Patent Publication Number: US-2022212353-A1

Title: On-demand pneumatic system for reconfigurable end effector

Description:
INTRODUCTION 
     The present disclosure generally relates to reconfigurable manufacturing tooling with pneumatic grippers, and more particularly relates to systems with reconfigurable workpiece gripping tooling where the tooling that grips and holds an object may include mechanical features to flexibly change the gripping geometry for handling parts of different physical dimensions, while concurrently controlling pneumatic power supply during reconfiguration. 
     Workpiece manipulation has generally been accomplished by manual activities which include an innate ability to control the adaptability to varying shapes of objects to be handled. When mechanization takes the place of manual activities, the ability to control the adaptability to geometric shape is subject to the inherent limitations imposed by the layout and rigidity of mechanical tooling structures. When a tool, such as the end-of-arm tooling/end effector of a robot uses pneumatic power to grip the object, further limitations arise due to the need to accommodate the pneumatic supply to each gripper. A pneumatic gripper may operate to clamp onto a workpiece, may include a vacuum cup to contain suction for holding the workpiece to be manipulated, or may otherwise operate by mechanically moving components under power supplied by vacuum and/or positive pressure. 
     When pneumatic tooling is reconfigurable for adapting to different part geometries, the ability to adapt to different part shapes is limited by the layout of the various pneumatic grippers. A need exists for expanded ability to handle a wide range of part geometries with the same end effector/tooling. In addition, the use of pneumatic gripping power is desirable due to its efficiency and availability. 
     Accordingly, the ability of a tooling device to conform to a variety individual workpiece geometries and to grasp complex shapes is desirable. In addition, the ability to do so in a non-complex, efficient and light-weight manner is desirable. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background. 
     SUMMARY 
     Systems are provided for on-demand pneumatic control in reconfigurable tooling, such as an end effector. 
     In a number of embodiments, a tooling system includes grippers configured to engage and grip a workpiece. The grippers are connected with arms. A lock releasably locks the arms in a number of positions, including a home position. A conduit circuit is coupled with the grippers to communicate a pneumatic power from a pneumatic power supply. A number of valves are disposed in the conduit circuit and each is repositionable between an open state and a closed state. The arm&#39;s valve is configured to move to the closed state in response to moving the respective arm to the home position. 
     In additional embodiments, the pneumatic power is configured to be delivered to the grippers through the arms. 
     In additional embodiments, the valves includes push buttons configured to engage the tooling system to move the valves to the closed state when the valve&#39;s respective arm is moved to the home position. 
     In additional embodiments, the arms are connected with branch rails through the locks. The pneumatic power is communicated to the grippers through the branch rails. 
     In additional embodiments, the valves comprise two-position, on-off mechanically actuated valves. 
     In additional embodiments, the tooling system is an end effector of a robot. A tool changer interface releasably couples the end effector with the robot. A repositioning fixture interface releasably couples the end effector with a repositioning fixture. 
     In additional embodiments, the robot is configured to reposition the end effector when the end effector is coupled with a repositioning fixture, and to move one or more of the arms to the home position. Moving an arm to the home position closes the respective valve and idles the respective gripper while others of the plurality of grippers remain active. 
     In additional embodiments, each arm is part of a branch of the tooling system that is configured to be repositionable with five degrees of freedom. 
     In additional embodiments, each arm is connected with its respective branch rail through a respective lock. The branch rails are connected with the cross bar through branch locks, each of which includes a block. Each valve includes a push button actuator that is forced against the respective block when the respective arm is moved to the home position. The valve is disposed in a closed state when the push button is forced against the block. 
     In additional embodiments, the valves are mechanically actuated two position on-off valves. 
     In a number of additional embodiments, a tooling system for gripping workpieces includes a plurality of grippers configured to engage and grip the workpieces. An arm is connected with each gripper and a lock is connected with each of the arms. The locks releasably lock the arms in a plurality of positions, including home positions. A bolt on each of the locks alternately releases and locks the arm in each of the plurality of positions. A conduit circuit is coupled with the plurality of grippers and communicates a pneumatic power to the grippers. A valve on each one of the arms is disposed in the conduit circuit before each one of the plurality of grippers. Each valve is repositionable between an open state and a closed state. When an arm is moved to the home position, the valve on the arm is moved to the closed state in response to moving the arm to the home position. 
     In additional embodiments, the pneumatic power is delivered to each of the plurality of grippers through the arms. 
