Patent Publication Number: US-2017361472-A1

Title: Robot Cell

Description:
TECHNICAL FIELD 
     The present invention relates to a robot cell for demonstration purposes. 
     The cell includes a work centre, which, however, is not designed for use in an actual production process, but rather for use in activities of a purely demonstration nature. The cell may, for example, be used in sector fairs, in training operators, or else even in schools for exclusively didactic purposes. 
     BACKGROUND 
     In the specific field of industrial robots, cells of this type have appeared only with the spread, also in the industrial field, of smaller-sized manipulator robots. These robots usually have a maximum carrying capacity, at the wrist, of a few kilograms, and maximum dimensions, in height and length, of around one metre. The robots in question are commonly used for carrying out an extremely wide range of operations, in the framework of any industrial process, or as replacement for the operator or else in co-operation with, or support to, the operator. 
     In the light of what has been said above, it is clear that the normal use of a robot cell of the type in question is substantially different from that of a traditional work centre, envisaging, in particular, frequent displacements for reaching the various exhibition centres, which may be, as has been seen, industrial plants, schools, sector fairs, etc. 
     To facilitate transport and displacements, already today cells of this type have their own base mounted on swivel wheels so as to be displaceable and manoeuvrable. 
     SUMMARY 
     The object of the present invention is to provide a robot cell that will be improved as compared to the known cells, and in particular that will afford a series of advantages as regards the operations of transport and storage when not in use. 
     The object referred to is achieved via a robot cell comprising the characteristics specified in Claim  1 . 
     A further object of the present invention is to provide a work cell that has a particularly functional and flexible configuration, in the perspective of a use of the cell for multiple applications. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further characteristics and advantages of the invention will emerge from the ensuing description with reference to the annexed drawings, which are provided purely by way of non-limiting example and in which: 
         FIG. 1  is a perspective view of the robot cell described herein according to a possible embodiment, the cell being represented in an operative configuration thereof; 
         FIG. 2  illustrates the work cell of  FIG. 1 , in a compact configuration thereof; 
         FIG. 3  is a front view of the cell represented in  FIG. 2 , where some parts of the base of the cell have been removed in order to illustrate how the robot sets itself inside the base in the compact configuration assumed by the cell; 
         FIGS. 4A and 4B  are, respectively, a front view and a lateral view of the robot cell illustrated in  FIG. 1 , where also in this case some parts of the base of the cell have been removed to show the systems of movement of the robot and of the protective screen, which will be illustrated in detail in what follows; and 
         FIG. 5  is a schematic representation of the systems for movement of the robot and of the protective screen provided in the cell of  FIG. 1 . 
     
    
    
     In the ensuing description various specific details are illustrated aimed at providing an in-depth understanding of the embodiments. The embodiments may be obtained without one or more of the specific details, or with other methods, components, or materials, etc. In other cases, known structures, materials, or operations are not illustrated or described in detail so that various aspects of the embodiment will not be obscured. 
     The references used herein are provided merely for convenience and hence do not define the sphere of protection or the scope of the embodiments. 
     As has been seen above, the robot cell described herein constitutes a work centre for demonstration purposes. Illustrated in the figures is a preferred embodiment of the cell described herein. 
     In a way in itself known, the robot cell described herein, designated as a whole in the figures by the reference number  10 , comprises: 
     a robot  20 ;
 
a base  40 , which carries the robot  20  and defines a working surface P, where the robot operates; and
 
a protective screen  50 , configured for separating from outside the working surface P and the robot operating on the aforesaid surface.
 
     The robot  20  is a small-sized industrial manipulator robot. In the example illustrated, the robot is represented by the robot that is marketed by the present applicant under the brand name RACER 3®. 
     The cell described herein is characterized in that it is able to assume a configuration of minimum encumbrance, which has been specifically envisaged for transport of the cell and/or for storage thereof, for example in a warehouse, waiting to be used again. This configuration affords evident advantages, in particular, in terms of ease of transport, space saving, and reduction of the costs of transport and storage. Moreover, as will become evident in what follows, this configuration also enables integrity of the cell to be safeguarded during transport. 
     The cell is able to assume the configuration of minimum encumbrance referred to above, thanks to the following characteristics:
         the robot  20  is carried by a vertical-movement system and is vertically mobile between a raised position, in which it can operate on the working surface P, and a lowered position, in which it is set underneath the aforesaid surface and is contained within the base  40 ; and   the protective screen  50  is supported by a vertical-movement system and is vertically mobile between a raised, operative, position, in which it separates the working surface P and the robot  20  that operates on the aforesaid surface from outside, and a lowered position, in which it extends prevalently underneath the working surface P.       

