threshold condition. This mechanism allows a retractable guard assembly to push loose objects out of the path of a corresponding caster wheel to prevent the caster wheel from binding on loose objects while at the same time allowing the caster wheel to move over fixed objects. In addition, the retractable guard assemblies disclosed herein are designed to yield to fixed objects approaching from any direction including from the front, rear, or below (e.g., when mobile equipment is set down or maneuvered up or down a ledge).

FIG.1illustrates a medical equipment100including four caster assemblies102a,102b,102c, and102d(not shown). As shown, each caster assembly102includes a caster (e.g., caster303, shown inFIG.3A) with a rotating caster wheel (“caster wheel”)101and a caster lock toehold106. Pressing caster lock toehold106causes it to make contact with the ground and, therefore, create friction that may prevent a corresponding caster wheel101from rotating.

Each caster assembly102also includes a retractable guard assembly104, as described in more detail below. In certain embodiments, each retractable guard assembly104is mounted on a corresponding caster during the manufacturing process. As further described in relation toFIGS.2A-2C, each retractable guard assembly104comprises one or more guards which are independently movable with respect to each other and with respect to caster assembly102. When deployed, the guards are configured to push objects such as cables, hoses, and other similar objects aside. In the deployed state, the guards provide a certain amount of clearance with the ground in order to allow medical equipment100to be moved around. The clearance (e.g., distance between the bottom of the guards and the ground), however, is configured such that the guards are still able to make contact with cables, hoses, and other similar objects and push them aside. When one or more of the guards contact an object which is not intended to be pushed aside, the corresponding guards are retracted, thereby creating a larger clearance with the ground, such that medical equipment100can be easily moved over fixed objects (e.g., obstacles), such as doorsills and elevator sills, and other difficult-to-move obstacles such as floor mats. Note that, in certain embodiments, any difficult-to-move obstacles may be considered as fixed objects. As used herein, the term “fixed object” refers to any object that exerts a large enough force on at least one of the guards, thereby, causing the guard to retract.

FIG.2Aillustrates a side view of a caster assembly102ofFIG.1including a retractable guard assembly104in a deployed state, according to some embodiments.FIG.2Billustrates a perspective view of caster assembly102including retractable guard assembly104in a deployed state, according to some embodiments.FIG.2Cillustrates a perspective view of caster assembly102including retractable guard assembly104with front guards210ain a retracted state, according to some embodiments. Caster assembly102, shown inFIGS.2A-2Cmay be any one of caster assemblies102a,102b,102c, or102dofFIG.1.FIGS.2A-2Care described together herein for clarity.

Retractable guard assembly104is mounted on a caster (shown as caster303inFIG.3A) that includes a caster wheel101and a caster lock toehold106, among other components. Retractable guard assembly104comprises a housing208, front guards210, rear guards212, a collar216, screws218, as well as other components shown in more detail inFIG.3A. Housing208comprises two housing pieces209aand209b. InFIG.2A, only housing piece209ais shown but housing piece209bis partly shown inFIGS.2B and2C. Housing pieces209aand209bare coupled together using screws218a-218c. Housing pieces209aand209bare indirectly coupled together through collar216. Housing piece209ais coupled to collar216using screw218d, and housing piece209bis coupled to collar216using screw218e. Front guards210and rear guards212are at least partially disposed in housing208. Only portions of front guards210and rear guards212which are disposed outside housing208are visible inFIGS.2A-2C. As shown, front guards210aand210bare positioned symmetrically such that there is a front guard on each side of caster wheel101. Rear guards212aand212bare also positioned symmetrically such that there is a rear guard on each side of caster wheel101.