     In additional embodiments, the valves each include a push button configured to engage the tooling system to move the valve to the closed state when the arm on which the valve is disposed is moved to the home position. 
     In additional embodiments, the arms are connected with branch rails through the locks. The pneumatic power is communicated to the plurality of grippers through the branch rails. 
     In additional embodiments, each valve comprises a two-position, on-off mechanically actuated valve. 
     In additional embodiments, the tooling system is an end effector of a robot. A tool changer interface releasably couples the end effector with the robot. A repositioning fixture interface releasably couples the end effector with a repositioning fixture. 
     In additional embodiments, the robot is configured to reposition the end effector when the end effector is coupled with a repositioning fixture, and to move at least one of the arms to the home position. Moving an arm to the home position closes the valve on the arms and idles the gripper on the arm, while others of the plurality of grippers remain active. 
     In additional embodiments, each arm is part of a branch of the tooling system that is configured to be repositionable with five degrees of freedom. 
     In additional embodiments, the arms are connected with branch rails through the locks. The branch rails are connected with a cross bar through branch locks that include blocks. The valves include push button actuators that are disposed against one of the blocks when the valve&#39;s arm is moved to the home position, moving the valve to the closed state. 
     In a number of other embodiments, a tooling system for gripping workpieces includes a master boom, a crossbar coupled with the master boom, and branch rails coupled with the crossbar and selectively repositionable relative to the crossbar. Swing arms are included, one of which is coupled with each of the branch rails. Each swing arm is repositionable relative to its respective branch rail. A plurality of pneumatic grippers are included, one of which is coupled with each swing arm. A valve is included on each swing arm and is disposed in a conduit circuit between a respective pneumatic gripper and a pneumatic power supply. Each valve is repositionable between an open state and a closed state. A tool changer interface is included on the master boom to releasably couple with the robot. A repositioning fixture interface is included on the master boom to releasably couple with a repositioning fixture. The robot is configured to reposition the branch arms and the swing arms when the repositioning fixture interface is coupled with the repositioning fixture, and to move at least one of the swing arms to the home position. Moving a swing arm to the home position closes the valve on the arm, and idles the pneumatic gripper on the arm, while others of the plurality of pneumatic grippers remain active. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The exemplary embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein: 
         FIG. 1  is a perspective illustration of a reconfigurable tooling device in the form of an end effector, in accordance with various embodiments; 
         FIG. 2  is a perspective illustration of a reconfiguration cell for the reconfigurable end effector of  FIG. 1 , in accordance with various embodiments; 
         FIG. 3  is a schematic diagram of the pneumatic system for the reconfigurable end effector of  FIG. 1 , in accordance with various embodiments; 
         FIG. 4  is a detail, perspective illustration of one branch of the reconfigurable end effector of  FIG. 1 , in accordance with various embodiments; 
         FIG. 5  is perspective illustration of a valve of the end effector branch of  FIG. 4 , in accordance with various embodiments; and 
         FIG. 6  is schematic diagram of the valve of  FIG. 5  in a normally open state, in accordance with various embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is merely exemplary in nature and is not intended to limit the application and uses. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. 
     In various embodiments as disclosed herein, an on-demand pneumatic system is included in a reconfigurable tool, such as an end effector. Individual grippers/branches may be selectively and independently activated or inactivated/idled as the tooling configuration requires. Reconfiguration of the tooling locates a number of pneumatic powered grippers in three-dimensional space to provide secure gripping and holding of workpieces that have a variety of complex/irregular shapes. Reconfiguration enables lifting and handling one large part or a number of smaller parts simultaneously, providing efficient use of the tooling and resulting in a highly flexible handling device. The on-demand pneumatic system enables idling some branches or grippers of the tooling when not used. For example, the physical shape of the parts being handled may not enable nesting multiple grippers in a pattern that matches the available positions for all of the grippers. In other examples, the shape of a part to be handled may not be best accommodated if gripper locations would result in overcrowded areas when all grippers are employed simultaneously. Idling grippers/branches includes shutting off the pneumatic power to the grippers of the idled branches, which is accomplished without affecting the other grippers in an interlinked pneumatic layout series of grippers. The use of a pushbutton actuated on/off valve to provide on-demand pneumatic power to each gripper individually provides the benefits of simplicity, low-cost and light-weight, without a need for sophisticated control system. The on-demand pneumatic control is automatically provided as a direct result of moving a branch to its homing or idling position during reconfiguration, without affecting the pneumatic power to the other branches. 
