Robotic cleaning device with retractable side brush

Abstract

A robotic cleaning device having a main body, a propulsion system configured to move the robotic cleaning device over a surface to be cleaned, a controller configured to control the propulsion system to move the robotic cleaning device over the surface to be cleaned, at least one rotatable side brush arranged to sweep debris from the surface to be cleaned, and a mechanism configured to at least partly retract the at least one rotatable side brush into a space arranged inside the main body upon receiving a control signal from the controller, such that the rotatable side brush is moved out of contact with the surface to be cleaned.

1 . A robotic cleaning device comprising:
 a main body;   a propulsion system configured to move the robotic cleaning device over a surface to be cleaned;   a controller configured to control the propulsion system to move the robotic cleaning device over the surface to be cleaned;   at least one rotatable side brush arranged to sweep debris from the surface to be cleaned; and   a mechanism configured to at least partly retract the at least one rotatable side brush into a space arranged inside the main body upon receiving a control signal from the controller, such that the rotatable side brush is moved out of contact with the surface to be cleaned.   
     
     
         2 . The robotic cleaning device of  claim 1 , wherein the mechanism comprises:
 a retractable member coupled to the at least one rotatable side brush and arranged to retract the at least one rotatable side brush into the space; and   an actuator arranged to move the retractable member into, or out of, the space upon receiving a control signal from the controller.   
     
     
         3 . The robotic cleaning device of  claim 1 , wherein the at least one rotatable side brush is configured to be retractable into the space inside the main body in an axial direction with respect to a rotational axis of the side brush. 
     
     
         4 . The robotic cleaning device of  claim 3 , wherein the space is cylindrically shaped and the mechanism comprises:
 a threaded rod located in the cylindrically shaped space;   an annular threaded member to which the at least one rotatable side brush is attached, the annular threaded member being arranged to engage with the threaded rod; and   an actuator configured to rotate the threaded rod;   wherein a diameter of the cylindrically shaped space is adapted to a dimension of the at least one rotatable side brush such that friction is created between the side brush and an interior of the cylindrically shaped space, thereby at least partly preventing the at least one rotatable side brush from rotating when in contact with the interior; wherein   said friction causes the annular threaded member to move along the threaded rod to extend out from the space in order to have the at least one rotatable side brush rotate and sweep the debris from the surface to be cleaned upon the threaded rod rotating in a first direction, the threaded annular member moving along the threaded rod until it reaches an end member of the threaded rod preventing the annular threaded member to move out of threaded engagement with the threaded rod; and   friction between the at least one rotating side brush and the surface to be cleaned causes the annular threaded member to move along the threaded rod to retract into the space upon the threaded rod rotating in a second direction.   
     
     
         5 . The robotic cleaning device of  claim 4 , wherein the mechanism further comprises:
 a spring arranged between the annular threaded member and the end member.   
     
     
         6 . The robotic cleaning device of  claim 4 , further comprising:
 an opening in a bottom side of the main body via which debris is removed from the surface, wherein the at least one rotatable side brush is arranged adjacent to the opening.   
     
     
         7 . The robotic cleaning device of  claim 2 , wherein the actuator comprises a motor. 
     
     
         8 . The robotic cleaning device of  claim 1 , wherein the robotic cleaning device comprises a robotic vacuum cleaner, a robotic sweeper or a robotic floor washer.