Patent Publication Number: US-2022227172-A1

Title: Retractable Furniture Caster System

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. § 119 of U.S. Provisional Patent App. No. 63/139,251, filed Jan. 19, 2021, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     In recent years, there has been a trend in the furniture design industry to improve the mobility of furniture for use in multi-functional, temporary use, or flex spaces. For example, in the context of rental apartment furniture designs, there has been a trend of converting a stationary kitchen island to a movable kitchen island table in new apartment developments. One reason for this is to provide better flexibility within the dwelling unit for alternative uses of the kitchen island, such as using the island as a food preparation table, a dining table, a desk, an entertaining bar, a crafts table, or various other uses. Given this trend, there continues to be a need to develop furniture with better mobility so that the furniture can be more easily moved throughout the dwelling to serve multiple different functions. 
     Overview 
     Disclosed herein is new technology for providing improved mobility to an article of furniture. 
     In one aspect, the disclosed technology may take the form of a system comprising: (i) a plurality of furniture caster assemblies, each furniture caster assembly of the plurality of furniture caster assemblies respectively comprising (a) a housing comprising one or more side walls defining an interior space of the housing, wherein the housing is configured to mechanically couple to a respective furniture leg of an article of furniture comprising a plurality of legs, (b) a furniture caster comprising at least one rolling component, wherein the furniture caster is positioned at least partially within the interior space of the housing and movable between an extended position in which the at least one rolling component at least partially extends outside of the interior space of the housing and a retracted position in which the furniture caster is retracted further into the interior space of the housing relative to the extended position, and (c) a push-pull cable mechanically coupled to the furniture caster; and (ii) at least one actuator mechanically coupled to the push-pull cables, wherein the actuator is configured to (a) when actuated, apply a pushing force to the push-pull cables, thereby causing the furniture casters to transition from the retracted position to the extended position and (b) when not actuated, remove the applied pushing force from the push-pull cables, thereby causing the furniture casters to transition from the extended position to the retracted position. 
     In another aspect, the disclosed technology may take the form of an article of furniture comprising: (i) a plurality of furniture legs each comprising a respective bottom surface configured to interface with a floor or ground surface; (ii) a plurality of furniture caster assemblies, each furniture caster assembly of the plurality of furniture caster assemblies respectively comprising (a) a housing comprising one or more side walls defining an interior space of the housing, wherein the housing is mechanically coupled to a respective furniture leg of the plurality of legs, (b) a furniture caster comprising at least one rolling component, wherein the furniture caster is positioned at least partially within the interior space of the housing and movable between an extended position in which the at least one rolling component at least partially extends below the respective bottom surface of the respective furniture leg and a retracted position in which the at least one rolling component is positioned entirely above the respective bottom surface of the respective furniture leg, and (c) a push-pull cable mechanically coupled to the furniture caster; and (iii) at least one actuator mechanically coupled to the push-pull cables, wherein the actuator is configured to (a) when actuated, apply a pushing force to the push-pull cables, thereby causing the furniture casters to transition from the retracted position to the extended position and (b) when not actuated, remove the applied pushing force from the push-pull cables, thereby causing the furniture casters to transition from the extended position to the retracted position. 
     One of ordinary skill in the art will appreciate these as well as numerous other aspects in reading the following disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features, aspects, and advantages of the presently disclosed technology may be better understood with regard to the following description, appended claims, and accompanying drawings, as listed below. A person skilled in the relevant art will understand that the features shown in the drawings are for purposes of illustrations, and variations, including different and/or additional features and arrangements thereof, are possible. 
         FIG. 1  depicts a retractable furniture caster system according to an example embodiment. 
         FIG. 2  depicts a top view, side view, and bottom view of a furniture caster assembly of the retractable furniture caster system of  FIG. 1  according to an example embodiment. 
         FIG. 3  depicts the furniture caster assembly of  FIG. 2  installed into a furniture leg according to an example embodiment. 
         FIG. 4  depicts an actuator assembly of the retractable furniture caster system of  FIG. 1  according to an example embodiment. 
     
    
    
     The drawings are for the purpose of illustrating example embodiments, but those of ordinary skill in the art will understand that the technology disclosed herein is not limited to the arrangements and/or instrumentality shown in the drawings. 