     Referring to  FIG. 1 , illustrated is a device referred to as tooling  100 , which is configured as a reconfigurable end effector, in accordance with various embodiments. In other embodiments, the tooling  100  may be referred to as end-of-arm tooling and in either case, may be configured for connection and manipulation by automated machinery. In additional embodiments, the tooling  100  may be configured for manipulation by machinery that is not automated, and/or may be configured for manual manipulation. 
     In the illustrated embodiment, the tooling  100 , as an end effector, includes a tool changer interface  102  for connection with automated machinery such as a robot as further described below. The tool changer interface  102  may include features for effecting releasable mechanical, pneumatic, and/or electric coupling as needed for the application. A master boom  104  extends from the tool changer interface  102  to a connector  106 . The connector  106  provides a coupling with a crossbar  108  that extends laterally and bi-directionally from the master boom  104 . The connector  106  fixes the crossbar  108  to the master boom  104  by at least one bolted shackle-type cap  110 . The lengths of the master boom  104  and the crossbar  108  are selected to accommodate the size of the parts to be lifted and handled. In other embodiments, more than one crossbar  108  may be included. 
     A number of branch rails  111 - 120  are connected with the crossbar  108  by joints, referred to as branch locks  122 . In the current embodiment, adjacent of the branch rails  111 - 120  extend in opposite directions from the crossbar  108 , with the exception of branch rails  115  and  116  disposed on opposite sides of the master boom  104 , which extend in a common direction. In other embodiments, other layout arrangements may be used. The joints are adjustable via the branch locks  122  to enable rotation  152  of the branch rails  111 - 120  relative to the crossbar  108 . In addition, the joints enable translation  156  of the branch rails  111 - 120  along the crossbar  108 . In the current embodiment, the branch locks  122  each include a bolt  124 , that when tightened, clamps the respective branch rail  111 - 120  to the crossbar  108  and when loosened, allows rotation/translation of the respective branch rail  111 - 120  relative to the crossbar  108 . Each branch lock  122  also includes a receiver opening  126 , such as for receiving a drive pin that drives movement of the respective branch rail when the bolt  124  is loosened. For example, the disclosure of commonly assigned U.S. Pat. No. 9,656,394 titled Robotic System with Reconfigurable End-effector Assembly, and granted May 23, 2017, is specifically incorporated herein by reference. In other embodiments, the branch locks  122  may be configured, such as with screw/gear mechanisms, to both lock and to rotate the branch rails  111 - 120  relative to the crossbar  108 . For example, the bolts  124 , or another drive element, may be driven to rotate the respective branch rail  111 - 120  relative to the crossbar  108 . 
     Each branch rail  111 - 120  carries a respective swing arm  131 - 140 , with each respective pair connected by a joint in the form of a swing lock  142 . The joints/swing locks  142  are adjustable to enable rotation  158  of the swing arms  131 - 140  relative to their respective branch rails  111 - 120 . The swing locks  142  also enable rotation  162  of the swing arms  131 - 140  relative to their respective swing lock  142 . In addition, the swing locks  142  enable translation  166  of the swing arms  131 - 140  along its respective branch rail  111 - 120 . In the current embodiment, the swing locks  142  each include a bolt  144 , that when tightened, clamps the respective swing arm  131 - 140  relative to its branch rail  111 - 120  and when loosened, allows rotation/translation of the respective swing arm  131 - 140  relative to its branch rail  111 - 120 . Each swing lock  142  also includes a receiver opening  146 , such as for receiving a drive pin that drives movement of the respective swing arm when the bolt  144  is loosened. In other embodiments, the swing locks  142  may be configured, such as with screw/gear mechanisms, to both lock and to rotate the swing arms  131 - 140 . 
     Each of the swing arms  131 - 140  carries a gripper  150  on its end opposite the respective swing lock  142 . The grippers  150  may be pneumatically operated in a variety of manners. In the illustrated embodiment, the grippers  150  are vacuum cups that grip parts using contained, internal negative pressure for lifting and manipulation of the parts by the tooling  100 . Each of the grippers  150  is carried with at least an adjustable five degrees-of-freedom. Through the branch locks  122 , the branch rails  111 - 120 , with their respective gripper  150  is rotatable  152  about the longitudinal axis  154  and translatable  156  along the longitudinal axis  154  of the crossbar  108 . Through the swing locks  142 , each gripper  150  is: rotatable  158  about the longitudinal axis  160  of the branch rails  111 - 120 ; rotatable  162  about an axis  164  that is perpendicular to the axis  160  and the axis  154 ; and translatable  166  along the axis  160 . The adjustments enable locating the grippers  150  in a variety of positions to engage with a variety of parts having a complex contoured shape and/or with plural parts simultaneously. 
