Labelling robot with shock absorbing members

Abstract: A pneumatic labelling robot system comprising a shock absorbing device comprising first and second shock absorbing members. The first absorbing member is provided with a shock adjustment member (40) having a piston rod (44) at the other end of a guide rod (11) which moves with the movement of a suction plate (15) with the other end of said piston rod (44) being in contact, if required, with the contacting portion of a main unit (1). The second absorbing member is a combination of three members, i.e. a rubber made shock absorbing member (26), a spring (30) wound on a piston rod (29) attached to the rubber made shock absorbing member and an auxiliary spring (32), each of the three members being connected to each other.

Description: The invention relates to a labelling robot of the type comprising a suction plate located on a main unit for picking up and applying an adhesive label to an object. A labelling robot of this type is known from DE-A-2347445. Said conventional labelling robot does not comprise any means for absorbing the impact energy which is generated at the moment of attachment of a label. It is therefore the object of the present invention to provide shock absorbing means so as to absorb the impact energy generated at the moment of applicating a label adhered to a suction plate on to an object to be labelled. The above object is achieved by the subject matter of the attached patent claim. The inventive pneumatic labelling robot is provided with a label sucking and sticking system executing one cycle comprising a vertical down stroke of the labelling robot's head for sucking a label, a subsequent label sucking action and a vertical upstroke of the head to the object to which the label is to be stuck. Thereafter a rotational movement to the horizontal and a horizontal advance stroke for the purpose of sticking the label on to the object. After the termination of the label sucking action a horizontal retraction stroke is effected as well as a rotational movement down to the vertical. The inventive labelling robot comprises a variety of electrical circuits connected to limit switches. Furthermore thses electrical conduits of the limit switches are connected to a sequence controller. The air circuits for effecting the afore-mentioned strokes and the suction circuit for said suction action are connected to an air control box which is connected to said sequence controller. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a view showing the overall configuration of a labelling robot according to the present invention in which the suction plate is lowered and a label attached thereto by suction force; Figure 2 also is a view of the overall configuration of the labelling robot of the present invention, showing the label on the suction plate being stuck on an object; Figure 3 is a block diagram showing the sequence of functions of the labelling robot; Figure 4 is an explanatory diagram of the sequence of functions; Figure 5 is a perspective view of a composite label; Figure 6 is a perspective view showing a suction plate for large labels; Figure 7 is a perspective view showing a suction plate for normal labels; Figure 8 is a cross-sectional view showing a portion of a suction element provided with a suction pad which is screwed to the suction plate; Figure 9A is a view of the reverse side of a suction plate; Figure 9B is a side view of the suction plate of Figure 9A, with the main portions shown in cross-section; Figure 10 is a cross-sectional view of the head portion of the labelling robot, showing the suction plate fastening means, the connecting means, and the like; and Figure 11 is a cross-sectional side view of the main parts of a shock adjustment member. DESCRIPTION OF PREFERRED EMBODIMENTS With reference to Figures 1 and 2, by means of compressed air from an air compressor 53 a suction plate 15 located at an extremity of a main unit 1 of the labelling robot, a position corresponding to the head, can perform the reciprocal motions of vertical ascension and descent (Y direction) horizontal advance and retreat (X direction) and turning motion through 90° (Z direction). More specifically, with respect to the reciprocal Y direction vertical action, the supply of air to the air cylinder 2 via the intake 2a and the removal of air therefrom via outlet 2b raises and lowers the main unit 1 in unison with the action of the piston rod 3. Provided parallel with the rod 3 is a pair of guide rods 5 which are held by a base 4a and an upper support portion 4b, stabilizing the vertical motion of the main unit, and a centrally located vertical stroke adjustment member 6 is also provided. To provide compressed