As described above, in a deployed state, front guards210and rear guards212provide a minimal amount of clearance with the ground to allow medical equipment100to be moved around while also pushing any objects such as cables, out of the way. When front guards210and rear guards212are in a fully deployed state (shown inFIG.2B), contact between a fixed object214(shown inFIG.2C) and a portion of any one of front guards210or rear guards212disposed outside housing208causes the corresponding guard to transition into a retracted state. Note that because the guards are independently movable with respect to each other, any one of the four guards is able to retract while the other guards stay deployed. For example, as shown inFIG.2C, front guards210aand210bare in the retracted state, whereas rear guards212aand212bremain in the deployed state. InFIG.2C, front guards210aand210bhave a greater clearance with the ground than rear guards212aand212b. In addition, front guards210aand210bin the retracted state (shown inFIG.2C) have a greater clearance with the ground than front guards210aand210bin the fully deployed state (shown inFIG.2B).

When front guards210are in the retracted state (shown inFIG.2C) and when the contact with fixed object214is removed, the corresponding guards self-deploy or transition back into the fully deployed state (shown inFIG.2B). Although rear guards212are only shown in the fully deployed state, rear guards212function similar to front guards210. The transition to the fully deployed state is caused by corresponding biasing elements which bias, or pre-load, each of the guards towards the fully deployed state as described in more detail below with respect toFIGS.3A-Cand4A-4B.

FIG.3Aillustrates an exploded view of the caster assembly102ofFIGS.2A-2C, according to certain embodiments. As shown, a cover320bis coupled to housing piece209busing screws322. Screws322a-322dare configured to be inserted into corresponding openings of cover320band corresponding threaded holes of housing piece209b, in that order. When screws322a-322dare inserted into all such openings, screws322a-322dhold cover320band housing piece209btogether such that front guard210band rear guard212bare at least partially disposed in the housing and movably coupled between cover320band housing piece209b. Cover320afunctions similar to cover320b. Cover320ais coupled to housing piece209ausing screws321. Screws321a-321dare configured to be inserted into corresponding openings of cover320aand corresponding threaded holes of housing piece209a, in that order. When screws321a-321dare inserted into all such openings, screws321a-321dhold cover320aand housing piece209atogether such that front guard210aand rear guard212aare at least partially disposed in the housing and movably coupled between cover320aand housing piece209a.

As shown, front guard210bhas a lower slot311bcorresponding to a lower pin326bof housing piece209band an upper slot313bcorresponding to an upper pin328bof housing piece209b. When cover320bis coupled to housing piece209b, lower pin326bis disposed in lower slot311band upper pin328bis disposed in upper slot313b. A first contact interface between a perimeter of lower slot311band corresponding lower pin326band a second contact interface between a perimeter of upper slot313band corresponding upper pin328blimit a range of motion and guide the movement of front guard210bas described in more detail below with respect toFIGS.4A and4B.

Rear guard212bfunctions similar to front guard210b. Rear guard212bhas a lower slot315bcorresponding to a lower pin327bof housing piece209band an upper slot317bcorresponding to an upper pin329bof housing piece209b. When cover320bis coupled to housing piece209b, lower pin327bis disposed in lower slot315band upper pin329bis disposed in upper slot317b. Front guard210aand rear guard212afunction similar to front guard210band rear guard212b. Front guard210ahas a lower slot311acorresponding to a lower pin326a(shown inFIG.4A) of housing piece209aand an upper slot313acorresponding to an upper pin328aof housing piece209a. When cover320ais coupled to housing piece209a, lower pin326ais disposed in lower slot311aand upper pin328ais disposed in upper slot313a. Rear guard212ahas a lower slot315acorresponding to a lower pin327a(shown inFIG.4A) of housing piece209aand an upper slot317acorresponding to an upper pin329aof housing piece209a. When cover320ais coupled to housing piece209a, lower pin327ais disposed in lower slot315aand upper pin329ais disposed in upper slot317a.