     Each branch rail  111 - 120  is associated with/includes a reel  170 , which may be spring loaded to manage pneumatic tubing/hose that distributes pneumatic power in a daisy-chain fashion. This means each pneumatic gripper  150  is interconnected with the same distributed pneumatic power supply in an interlinked series, which may include parallel and/or in-series connections. The reels  170  are configured to take-up tubing slack and to deliver additional tubing length for accommodating adjustments made during reconfiguration of the tooling  100 . As illustrated in  FIG. 1 , the hosing is generally omitted for simplicity and clarity. However, in the schematic pneumatic diagram of  FIG. 3 , the circuit is illustrated including the tubing and other conduit components. 
     As illustrated in  FIG. 1 , the tooling  100  also includes a repositioning fixture interface  172  for engaging a fixture stand as described in more detail below in association with  FIG. 2 . The repositioning fixture interface  172  is fixed to the master boom  104  between the crossbar  108  and the tool changer interface  102 . The repositioning fixture interface  172  locates the tooling  100  relative to a fixture so that the branch locks  122  and the swing locks  142  may be operated to reposition the grippers  150  of the tooling  100 . 
     Referring additionally to  FIG. 2 , the tooling  100  is mounted to a repositioning fixture  180 . Generally, the tooling  100  is carried by automated machinery in the form of a robot  176 , which engages the tool changer interface  102 . In this reconfiguration cell  178 , the robot  176  has delivered the tooling  100  so that the repositioning fixture interface  172  engages with the repositioning fixture  180 , and the robot  176  has then disengaged from the tool changer interface  102 . The repositioning fixture  180  holds the tooling  100  while the robot  176  effects reconfiguration of the tooling  100  for picking up and manipulating the intended part or parts. The robot  176  has engaged with a repositioning tool  182 , which may have been acquired from a tool holder  181  on the repositioning fixture  180 , and is using the repositioning tool  182  to reconfigure the tooling  100 . The repositioning tool  182  may include a nut driver that loosens the bolts  124 ,  144 , a pin driver that engages the receiver openings  126 ,  146  and repositions the grippers  150  by moving the branch rails  111 - 120  and the swing arms  131 - 140  to their desired positions. The repositioning tool  182  then relocks the joints using its nut driver feature. 
     The pneumatic circuit  200  of the tooling  100  is illustrated in  FIG. 3 , to which reference is additionally directed. The circuit  200  distributes pneumatic power from a pneumatic power supply  202  at the robot  176  to the pneumatic grippers  150 . Each vacuum cup style gripper  150  is normally open to, and is interconnected with, each other gripper  150  and with the pneumatic power supply  202 , such as through the tool changer interface  102 . As a result, if a gripper  150  is not in contact with a part to be handled (such as illustrated in  FIG. 4 ), a vacuum leak would exist, if the pneumatic power to that gripper is not shut off. The pneumatic circuit  200  includes a main branch  204 . The main branch  204  comprises one or more pneumatic tubes which generally run along the master boom  104  of the tooling  100 . A side branch chain of tubes  211 - 215  and a side branch chain of tubes  216 - 220  are connected with the main branch  204 . In the current embodiment, the side branch chains  211 - 215  and  216 - 220  comprise pneumatic tubes that run from the main branch  204  to, and around, the reels  170 . The tubes  211 - 215  supply pneumatic power to the branches associated with the branch rails  111 - 115 . The tubes  216 - 220  supply pneumatic power to the branches associated with branch rails  216 - 220 . From the side branch chains via the tubes  211 - 215 /reels  170 , and the tubes  216 - 220 /reels  170 , the circuit  200  continues through the branch rails  111 - 120 . For example, the branch rails  111 - 120  comprise hollow structural tubes through which the pneumatic power is channeled. From the branch rails  111 - 120 , the pneumatic circuit  200  emerges and is channeled through pneumatic tubing  221 - 230 , each of which extends to a respective valve  232 . The valves  232  effect on-demand control the supply of pneumatic power to the grippers  150  as described in greater detail below. From the valves  232 , the pneumatic circuit  200  extends through tubing  241 - 250  and into the swing arms  131 - 140 . For example, the swing arms  131 - 140  comprise hollow structural tubes through which the pneumatic power is channeled to the grippers  150 . Through the pneumatic circuit  200 , pneumatic power is distributed to all of the pneumatic grippers  150  in a daisy-chain fashion. 