air to the air cylinder 2, a control signal is transmitted from the sequence controller 50 to the air control box 51, causing air to be sent from the air compressor 53 via the air passage A. With respect to the horizontal X direction reciprocal motion, this is the horizontal motion of an advance arm 10a which is connected to a piston rod 8, said motion being effected by air being provided to or removed from horizontal air cylinder 7 via air passage B, by means of, respectively, the intake 7a and outlet 7b thereof. The advance arm 10a is fixed to a pair of guide rods 11 which are slidably mounted in the main unit 1, and the head block 12 of a rotation air cylinder 13 is fixed to an end of the said guide rods 11. With respect to the Z direction motion of rotation, this turning motion through 90° about a shaft 14 is effected by air moving through air passage C into or out of the rotation air cylinder 13 by means of intake 13a or outlet 13b thereof. At the end of the rotation air cylinder 13, on piston rod 29, is provided a suction plate 15 which is made of light aluminum, and which corresponds to the head of the robot. The intake 15a and outlet 15b of the suction plate 15 are connected, via a suction passage, to the air control box 51 in which is located a vacuum switch 52. The suction plate 15 is provided with air for suction, for the label sucking action, the air from a compressor 53 being converted by a solenoid valve (not shown). The suction plate 15 will now be described in further detail, with reference to Figures 6 to 10. For large labels the large suction plate of Figure 6 is employed, and for normal sized labels the normal type suction plate shown in Figure 7 is employed. Both suction plates are basically similar in construction, the differences being the area of the suction surface and the number of suction elements, described hereinbelow, each is provided with. Screwed into the suction surface of the suction plate 15 is a plurality of suction elements 16 provided with suction pads 20. As shown in Figure 8, each suction element 16 is provided with a threaded portion 17 at the lower part of the main body, a suction hole 18 which passes through the middle of the threaded portion 17 and the main body, and a hole 19 in the shape of a flat ring, and into which fits the boss 21b of the suction pad 20, which is formed of soft rubber material. The suction portion 21a of the suction pad 20 is in the shape of a cone and is thin and resilient. As can be seen in Figures 9A and 9B, each suction element 16 with its suction pad 20 fits into an engaging hole 22a, provided with a threaded portion 22b, which is formed in the surface of the suction plate 15. Attached to one side of the suction plate 15 is an air pipe 24 which is connected to the air compressor 53 and, via air passage 24a, to the engaging hole 22a. The cone-shaped end of the suction pad 20 of each suction element 16 is slightly proud of the suction surface of the suction plate 15 (see Figure 10). The suction plate 15 is affixed by means of threaded fasteners 25 (Figure 10) which engage in the threaded hole 23 provided on the reverse side of the plate (Figures 9A and 9B). The attachment of the suction plate 15 to the rotation air cylinder 13, and the internal construction, will now be explained with reference to Figure 10. In attaching the suction plate 15 by means of the threaded fasteners 25, a connecting plate 27 is disposed between the plate and a metal plate 26b attached to a shock absorbing member 26 formed of rubber material, said shock absorbing member 26 being attached to a support member 28. To provide good shock absorbency, the shock absorbing member 26 is provided at appropriate locations with hollow portions 26a. Attached to the center of support member 28 is a piston rod 29 provided with a spring 30; also attached to the support member 28 on one side of the rod 29 is a detector rod 34, and on the other side a guide rod 35. The end of the spring 30 of the rod 29 is held by a spring holder 31 which is resiliently maintained by an auxiliary spring 32. The auxiliary spring 32 is housed in a sleeve 33 which is in contact with said spring 31, and is supported by a fastener 36 on the end of the piston rod 29. A leg portion 37 of the sleeve 33 is provided with a detector rod 34 duct 38. Where the end of the slidable rod 34 comes is a limit switch S-7 which can contact or separate from the end of the rod 34. This limit switch is connected to the sequence controller 50 by an electrical circuit g which is described below. The upper portion of the sleeve 33 is provided with a guide hole 39 for a guide rod 35, for smooth advance and retraction of the rod 29. As shown in Figures 1 and 11, a shock