     DETAILED DESCRIPTION 
     As noted above, disclosed herein is new technology for providing improved mobility to an article of furniture. Existing techniques for improving the mobility of furniture may involve affixing a set of casters to the legs of the furniture. However, this technique may negatively impact the design aesthetic of the furniture. For instance, some consumers may find the visual appearance of casters to be unappealing. To help address these or other issues, the technology disclosed herein is directed toward a retractable furniture caster system that allows the casters to transition to an extended position for rolling on the ground when it is desirable to move the furniture to a new location, and allows the casters to transition to a retracted position when it is no longer desirable to move the furniture. While in the retracted position, the casters may be out of sight so that they do not affect the design aesthetic of the furniture. 
     The following disclosure makes reference to the accompanying figures and several example embodiments. One of ordinary skill in the art should understand that such references are for the purpose of explanation only and are therefore not meant to be limiting. Part or all of the disclosed systems, devices, and methods may be rearranged, combined, added to, and/or removed in a variety of manners, each of which is contemplated herein. 
     I. Example Retractable Furniture Caster Systems 
     Turning now to the figures,  FIG. 1  depicts an example retractable furniture caster system  100  that may be used to improve the mobility of an article of furniture. As used throughout this disclosure, the term “caster” refers to any rolling component that can be mounted to an article of furniture and used for the support and movement of the article of furniture, and the term “rolling component” refers to a wheel, a rotating ball (e.g., roller ball), or any other rollable component that can be used in a caster for the support and movement of an article of furniture. The retractable furniture caster system  100  may be a standalone system that a consumer may separately install into an existing article of furniture, or the retractable furniture caster system  100  may be integrated into an article of furniture as part of the manufacturing process of the furniture. The retractable furniture caster system  100  may be integrated with various types of furniture including, but not limited to, tables, chairs, desks, cabinets, dressers, bookcases, or beds. 
     As shown, the retractable furniture caster system  100  includes a number of caster assemblies  102  including caster assembly  102   a,  caster assembly  102   b,  caster assembly  102   c,  and caster assembly  102   d.  While  FIG. 1  depicts the retractable furniture caster system  100  as including four caster assemblies  102 , it should be understood that the retractable furniture caster system  100  may include additional or fewer caster assemblies  102 . In practice, the number of caster assemblies  102  included in the retractable furniture caster system  100  may depend on the number of furniture legs of the article of furniture and may be equal to the number of furniture legs. For instance, when the retractable furniture caster system  100  is used to improve the mobility of a three-legged table, the retractable furniture caster system  100  may include three caster assemblies  102 , and when the retractable furniture caster system  100  is used to improve the mobility of a four-legged desk, the retractable furniture caster system  100  may include four caster assemblies  102 . Examples of other furniture types with differing numbers of legs are contemplated herein as well. 
     Each caster assembly  102  includes a housing  104 , a caster  106 , and a push-pull cable  108 . For instance, caster assembly  102   a  includes housing  104   a,  caster  106   a,  and push-pull cable  108   a.  Caster assembly  102   b  includes housing  104   b,  caster  106   b,  and push-pull cable  108   b.  Caster assembly  102   c  includes housing  104   c,  caster  106   c,  and push-pull cable  108   c.  And caster assembly  102   d  includes housing  104   d,  caster  106   d,  and push-pull cable  108   d.  As explained in further detail below in connection with  FIGS. 2 and 3 , the housing  104  of each caster assembly  102  is configured to mechanically couple to one of the legs of the article of furniture, the caster  106  of each caster assembly  102  is movably positioned within the housing  104 , and the push-pull cable  108  of each caster assembly  102  is mechanically coupled to the caster  106 . As used herein, “mechanically coupled” may refer to any means of attaching, securing, or fastening one object to another and may include either permanent or reversible means of doing so. 