As shown, lower pins326a,326b,327aand327bare spaced vertically from upper pins328a,328b,329aand329b, meaning that lower pins326a,326b,327aand327bmay be located closer to the ground compared to upper pins328a,328b,329aand329b. As shown, lower pins326a,326b,327aand327band upper pins328a,328b,329aand329bextend inwardly from respective housing pieces209a-209band are disposed on axes which are parallel to the ground surface (e.g., an axis that passes through all the openings in the cover and is perpendicular to the outer surface of caster wheel101). In addition, lower pins326a,326b,327aand327bare longer than upper pins328a,328b,329aand329bin order to engage respective covers320a-320bcoupled to corresponding housing pieces209a-209bas described below. After lower pins326a,326b,327aand327bare inserted through corresponding slots311a,311b,315aand315b, lower pins326a,326b,327aand327bare further inserted into corresponding openings of covers320a-320b. Front guard210aand rear guard212aare thereby movably locked between housing piece209aand opposing cover320a, and front guard210band rear guard212bare similarly movably locked between housing piece209band opposing cover320b. Front guards210and rear guards212are lengthwise oriented substantially perpendicular to the ground surface. Movement of the guards is substantially limited within a vertical plane (e.g., a plane perpendicular to the ground surface). A range of motion of each guard is limited to an area defined by contact between each slot and corresponding pin as described in more detail below with respect toFIGS.4A and4B.

As shown, biasing element330bis configured to be coupled at its lower end to lower pin326band at its upper end to hook334bof front guard210b. The lower end of each biasing element refers to the end that is closer to the ground. The upper end of each biasing element refers to the end that is farther from the ground. Biasing element330bbiases an upper end of front guard210bin the direction of lower pin326b. Because lower pin326bis fixed to housing piece209b, front guard210bis biased downward into a fully deployed state (shown inFIG.2B). Biasing element332bfunctions similar to biasing element330b. Biasing element332bis configured to be coupled at its lower end to lower pin327band at its upper end to hook336bof rear guard212b. Biasing elements330aand332afunction similar to biasing elements330band332b. Biasing element330ais configured to be coupled at its lower end to lower pin326aand at its upper end to hook334aof front guard210a. Biasing element332ais configured to be coupled at its lower end to lower pin327aand at its upper end to hook336aof rear guard212a.

The components that are held together using screws321a-321dand the components that are held together using screws322a-322dare configured to be coupled together by screwing housing piece209ato housing piece209busing screws218a-218c. Screws218a-218care configured to be inserted into corresponding openings of housing piece209aand corresponding threaded holes of housing piece209b, in that order. When housing piece209aand housing piece209bare coupled together and mounted on a corresponding caster, collar216is coupled to the assembled housing pieces using screws218d-218eand corresponding screw caps319d-319e.

FIGS.3B-Cillustrate possible dimensions shown for a cross-section of an embodiment for the caster assembly, in accordance with certain embodiments of the present disclosure.FIG.3Cillustrates the cross section taken at A as indicated inFIG.3B. In the cross-section shown inFIG.3C, the screws322a-dand biasing elements330band332bhave been removed for clarity. In some embodiments, a distance350between a centerline and upper pin329bmay be approximately in a range of 0.4 to 1.4 inches, such as 0.9 inches. In some embodiments, a horizontal distance352between the upper pin329band a left radial formation of the rear guard312bmay be approximately in a range of 0.05 to 0.7 inches, such as 0.344 inches. In some embodiments, a horizontal distance354between the upper pin329band a right radial formation of the rear guard312bmay be approximately in a range of 0.25 to 0.8 inches, such as 0.549 inches. In some embodiments, a distance356between the upper pin329band the lower pin327bmay be approximately in a range of 1.2 to 2.25 inches, such as 1.770 inches. In some embodiments, a vertical distance358between the upper pin329band a right radial formation of the rear guard312bmay be approximately in a range of 0.3 to 0.9 inches, such as 0.594 inches. In some embodiments, a vertical distance360between the upper pin329band a left radial formation of the rear guard312bmay be approximately in a range of 0.3 to 0.9 inches, such as 0.568 inches. In some embodiments, a length362of slot315bmay be approximately in a range of 0.25 to 1.0 inches, such as 0.650 inches. In some embodiments, a width364of slot315bmay be approximately in a range of 0.05 to 0.4 inches, such as 0.180 inches. In some embodiments, an angle366between the centerline and a line running through the center of slot315band upper pin329bmay be approximately in a range of 5 to 25 degrees, such as 10 degrees. In some embodiments, a vertical distance368between the bottom of the left and right radial formations and the bottom of the rear guard312bmay be approximately in a range of 1 to 4 inches, such as 2.367 inches. In some embodiments, a wheel diameter370may be approximately in a range of 3 to 7 inches, such as 4.921 inches. While several example dimensions have been provided above, it is to be understood that other dimensions are also contemplated. For example, if the wheel diameter is smaller or larger than indicated above, the dimensions may be appropriately scaled to suit the different size wheel. Further, other angles and dimensions are also suitable for the caster described herein and the examples above are not meant to be limiting, but instead illustrative of a possible caster embodiment.