     Referring to  FIG. 4 , one branch  300  of the tooling  100  is illustrated in isolation. The branch  300  corresponds to the branch of  FIG. 1  with the branch rail  113  and is representative of each of the ten branches of the tooling  100  illustrated in  FIG. 1 . In general, the branch  300  includes the branch rail  113 , the branch lock  122 , the swing lock  142 , the swing arm  133 , the pneumatic tubing  223 ,  243 , the valve  232  and the pneumatic gripper  150 . The bolt  144  enables adjustment of the swing arm  133 . The incoming pneumatic supply from the side branch chain via tube  213  ( FIG. 3 ), enters through a fitting  302  and is communicated internally through the branch rail  113 . Another fitting  304  distributes the pneumatic power onward, in this case to the next branch in the chain, which is to the branch with the branch rail  111  shown in  FIG. 1 . 
     In the branch  300 , the pneumatic power passes internally through the branch rail  113  and exits through a fitting  306  for communication into and through tubing  223 . The tubing  223  includes a spiral segment  308  for expansion and contraction when the swing lock  142  and swing arm  133  are repositioned along the branch rail  113 . The tubing  223  is connected with a port  310  of the valve  232 . The tubing  243  is connected with a second port  312  of the valve  232 . The tubing  243  includes a spiral segment  314  for flexibility and is connected with the swing arm  133  by a fitting  315  to pass the pneumatic power into and through the swing arm  133  as a conduit. The pneumatic power is communicated through the valve  232  (when open), through the tubing  243  and into the swing arm  133 . The pneumatic power passes through the swing arm  133  and exits into the vacuum cup style gripper  150  providing a suction function. In this case, the individual illustrated gripper  150  is located to not be in contact with the part  252  being handled by the tooling  100  and gripper by others of the grippers  150 . Accordingly, the branch  300  is idled and the valve  232  is closed. 
     Referring to  FIGS. 5 and 6  along with  FIG. 4 , the valve  232  is a two-port, two position valve with an open state  316  and a closed state  318 . The valve  232  is mechanically actuated by a push button  320  actuator, and is spring  322  (internal in  FIG. 5 ), returned to its normally open state. As illustrated in  FIG. 4 , the swing lock  142  is moved to a home position, which forces the push button  320  against a block  324  on the branch lock  122  that actuates the valve  232  moving it to the closed state  318 . The block  324  extends from the branch lock  122  and may take a variety of forms such as a pin, an arm, a flat surface, or others, to engage the push button  320 . With the valve  232  closed, the pneumatic power is shut off to the swing arm  133  and to its gripper  150 , idling the branch  300 . The pneumatic power continues to pass on the adjacent branch through the fitting  304  and the other grippers  150  in the chain may remain active. Idling of the branch  300  may be accomplished by moving it to the home position during reconfiguration of the tooling in the reconfiguration cell  178  as shown in  FIG. 2 . The valve  232  is closed as a result of movement during the reconfiguration which actuates the push button  320  by engagement with the block  324 , without a need for additional action. 
     Through the embodiments disclosed herein, reconfigurable end of arm tooling with pneumatic powered grippers provides secure gripping and holding of workpieces that have a variety of complex/irregular shapes. The reconfigurable end of arm tooling is adaptable to handle both large and small parts, and enables idling some branches or grippers when not used, such as to make space for the others. Idling includes shutting off the pneumatic power to the grippers of the idled branches, which is accomplished by closing a valve without affecting the other grippers in a daisy-chained pneumatic layout. The pneumatic power is shut of to select grippers automatically as a result of moving the affected branch to its home position during routine reconfiguration of the tooling to adapt to the part or parts that will be lifted and manipulated. The valve is actuated to a closed state when the idled branch is moved to a home position by means of the valve&#39;s actuator engaging a part of the tooling as a result of reaching the home position. The valve is actuated without electrical power and without sophisticated controls. 
     While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes may be made in the function and arrangement of elements and/or steps without departing from the scope of the disclosure as set forth in the appended claims and the legal equivalents thereof.