adjustment member 40 for adjusting the horizontal stroke of the labelling robot and easing the impact at the moment of contact with a labelling object 65 at the time of the label affixment is affixed to the retract arm 10b which is supported by the pair of guide rods 11 of the main unit 1. In further detail, with reference to Figure 11, affixed to the retract arm 10b is a cylinder 42 which houses a shock absorber 43 comprised of a spring. Provided at the rear end of the shock absorber 43 is a cylindrical threaded adjuster 41 and the front end is in contact with a piston rod 44. The piston rod 44 is attached at its front end to the advance arm 10a in opposition to a shock absorber rod 45 which is provided so as to be freely slidable in the main unit 1. Reverting to Figures 1 and 2, connected to sequence controller 50 are limit switches S-1 to S-7 disposed at the positional limits of the movement strokes of the labelling robot. Specifically, DOWN limit switch S-1 which defines the lower limit of movement of the main unit 1 is connected to the sequence controller 50 by circuit a, UP limit switch S-2 which defines the upper limit of movement is connected by circuit b, ADVANCE limit switch S-5 which defines the forward limit of movement of the advance arm 10a is connected by circuit e, RETRACT limit switch S-6 which defines the retraction limit of said arm 10a is connected by circuit f, ANGLE limit switch S-3 and STOP-TURNING limit switch S-4 which define respectively the upward and downward rotational limits of the rotation air cylinder 13 are connected by circuits c and d, respectively, and limit switch S-7, which is to provide confirmation of the label attachment to the suction plate 15 disposed at the front end of the rotation air cylinder 13, is connected by circuit g. The actions of sucking up labels and affixing same to an object by means of the labelling robot according to this invention will now be described with reference to Figures 1 to 4. Before that, however, is a description of the label used with the present invention, e.g. the label 62 illustrated by Figure 5, which is a composite label 60 consisting of said label 62 having a print side 62a and on the reverse side an adhesive surface 62b, which tacks onto a tape-shaped support 61. On the print side 62a of the label is printed by a printer or other such means, for example, a part number, or production number, destination, or other such indication that can be encoded in bar code form. The tape-shaped support 61 is moved to position the printed labels 62 on a label stand 63 (see Figures 1 and 2). The said printer (not shown) is connected to the sequence controller 50, and after completion of the printing outputs a PRINTING FINISHED signal to the sequence controller. The sequence controller then outputs a signal to the air control box 51 to start the air compressor 53. The compressed air from the air compressor 53 is fed to the labelling robot to effect the various vertical, horizontal and turning functions, and in the case of the suction plate, is converted by means of the solenoid valve into suction force. The following stroke adjustments are completed prior to the commencement of the various actions of the robot. Specifically, with reference to Figure 2, adjustments are carried out to match the vertical strokes to the height of the object 65 to be labelled, which is brought on a conveyor 64 provided in front of the labelling robot, and to match the horizontal strokes to the distance from the robot to the object 65. Adjustment of the height of the vertical stroke is done by adjusting stroke adjustment member 6 to set the height at which the UP limit switch S-2 operates, and adjustment of the horizontal forward stroke is by adjusting the shock adjustment member 40 to set the distance at which the ADVANCE limit switch S-6 operates. adjustment is already completed of the DOWN limit switch S-1 for the stroke down to the stand 63 on which the label is located. With reference to Figures 1, 3 and 4, as compressed air from the air compressor 53 is supplied via the air control box 51 and air passage A to the vertical air cylinder 2, the main unit 1 commences its downstroke. With this downward movement of the main unit 1, the advance arm 10a, rotation air cylinder 13 and the suction plate 15 come down toward the label 62 which is readied on the label stand 63. When the DOWN limit switch functions, the suction circuit D comes ON, and the sucking action of the suction plate commences, causing the label 62 to be sucked up by the suction force of the suction pads 20. The suction pads 20 deform with the action of sucking up the label, causing the pads to become flush with the surface of the suction plate 