FIG.4Aillustrates an internal side view of front guard210a, rear guard212a, and housing piece209a. InFIG.4A, front guard210aand rear guard212aare in a fully deployed state. In the fully deployed state, lower pins326aand327aare positioned at upper ends of each of lower slots311aand315a. Further, in the fully deployed state, upper pins328aand329a(which are not visible as they located behind respective biasing elements330aand332ainFIG.4A) are positioned at upper ends of each of upper slots313aand317a. The upper end of each slot refers to the end that is farther from the ground. The lower end of each slot refers to the end that is closer to the ground. As shown, body440aof front guard210ahas a first end442adisposed inside a perimeter of housing piece209aand second end444adisposed outside the perimeter of housing piece209a. The perimeter of housing piece209arefers to an area inside housing piece209awhen viewed from the side. In the fully deployed state, front guard210ahas a first clearance with the ground which is at a minimum. The clearance with the ground refers to a distance from the ground to second end444a, in which the distance is measured perpendicular to the ground surface.

Body440ahas a sidewall446aextending at least partially around a perimeter of body440a. Sidewall446arefers to a raised portion of body440awhich defines an inner cavity448abetween opposing portions of sidewall446a. Body440ahas a leading edge454aformed along a portion of sidewall446adisposed outside the perimeter of housing piece209a. The leading edge refers to an outward-facing portion of each guard which is configured to make the first contact with objects as medical equipment100is moved around on caster assemblies102. Leading edge454ais perpendicular to the ground surface to provide a larger surface area for objects to contact front guard210afrom the front. In certain other embodiments, leading edge454ais non-perpendicular to the ground surface. In certain embodiments, leading edge454ahas a surface profile (e.g., horizontal or vertical ridges, a grid pattern, or any suitable surface texture) to increase friction and prevent slipping between leading edge454aand contacting objects.

Body440ahas an outer face450aenclosing inner cavity448aon one side (e.g., on a side closer to housing piece209aas shown). Outer face450aextends between opposing portions of sidewall446a. Lower slot311aand upper slot313aare defined in outer face450a. Hook334ais disposed at first end442aof body440a. The upper end of biasing element330afits around hook334ato couple biasing element330ato front guard210a. A notch452ais formed through sidewall446aat first end442aof body440a. Notch452aprovides an opening for biasing element330bto extend through sidewall446ain order to couple to hook334a. As shown, biasing element330afits within inner cavity448a. The lower end of biasing element330afits around lower pin326ato couple biasing element330ato housing piece209a.