     As regards the aforesaid characteristics, the configuration of minimum encumbrance referred to above is assumed by the cell when the robot and the protective screen are brought into the respective lowered position, as illustrated in  FIG. 2 . Since the screen  50  is able to slide out of the base  40 , in its lowered position it is set around the base  40 , thus enclosing it. 
     A normal operative configuration of the cell  10  is, instead, illustrated in  FIG. 1 . In this condition, the robot  20  and the protective screen  50  are each in the respective raised position. 
     It should be noted that the cell may envisage one and the same system for movement of the robot  20  and of the screen  50 , or else two independent systems as in the embodiment that will be illustrated hereinafter. 
     To come now to the detail of the various characteristics of the cell, in various embodiments, as in the one illustrated (see  FIG. 4 ), the base  40  is formed by a mount comprising a bottom frame  42 , a plurality of vertical uprights  44 , and a top frame  46 . 
     Mounted on the base frame  42  are one or more supporting plates that carry the driving assemblies that will be described in what follows. Mounted on the underside of the aforesaid plates are, instead, a series of swivel wheels  15 . 
     The top frame  46  carries at the top one or more plates  48 , which together define the aforementioned working surface P. Moreover carried on the same frame are a series of supporting plates (not visible), similar to the ones carried by the base frame  42 , which are arranged underneath the working surface P. 
     In various preferred embodiments, as in the one illustrated, the working surface P has an array of threaded holes  14  for fast fixing on the aforesaid surface of possible accessories or devices with which the robot  20  is designed to operate. Moreover provided on the aforesaid surface are a series of connectors S for providing the supplies necessary for said accessories or devices, such as electric-power supply or compressed-air supply. 
     The robot  20  is mounted on a stand  30  carried by a series of cylindrical guides  32  and by a jack  34  of a rotating-screw type. The internal-screw member is fixedly constrained to the stand  30 , whereas the external-screw member is constrained between the supporting plates of the two frames, the bottom or base frame  42  and the top frame  46 . At the bottom the external-screw member terminates within a block  35  for transmission of motion, which is fixed on a plate of the base frame  42 . In various embodiments, as in the one illustrated (see in particular  FIG. 5 ), this block  35  has, on the output shaft, a pulley  36  that is connected via a belt to a pulley  37  fitted on the output shaft of an electric motor  101 , which is also carried by a plate of the base frame  42 . 
     With reference to the cylindrical guides  32 , their respective guide bushings are directly associated to the stand  30 , whereas the cylindrical guide bars are fixed, at the bottom and at the top, to the plates of the frames  42  and  46 , respectively. 
     The motor  101  is designed to govern, through the jack  34 , the movement of lowering and raising of the stand  30 . This can in particular move between a position of minimum height (see  FIG. 3 ), which corresponds to the aforementioned lowered position of the robot  20 , and a position of maximum height (see  FIGS. 4A and 4B ), which corresponds to the aforementioned raised position of the robot. Appropriate end-of-travel elements of a mechanical, electrical, or else electromechanical type define these two end positions of the stand. 
     As may be seen in  FIG. 1 , the working surface P has a through opening P′, through which, from the stand  30 , the robot projects above the working surface P and through which the robot passes when it moves into its lowered position. In this position, the robot  20  is entirely contained within the base  40 . For its own part, the robot assumes, in this position, a completely contained condition so as to occupy as little space as possible and hence find sufficient space within the base, for its housing. The control unit of the cell may be configured for bringing the robot into this condition whenever it is set in an inoperative state. It should be noted that preferably—as envisaged in the embodiment illustrated—this robot is an articulated robot with at least four axes, which has at least three successive horizontal axes of articulation. This type of robot is in fact able to assume a completely collapsed position and is hence particularly suited to being used in the cell described herein. 
     With reference to the protective screen  50 , in various preferred embodiments, as in the one illustrated, it has a frame comprising two main uprights  52 , arranged symmetrically—with respect to a vertical plane orthogonal to the front side of the base—in a rear region of the working surface, and a cage structure, which is carried by these two uprights and encloses the working surface P. As will be seen in what follows, the two uprights  52  are carried by a vertical-movement system enclosed within the base  40 . 
     The cage structure mentioned, carried by the two uprights  52 , is constituted by a top horizontal frame  54 , fixed, via brackets (not visible), to the top ends of the uprights  52 , a series of vertical rods  56  that hang from the top frame, and a bottom frame  58  carried by the bottom ends of the rods  56  and having a shape substantially corresponding to that of the top frame  54 . 
     The two frames  54  and  58  define in plan view a closed profile that is larger than the overall section of the base  40  and, in particular, that surrounds the aforesaid base so that the overall structure described will be free to slide without any risk of interference with respect to the base  40 . 
     Mounted between the two frames  54  and  58  are a series of panels  55 , preferably made of transparent plastic material, for example polycarbonate, which come to close totally, on all sides, the volume enclosed within the structure. Preferably, on the front side the screen  50  has two mobile panels, which can slide as in the example illustrated (see  FIG. 1 ), or else swivel as in alternative embodiments, to enable access to the inside of the protective screen. Further panels  57  are mounted on the top frame  54  to define the roof of the screen  50 . 
     With reference now to the system for movement of the screen  50 , this comprises two lifting jacks  64 , each associated to one of the two main uprights  52 , and a series of guides  82  and  84 . 