     As further shown in  FIG. 1 , the retractable furniture caster system  100  may include an actuator assembly  110 . As explained in further detail below in connection with  FIG. 4 , the actuator assembly  110  includes an actuator  112  mechanically coupled to the push-pull cables  108 . In operation, when the actuator  112  is actuated, the actuator assembly  110  exerts a pushing force on the push-pull cables  108 . The push-pull cables  108  transfer this pushing force to the casters  106 , thereby pushing the casters  106  out of the housing  104  until the casters  106  are extended at least partially below the bottom surfaces of the furniture legs. In this extended configuration, the article of furniture may be rolled around on the casters  106 . When the actuator  112  is no longer actuated, the actuator assembly  110  removes the pushing force exerted on the push-pull cables  108  (and in some examples may exert a pulling force on the push-pull cables  108 ). With the pushing force removed, the weight of the article of furniture and/or any pulling force exerted on the push-pull cables  108  by the actuator assembly  110  causes the casters  106  to retract back into the housing  104  and above the bottom surfaces of the furniture legs, thereby causing the furniture legs to contact the floor or ground surface and become stationary. 
     Turning now to  FIGS. 2 and 3 , the components of the caster assemblies  102  and their functions will now be explained in further detail.  FIG. 2  depicts a top view  202 , a side view  204 , and a bottom view  206  of one of the caster assemblies  102 , while  FIG. 3  depicts a cutaway diagram  300  of one of the caster assemblies  102  that has been installed inside of a furniture leg  302 . 
     As noted above, the caster assembly  102  includes a housing  104 , and the caster  106  is movably positioned within the housing. To facilitate this, the housing  104  may include one or more sidewalls  208  that define an interior space  210  of the housing  104 . The interior space  210  may be large enough to contain the caster  106 , and the caster  106  may be movable within the interior space  210 . For instance, the caster  106  may be unsecured to the housing  104  and may be capable of moving vertically within the interior space  210 . 
     As further noted above, the caster  106  may move within the housing  104  due to the push-pull cable  108  exerting a force on the caster  106 . For instance, the push-pull cable  108  may include an outer conduit  109  and a cable  111  housed within the conduit  109 . The actuator  112 , when actuated, may exert a pushing force on the cable  111 , pushing the cable  111  through the conduit  109 . The cable  111  may be mechanically coupled to the caster  106  such that, when the actuator  112  exerts the pushing force on the cable  111 , the cable  111  transfers the pushing force to the caster  106 . To facilitate this, one end of the housing  104  may include a cable receiving block  212 . The conduit  109  may be fixed to the cable receiving block  212  (e.g., via a fitting of the push-pull cable  108  or the like), while the cable  111  may pass through an opening  214  in the cable receiving block  212  and mechanically couple to the caster  106 . While the entire length of the push-pull cable  108  is not shown in  FIGS. 2 and 3  for simplification purposes, it should be understood that the opposite end of the push-pull cable  108  that is not depicted in  FIGS. 2 and 3  is mechanically coupled to the actuator assembly  110  as depicted in  FIG. 1  and as described in further detail below in connection with  FIG. 4 . 
     As shown in  FIG. 3  and in the bottom view  206  of the caster assembly  102 , at the other end of the housing  104  opposite the cable receiving block  212 , the housing  104  may include a foot  216  having an opening  218  through which at least a portion of the caster  106  may extend when pushed out of the housing  104 . For instance, the caster  106  may include at least one rolling component  105  and a caster block  107 , and the opening  218  may be configured to allow the rolling component  105  to pass through but not the caster block  107 . The rolling component  105  may take various forms and may include a roller ball, a wheel, or any other rollable component that can be used for rolling articles of furniture. In order to allow the rolling component  105  to extend through the foot  216  of the housing  104 , the opening  218  in the foot  216  may be larger than the rolling component  105  but smaller than the caster block  107 . In this manner, the foot  216  of the housing  104  may allow the rolling component  105  to extend through the opening  218  out of the bottom of the housing  104  while blocking the caster block  107  and preventing the caster  106  from being pushed entirely out of the bottom of the housing  104 . 
     As further noted above, each of the caster assemblies  102  may be configured to mechanically couple to a respective leg of the article of furniture. This coupling may be achieved in various ways. In some examples, the caster assemblies  102  may be configured to be inserted inside the furniture legs. For example, as shown in  FIG. 2 , the housing  104  of the caster assembly  102  may include protruding fins  220 . An outside diameter of the fins  220  may be larger than an inside diameter of an interior space of the furniture leg such that, when the caster assembly  102  is inserted into the furniture leg, the fins  220  are compressed against the interior of the furniture leg and held in place by friction. However, this example is merely illustrative, and other mechanical coupling techniques are contemplated herein as well. For instance, the caster assembly  102  may be coupled to the furniture leg using any attaching, securing, or fastening techniques apparent to a person of ordinary skill in the art. Further, the caster assembly  102  need not be inserted into an interior portion of the furniture leg but may alternatively be coupled to an outside portion of the furniture leg. 