Rear guard212a, front guard210b, and rear guard212bare each constructed and arranged similar to front guard210a. For example, referring to rear guard212a(shown inFIG.4A), body441aof rear guard212ahas a first end443adisposed inside a perimeter of housing piece209aand a second end445adisposed outside the perimeter of housing piece209a. Body441ahas a sidewall447aextending at least partially around a perimeter of body441a. Body441ahas a leading edge455aformed along a portion of sidewall447adisposed outside the perimeter of housing piece209a. Leading edge455ais perpendicular to the ground surface to provide a larger surface area for objects to contact rear guard212afrom the rear. In certain other embodiments, leading edge455ais non-perpendicular to the ground surface. In certain embodiments, leading edge455ahas a surface profile (e.g., horizontal or vertical ridges, a grid pattern, or any suitable surface texture) to increase friction and prevent slipping between leading edge455aand contacting objects. As shown behind biasing element332a, body441ahas an outer face451aenclosing an inner cavity449aon one side (e.g., on a side closer to housing piece209aas shown). Outer face451aextends between opposing portions of sidewall447a. Lower slot315aand upper slot317aare defined in outer face451a. Hook336ais disposed at first end443aof body441a. The upper end of biasing element332afits around hook336ato couple biasing element332ato rear guard212a. A notch453ais formed through sidewall447aat first end443aof body441a. Notch453aprovides an opening for biasing element332bto extend through sidewall447ain order to couple to hook336a. As shown, biasing element332afits within inner cavity449a. The lower end of biasing element332afits around lower pin327ato couple biasing element332ato housing piece209a.

FIG.4Billustrates an internal side view of front guard210a, rear guard212a, and housing piece209a. InFIG.4B, rear guard212aremains in the fully deployed state, whereas front guard210ahas transitioned into a retracted state. As shown, front guard210ais in a fully retracted state. Note that, in certain embodiments, any state other than the fully deployed state may be considered as a retracted or a partially retracted state. Such a state may also be considered as a partially deployed state. As shown, contact between a portion of front guard210adisposed outside housing209a(e.g., leading edge454aor second end444a) and fixed object214causes front guard210ato transition into the retracted state. In the fully retracted state, lower pin326ais positioned at a lower end of lower slot311aand upper pin328a(which is located behind biasing element330ainFIG.4B) is positioned at a lower end of upper slot313a. In the retracted state, front guard210ais transitioned upwards against downward biasing force of biasing element330a. In the retracted state, front guard210ahas a second clearance with the ground which is greater than the first clearance shown inFIG.4A. InFIG.4B, which shows front guard in the fully retracted state, the second clearance is at a maximum. In the retracted state, biasing element330ais extended compared to the same biasing element in the deployed state. As shown inFIG.4B, biasing element330ais also extended compared to biasing element332a. The retraction of front guard210ais described in more detail below with respect toFIGS.5A-5D.

FIGS.5A-5Dillustrate motion of front guard210arelative to lower pin326aand upper pin328aduring contact with and subsequent movement over fixed object214. For clarity, all other components of caster assembly102are omitted fromFIGS.5A-5Dwith the exception of caster wheel101which is shown in phantom. As shown inFIG.5A, caster wheel101is positioned on the left side of fixed object214, and front guard210is in the fully deployed state. In the fully deployed state, lower pin326ais positioned at the upper end of lower slot311aand upper pin328ais positioned at the upper end of upper slot313a. Front guard210ais centered with respect to upper pin328adue to front guard210abeing biased downward in combination with the shape of upper slot313awhich converges at the upper end.

As shown inFIG.5B, caster wheel101has moved closer to fixed object214, and front guard210ahas transitioned into a first retracted state. Note that caster wheel101is still spaced from fixed object214in the position shown inFIG.5B. As shown, leading edge454aof front guard210ais in contact with a left side214aof fixed object214. Movement (e.g., retraction) of front guard210ais guided in first part by contact between a perimeter of lower slot311aand corresponding lower pin326aand in second part by contact between a perimeter of upper slot313aand corresponding upper pin328a. Lower slot311ahas a linear shape which is configured to confine translational motion of front guard210ato only two directions. In other words, a width of lower slot311ais about the same as a diameter of lower pin326aso that lower pin326acan only move in two directions (e.g., up and down) within lower slot311a. In contrast to lower slot311a, upper slot313ahas a non-linear shape which is configured to permit translational motion of front guard210ain any direction. In other words, a width and length of upper slot313aare both greater than a diameter of upper pin328aso that upper pin328acan move in any direction (e.g., up, down, left, and right) within upper slot313a. As shown, upper slot313ais triangular. Alternatively, upper slot313amay be square, rectangular, circular, or any other suitable non-linear shape.