15. The action of the vertical air cylinder 2 raises the suction plate 15 with the label in sucking attachment thereto, switching on the UP limit switch S-2, which is followed by confirmation that a label is being held by the suction plate 15, said confirmation being carried out by a vacuum switch 52 which detects the degree of vacuum of the suction plate 15. If the confirmation is negative and remains negative even after several retries, a warning is issued. In such cases of negative confirmation of label attachment, the system retrace extends back to the step preceding the downward stroke, i. e. the end of printing. If label pickup by the suction plate 15 is normal the system proceeds to the next stroke, which is the stroke whereby the suction plate 15 is raised to the necessary height. Next, compressed air is supplied to the rotation air cylinder 13, rotating the suction plate 15 by 90° counterclockwise, the point at which the limit switch S-3 comes on. This rotation therefore brings the suction plate 15 to the horizontal, facing the object 65 to be labeled. Next, with reference to Figures 2 to 4, when a sensor (not shown) provided on the side of the conveyor 64 reaches the specified location of the object 65 it communicates this by outputting an object detection signal to the sequence controller 50. Preferably the circuitry is such that this signal is transmitted to the printer to start the printing of the next labels. The above object detection is followed by the commencement of the forward stroke of the suction plate 15. Specifically, as compressed air is supplied to the horizontal air cylinder 7 the advance arm 10a, retract arm 10b and the suction plate 15 at the front end of the rotation air cylinder 13 with the label 62 in sucking attachment thereto advances horizontally towards the object 65. With the printed side 62a of the label 62 in contact with the suction pads 20 of the suction plate 15, the adhesive side 62b of the label 62 is positioned at the front and comes into contact with the object 65 to thereby stick the label 62 in place. Roughly simultaneously with this the ADVANCE limit switch S-6 and the label attachment confirmation limit switch S-7 switch ON. With regard particularly to limit switch S-7, the reaction as the suction plate 15 comes into contact with the object 65 is borne by the spring 30 provided on the rod 29, and the compression of the spring causes a slight retraction of the detector rod 34, the tip of the rod 34 triggering the limit switch S-7. This is shown, with details of the parts involved, in Figure 10. On the suction plate 15 side the impact energy generated at the moment of attachment of the label is absorbed by the shock absorbing material 26 with its hollow portions 26a, provided at the back of the suction plate, and by the spring 30 and auxiliary spring 32. The impact energy is also absorbed by the shock adjustment member 40, as the contact energy of the piston rod 44 on the shock absorber rod 45 of the advance arm 10a is transmitted to and absorbed by the shock absorber at the end of said rod (Figure 11). If at this time a negative confirmation of label attachment is issued, the sequence of operations is repeated, in the same way as when the suction plate fails to suck up a label, and if confirmation is still negative a warning is issued. In such cases of negative confirmation of label attachment, the system retrace extends back to the step preceding the horizontal forward motion, i. e. to object detection. If confirmation of label attachment is positive (ON), the sucking action by the suction plate 15 is stopped and compressed air is supplied to the horizontal air cylinder 7, horizontally retracting the suction plate 15 until the RETRACT limit switch S-5 is triggered ON. Next, compressed air is supplied to the rotation air cylinder 13 to rotate the suction plate 15 through 90° clockwise. With this rotation the suction plate 15 faces downwards, reverting to the restart condition, and with the STOP (angle of dip) limit switch being triggered ON, the system returns to the original position. The above sequence of actions comprise one system cycle from picking up a printed label by suction to the sticking of the label on the required object. What is printed on the label as well as the size and type of the label, and the object, may be varied as required. Thus, the labelling robot system according to the present invention comprising limit switches which regulate the strokes of the vertical, horizontal and rotation air cylinders, said limit switches being connected to a sequence controller, and air circuits for these strokes and for the sucking action connected to an air control box which is also connected to the