     Turning now to  FIG. 4 , the components of the actuator assembly  110  and their functions will now be explained in further detail. As noted above, the actuator assembly  110  includes an actuator  112  that is mechanically coupled to the push-pull cables  108 . In line with the discussion above, the push-pull cables  108  may include an outer conduit portion  109  and an inner cable portion  111  configured to slide through the conduit  109 . In particular, push-pull cable  108   a  may include outer conduit  109   a  and inner cable  111   a,  push-pull cable  108   b  may include outer conduit  109   b  and inner cable  111   b,  push-pull cable  108   c  may include outer conduit  109   c  and inner cable  111   c,  and push-pull cable  108   d  may include outer conduit  109   d  and inner cable  111   d.  While the entire lengths of the push-pull cables  108  are not shown in  FIG. 4  for simplification purposes, it should be understood that the opposite ends of the push-pull cables  108  that are not depicted in  FIG. 4  are mechanically coupled to the caster assemblies  102  as described above in connection with  FIGS. 1-3 . 
     In order to mechanically couple the actuator  112  to the push-pull cables  108 , the actuator assembly  110  may include a cable push block  402 . The push block  402  includes a fixed portion  404  and a slidable portion  406 . The fixed portion  404  may be immovably affixed to the article of furniture, for example to an underside of the furniture, and the slidable portion  406  may be movably coupled to the fixed portion  404  and configured to slide along a single axis relative to the fixed portion  404 . The outer conduit  109  of the push-pull cables  108  may be affixed to the slidable portion  406  of the cable push block  402 , for instance, via fittings  408  of the push-pull cables  108 . The inner cables  111  of the push-pull cables  108  may extend through the fittings  408  and be affixed to the fixed portion  404  of the push block  402  at respective terminals  410 . The terminals  410  may be separated from the fittings  408  by one or more springs  412 . 
     In operation, the actuator  112  may be configured to pull the slidable portion  406  of the push block  402  such that the fittings  408  are pulled toward the terminals  410 . This pulling motion on the fittings  408  (and consequently on the outer conduit portions  109  of the push-pull cables  108 ) effects a pushing force on the inner cables  111  of the push-pull cables  108 . And because the opposite ends of the inner cables  111  are coupled to the casters  106  of the caster assemblies  102 , this pushing force is transferred to the casters  106 , thereby causing the casters  106  to transition from a retracted position to an extended position as described above. Conversely, when the actuator  112  is released or otherwise no longer actuated, the springs  412  push the slidable portion  406  and the fittings  408  back to their previous position. This pushing motion on the fittings  408  (and consequently on the outer conduit portions  409  of the push-pull cables  108 ) effects a pulling force on the inner cables  111  of the push-pull cables  108 . Likewise, because the opposite ends of the inner cables  111  are coupled to the casters  106  of the caster assemblies  102 , this pulling force is transferred to the casters  106 , thereby causing the casters  106  to transition from the extended position to the retracted position as described above. 
     In order for the inner cables  111  to effectively transfer the pushing force to the casters  106 , the inner cables  111  may be designed to withstand a sufficient amount of compressive force without buckling. The sufficient amount of compressive force may vary across different applications. Namely, the sufficient amount of compressive force may depend on both the weight of the article of furniture and the number of furniture legs. For instance, consider an example in which the retractable furniture caster system  100  described herein is integrated into a four-legged table weighing one hundred pounds. Assuming a uniform weight distribution, in order to push the casters  106  into the extended position and lift the table off the ground, each of the casters  106  and their attached inner cables  111  would have to be capable of supporting, at a minimum, twenty-five pounds of force (i.e., one fourth of the table weight, which is distributed across the four casters  106  in the four table legs). As such, when determining which materials to use for the inner cables  111 , one should consider the amount of force that the inner cables  111  will be subjected to. For heavier furniture, it may be desirable to use higher tensile strength materials for the inner cables  111 , such as solid core steel cables. Whereas, for lighter furniture, lower tensile strength materials, such as braided metals, may be used. 