The motion of upper slot313ain any direction relative to upper pin328aallows lower slot311ato rotate about a longitudinal axis of lower pin326ain addition to translating on the longitudinal axis of lower slot311a. Therefore, as front guard210acontacts left side214aof fixed object214at leading edge454a, a lateral force is exerted on front guard210acausing front guard210aand lower slot311ato rotate clockwise about the longitudinal axis of lower pin326a. Rotation of front guard210acauses a left side of sidewall446a(which corresponds to the perimeter of slot313a) to translate in contact with upper pin328a. The shape of upper slot313a(which diverges in a downward direction) and complementary angle of sidewall446acauses front guard210ato move upwards causing lower slot311ato translate in contact with lower pin326aas shown.

As shown inFIG.5C, caster wheel101has moved into contact with fixed object214, and front guard210ahas transitioned into a second retracted state which has a greater clearance with the ground compared to the first retracted state shown inFIG.5B. InFIG.5C, caster wheel101is in contact with an edge connecting side214aand top surface214bof fixed object214. ComparingFIGS.5B and5C, continued application of the lateral force on front guard210acontinues the clockwise rotation of front guard210aand lower slot311aabout the longitudinal axis of lower pin326awhich continues the upward movement of front guard210aas left side of sidewall446acontinues to translate in contact with upper pin328aand lower slot311acontinues to translate in contact with lower pin326a. As shown inFIG.5C, front guard210ais disposed completely within a perimeter of caster wheel101. Therefore, the retraction of front guard210ais at a maximum for the depicted movement of caster wheel101over fixed object214.

As shown inFIG.5D, caster wheel101has moved onto top surface214bof fixed object214, and front guard210ahas transitioned into the fully deployed state. Although not shown, after initial movement of caster wheel101onto top surface214bof fixed object214, second end444aof front guard210amoves into contact with top surface214b. At this point, the lateral force exerted on front guard210ais removed. Instead, a vertical force is exerted against second end444amaintaining front guard210ain a retracted state. Continued movement of caster wheel101along top surface214bprovides greater clearance between second end444aof front guard210aand top surface214bof fixed object214allowing front guard210ato transition to the fully deployed state shownFIG.5D. Although not shown, continued movement of caster wheel101in the direction shown may result in rear guard212bcontacting a right side of fixed object214as caster wheel101moves off fixed object214and back onto the ground surface. In certain examples, a trailing edge of rear guard212aopposite leading edge455aor second end445aof rear guard212a(shown inFIGS.4A-4B) may contact the right side of fixed object214causing rear guard212ato transition to a third retracted state.

Although not shown in operation, a structure and function of rear guard212a(shown inFIGS.4A-4B) mirrors that of front guard210asuch that rear guard212ais able to yield to fixed objects approaching from a direction opposite that which is shown inFIGS.5A-5D. In such examples, as rear guard212acontacts a right side of fixed object214at leading edge455a, a lateral force is exerted on rear guard212acausing rear guard212aand lower slot315ato rotate counterclockwise about a longitudinal axis of lower pin327a. Rotation of rear guard212acauses a right side of sidewall447a(which corresponds to the perimeter of slot317a) to translate in contact with upper pin329a. The shape of upper slot317a(which diverges in a downward direction) and complementary angle of sidewall447acauses rear guard212ato move upwards causing lower slot315ato translate in contact with lower pin327a.

Accordingly, certain embodiments described herein provide retractable guard assemblies that can be used in conjunction with caster wheels of an equipment. The retractable guard assemblies can be deployed to push objects, such as cables and hoses, aside when the equipment is being moved around. The retractable guard assemblies can also retract when the equipment is moved over fixed obstacles such as doorsills and elevator sills or non-fixed but difficult-to-move obstacles such as floor mats.

The foregoing description is provided to enable any person skilled in the art to practice the various embodiments described herein. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments. Thus, the claims are not intended to be limited to the embodiments shown herein, but are to be accorded the full scope consistent with the language of the claims.