sequence contoller, provides system efficiency from the sucking up of the label through to the adhesive attachment of the label, one system cycle comprising lowering of the head (i. e. the suction plate), sucking up of a label, the raising and turning to the horizontal of the head, advancing the head to the object to be labelled and the sticking of the label thereon, the cessation of the sucking action, horizontal retraction, and rotation downwards. It should be noted that the shock absorber rod (45) serves as a contact portion and for that reason said member (45) may be referred to as "a contact portion". According to the present invention there is provided a shock absorbing device comprising first and second shock absorbing memebers. The first absorbing member comprises the afore-mentioned cylinder (42) located at the afore-mentioned retract arm (10b) of guide rod (11) and in particular, said first absorbing member consists of the combination of the shock adjustment member (40) having a shock absorber (43) and a piston rod (44) housed in said cylinder with the contact portion (45) of the fixed main unit. The above explained first shock absorbing member is best shown in figures 1, 2 and 11. The second shock absorbing member is best shown in figure 10 and comprises three members, namely the afore-mentioned rubber made shock absorbing member (26) attached to the aforementioned suction plate (15), the spring (30) wound on the piston rod (29) attached to the absorbing member (26) as well as an auxiliary spring (32). Typically, the inventive shock absorbing device provides at the time of label application for a double action absorbing function. As indicated above, the first absorbing member has an end of piston rod (44) biased flexibly by the shock absorber (43) which is housed in the cylinder (42) and is in contact with the contacting portion (45) of the main unit 1. The compression action by said shock absorber (43) allows for the impact to be absorbed and provides for the required contact pressure (impact pressure) of the moveable suction plate (15) on to the object (65) to slow down. By means of the second absorbing member, the reaction of the contact energy (impact energy) is absorbed by the combination of shock absorbing member (26), spring (30), and auxiliary spring (32). The effect of the present invention is as follows: In the shock absorbing device for the inventive labelling robot, the first absorbing member is provided with a shock adjustment member having the piston rod (44) at the other end of the guide rod (11) which moves with the movement of the suction plate (15) with the other end of the piston rod (44) being in contact (if required) with the contacting portion (45) of the main unit (1). The second absorbing member is a combination of three members, i.e. the rubber made shock absorbing member (26), the spring (30) wound on the piston rod (29) attached to the rubber made shock absorbing member, and the auxiliary spring (32), each of the three members being connected to one another. When the suction plate to which a label is adhered comes into contact with the object in order to apply the label thereupon, the generated contact energy (impact energy) can be absorbed by the second absorbing member consisting of the three above-indicated members.

Claims: A labelling robot of the type comprising a suction plate (15) located on a main unit (1) for picking up and applying an adhesive label (62) to an object (65), characterised by first and second shock absorbing members for absorbing the impact energy generated at the time of applicating a label (62) adhered to said suction plate (15) on to said object (65), said first absorbing member comprising a cylinder (42) located at one end of a guide rod (11), at the other end of which said suction plate (15) is provided, said guide rod (11) being movable with the movement of said suction plate (15) and further comprising a shock adjustment member (40) having a shock absorber (43) as well as a piston rod (44) housed in said cylinder (42), said second shock absorbing member comprising three members, namely, a flexible shock absorbing member (26) attached to said suction plate (15), a spring (30) wound on a piston rod (29) attached to said flexible shock absorbing member (26) as well as an auxiliary spring (32); the end of the piston rod (44) housed in said cylinder (42) being in contact with a contact portion (45) of the main unit (1) at the time that the suction plate (15) is impacting on to the object (65).

Inventors: ABE NORIO, MATUDA YASUHIKO, ABE, NORIO, MATUDA, YASUHIKO
Applicants: SATO KK, KABUSHIKI KAISHA SATO
Application year: 1990
Main classification: B65C9
IPC codes: B65C9, B65C1, B65H37, B65H41