     The actuator  112  may take various forms and may be configured to pull the slidable portion  406  of the push block  402  in various ways. As shown in  FIG. 4 , the actuator  112  may include a handle that acts as a lever. The handle may be coupled to one end of yet another push-pull cable  414  having an outer conduit  416  affixed to the fixed portion  404  of the push block  402  and an inner cable  418  affixed to the slidable portion  406  of the push block  402 . In this manner, when the handle is pulled in the direction shown by arrow  420 , the handle exerts a pulling force on the inner cable  418  and thus also on the slidable portion  406  of the push block  402 . 
     As further shown in  FIG. 4 , the actuator assembly  110  may be affixed to an underside  422  of an article of furniture so that the actuator assembly  110  remains out of sight, thereby preserving the aesthetic effect of the furniture. Likewise, the push-pull cables  108  may be routed to the respective legs of the article of furniture along the underside  422  of the furniture. Upon reaching the furniture legs, the push-pull cables  108  may be respectively routed into interior portions of the furniture legs (e.g., through respective openings in the legs). The push-pull cables  108  may be further routed inside the legs through the interior portions and down to the respective caster assemblies  102  where the cables  108  may be mechanically coupled to the housings  104  and the casters  106  of the caster assemblies  102  as described above in connection with  FIGS. 1-3 . 
     Additionally, the actuator  112  may be positioned on the underside  422  of the furniture such that the handle of the actuator  112  is near an edge  424  of the article of furniture. The edge  424  may be an edge that is typically gripped by a person when moving the article of furniture, and the handle may be positioned close enough to the edge  424  so that when a person grips the edge  424 , the person may concurrently grip the handle of the actuator  112 . For instance, the handle may be positioned within one to three inches of the edge  424  of the furniture, but other examples are possible as well. With such an arrangement, a person can grab the handle and actuate the actuator  112  using the same or similar grip that the person would otherwise use to manually lift or move the furniture without the assistance of the retractable furniture caster system  100 . 
     II. Other Design Considerations 
     Various aspects of the retractable furniture caster system  100  described herein may take different forms than those described above. For instance, in some examples, the actuator  112  may take the form of an electric motor such as a DC motor, an AC motor, a servo motor, a linear motor, or a stepper motor. In such examples, the motor may be coupled to a power supply, such as a battery or a wall power outlet. 
     The motor may be configured to function in a similar manner as the manual actuator depicted in  FIG. 4 . For instance, the motor may be mechanically coupled, for instance via a gearbox or the like, to the slidable portion  406  of the cable push block  402 . When activated (e.g., by supplying power to the motor), the motor may pull the slidable portion  406  of the push block  402 , thereby pushing the inner cables  411  through the conduit  409 , causing the casters  106  to extend through the bottom of the housing  104 , and lifting the furniture legs off the ground. 
     In other examples, the motor may be one of multiple motors that function differently than the manual actuator depicted in  FIG. 4 . For instance, in some examples, the retractable furniture caster system  100  may include a separate electric motor for each respective furniture leg of the article of furniture. Each motor may be mechanically coupled, for instance via a gearbox, to one of the caster assemblies  102 . When a given motor is activated (e.g., by supplying power to the motor), the motor may generate a linear actuation force on the caster  106  in the coupled caster assembly  102  that causes the caster  106  to extend through the bottom of the housing  104  and lift the furniture leg off the ground. The multiple motors, each positioned in a different furniture leg, may be coupled to the same activation source (e.g., a single switch that controls power to the motors) so that the motors can be activated concurrently to lift all of the furniture legs off of the ground. Other example design variations are possible as well. 
     III. Conclusion 
     Example embodiments of the disclosed innovations have been described above. Those skilled in the art will understand, however, that changes and modifications may be made to the embodiments described without departing from the true scope and spirit of the present invention, which will be defined by the claims. 
     Further, to the extent that examples described herein involve operations performed or initiated by actors, such as “persons,” “humans,” “operators,” “users,” or other entities, this is for purposes of example and explanation only. The claims should not be construed as requiring action by such actors unless explicitly recited in the claim language.