     With reference to the jacks  64 , the internal-screw member (not illustrated) of each jack is fixed to the bottom end of the respective upright  52 . The screw member is, instead, constrained between the supporting plates of the two top and bottom frames  42  and  46 . At the bottom, the screw member terminates within a block  65  for transmission of motion, which is fixed on a plate of the base frame  42 . 
     In various embodiments, as in the one illustrated (see in this connection  FIG. 5 ), the transmission blocks  65  of the two jacks have on their output shaft respective pulleys  67  that are connected via a belt to two pulleys  73 ,  75  carried by one and the same horizontal shaft  72  constrained via supports, at portions thereof set at a distance apart from one another, to the plates of the bottom frame  42 . This shaft has, in a position between the two pulleys  73 ,  75 , a further pulley  77 , which is in turn connected via a belt to a pulley  79  fitted on the output shaft of an electric motor  103 . The motor  103  is also carried by a supporting plate of the bottom frame  42 . 
     The motor  103  is designed to govern, through the two jacks  64 , the movement of lowering and raising of the screen  50 . As has been seen above, the latter can move between the lowered position illustrated in  FIGS. 2 and 3  and the raised position of  FIGS. 4A and 4B . Appropriate end-of-travel elements of a mechanical, electrical, or else electromechanical type define these end positions of the screen  50 . 
     Associated to the two uprights  52  are two respective guides  82 , which are preferably prismatic, designed to guide the movement of sliding of the uprights with respect to the base  40 . The two vertical bars of the prismatic guide are mounted up against the two uprights  52  and are fixed at the bottom and at the top to the plates of the frames  42  and  46 , respectively. The sliding blocks of the guides are fixed to the bottom ends of the two uprights  52 . 
     Further guides, preferably of a cylindrical type, are, instead, associated to the front region of the screen  50 . These envisage cylindrical rods  84  that are suspended on the top frame  54  of the screen  50  and engage guide bushings (not visible) carried by the supporting plates of the top frame  46  of the base  40 . Possibly, further cylindrical guides may be associated, according to similar modalities, to the bottom frame  58  of the screen  50 . 
     The cell  10  comprises a unit for controlling the movement of the protective screen  50  and of the robot  20 . This movement may be activated by the operator through a control panel (not visible), which is preferably set on an outer side of the base  40 , in a bottom region thereof that is readily accessible even when the protective screen  50  is in its lowered position and surrounds the base itself. 
     As may be seen in  FIG. 1 , applied on the frame of the base are outer coating panels that together define a casing within which the various means for driving and control of the cell are enclosed. In this connection, in addition to the means already referred to, moreover contained within the base are a unit for control of the robot (not visible) and an inverter assembly  105  for driving the two electric motors  101  and  103 . 
     In various preferred embodiments, as in the one illustrated, the control unit is set within an extractable drawer  92  provided on the front side of the base. The base moreover envisages two further drawers  94 ,  96 , provided on its opposite sides, first of which carries a portable control device of the robot (the so-called “teach pendant”), and the second of which is, instead, equipped for installation of devices for communication with the robotized system (robot cabin), for example HMIs, PLCs, mini computers (e.g., Raspberry, Arduino, etc.), electronic boards, electrical accessories, etc. 
     The drawer  94  is equipped with an ergonomic support for the teach pendant, which is height-adjustable and slightly inclined backwards so as to enable the operator to operate conveniently on the teach pendant, even leaving it resting on the support. 
     At the front, the base  40  moreover has an extractable shelf  98 , designed to constitute an accessory resting surface, for example for carrying a laptop. 
     In various preferred embodiments, associated to the various drawers referred to, as also to the shelf, are electrical or electromechanical switches configured for changing their position, and the signals of these are used by the control unit of the cell for enabling movement of the protective screen only when the drawers and the shelf are in their closed configuration. 
     In various preferred embodiments, the cell  10  may moreover be equipped with a system for taking pictures in order to record what is occurring inside the cell during the demonstration activities, and the pictures taken may be displayed in real time on a separate display. This system and the display associated thereto increase accessibility to the cell and exploitation of the demonstration activities conducted therein, and may advantageously be used above all in the cases where the public that is present at the demonstration exceeds a certain number of people so that some could have a poor direct view. Preferably, the shooting system in question has at least one camera mounted in an overhead position on an inner side of the screen  50 . The cell has a series of connectors for direct connection of the camera to an external display and possibly also for concomitant connection of the camera itself to a laptop. 
     Of course, without prejudice to the principle of the invention, the details of construction and the embodiments may vary, even significantly, with respect to what has been illustrated herein purely by way of non-limiting example, without thereby departing from the scope of the invention, as is defined by the annexed claims. In this connection, it should be noted that, instead of the screw jacks referred to above, it is possible to envisage jacks of some other type, for example fluid-operated jacks. Likewise, the types of guide used for guiding movement of the stand  30  and of the screen  50  may also vary from the ones indicated. 
     As anticipated above, the cell  10  may in any case envisage a vertical-movement system common for the robot  20  and the screen  50 . With reference to the embodiment illustrated above, for example, the cell may present only the jacks  64  that drive the movement of the screen  50 , and, in this case, the stand  30  is then fixedly constrained via brackets to the uprights  52  of the screen  50 , so that also this can be moved by the jacks. 
     Finally, it should be noted that, instead of the jacks in question, it is also possible to envisage completely mechanical devices operating by way of counterweights.