EP0458854B1

EP0458854B1 - Table tennis robot

Info

Publication number: EP0458854B1
Application number: EP90903439A
Authority: EP
Inventors: Kristen Jarle Blindheim
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-02-20
Filing date: 1990-02-16
Publication date: 1995-02-15
Anticipated expiration: 2010-02-16
Also published as: NO890702D0; DE69017011D1; NO167441C; NO890702L; WO1990009216A1; EP0458854A1; NO167441B; ATE118367T1

Abstract

A table tennis robot sends a ball towards a player, so as to simulate a realistic situation in a game, where the device comprises a firing unit, a receiving unit and a collection unit. A damping plate (1) is located on the table-tennis table, on the opposite side of the table from the player. The damping plate (1) slows and controls balls from the player. A trigger mechanism ensures that the player receives a return ball when the player hits a ball correctly. The device may embody more than one firing unit with associated trigger mechanisms, so that return balls come from the same area that the player has hit the ball to.

Description

The invention concerns a table tennis robot assembly that serves, collects and returns balls to a player, either automatically or as a result of an external impulse so as to simulate a realistic situation in a game.
Various types of training appliances are known in sport. Some of these simulate real competitive play, in other words an opponent. In the sport of table tennis, there are machines that automatically "feed" balls to a player.
US Patent 4 002 336 describes a table tennis robot comprising a ball firing unit, a ball receiving unit and a ball collection unit which includes a suction unit that transports balls from the receiving unit towards the firing unit. This robot sends table tennis balls that a player is to return, so that the balls are collected by a large net, which constitutes the receiving unit, behind the table. The balls that are returned to the player all come from approximately the same point, notwithstanding pivoted adjustment of the angle of firing of the balls in a vertical plane, and swinging of the firing gun in horizontal plane, so this device does not give varied enough training. Furthermore, the robot does not follow the rules of table tennis, since a ball is returned irrespective of where the player hits the previous ball. There is no known table tennis robot that provides what can be characterised as play. A further problem with known robots is that they are often too noisy, and usually are stressing for the player because the tempo of play is too quick.
The main object of the present invention is to devise a table tennis robot assembly that gives a training situation that really provides a game.
Another objective of the present invention is to devise a table tennis robot that returns varied balls.
A further objective of the present invention is to devise a table tennis robot that returns balls from different positions as a response to shots from the player.
A further objective of the present invention is to devise a table tennis robot that returns balls after a serve from the player, or after a player has pressed an impulse switch.
A further objective of the present invention is to devise a table tennis robot that returns balls only after the player has hit the other side of the table.
A further objective of the present invention is to devise a table tennis robot that is almost silent.
A further objective of the present invention is to devise a table tennis robot that does not return more balls than the number the player returns.
The main object of the present invention is met by a device which has the features set forth in the characterising part of Claim 1. Other advantageous features of the invention are referred to in the subsidiary claims.
Preferred embodiments of the invention will now be described in more detail with reference to the accompanying drawings, in which

Fig. 1 is a schematic side view of a part of a table tennis table to which a version of the robot assembly of the present invention has been fitted;
Fig. 2 is a front view of the configuration of Fig. 1;
Fig. 3 shows, in detail, the collection system of the embodiment shown in Fig. 1;
Fig. 4 is an enlarged side view of the feed mechanism taken from the configuration shown in Fig. 3;
Fig. 5 is a front view of the feed mechanism shown in Fig. 4;
Fig. 6 is a schematic side view of a table tennis table to which a second embodiment of the robot assembly of the present invention has been fitted; and
Fig. 7 is a front view of the embodiment shown in Fig. 6

Reference is first made to Figs. 1 and 2 where a damping coating or a damping plate 1 covers the half of the table facing (i.e. opposite) the player. At the edge of the table and the aforesaid plate there is a vertical damping plate 3, fitted in profile 12. This plate 3 is to dampen top-spin balls, and help prevent a missed shot releasing the mechanism. There are guide plates 15 along each of the sides. Immediately behind the table, at a distance that is at least the diameter of a ball, there are plates 2 that are connected to vertical pendulum frames 8. The pendulum frames 8 are hung from a mount 7 around which they can swing. The number of plates 2 with connected pendulum frames 8 can be varied. There are four in the example shown here. Each of the pendulum frames 8 is connected to its own microswitch 5, which is located above the axis of movement around the mount point 7 where the microswitches are additionally mounted on a top cover 11 of the collection unit of the robot.
When a player hits a ball, the plate 1 will dampen the ball and control its bounce. The ball will then travel horizontally towards the plate 2. The force of the ball striking the plate 2 causes the pendulum plate 8 to move around the axis of its mount 7. The microswitch 5 is activated by this movement through an adjustable screw 6. The microswitch 5 is connected to an automatic launcher, with feed, generally-termed 26 (Figs. 4-5) and a per se known firing unit. There are openings 17 between the pendulum frames 8 where the firing unit has space to shoot balls towards the player. U-shaped profiles are fitted between each of these. The firing unit is fitted on tracks 9 to provide a means of regulating the lateral direction. This firing unit provides a controlled return of the next ball. There should be at least two firing units so that balls can be returned from the correct side. There may also be as many firing units as receiver units (comprising plate 2, pendulum plate 8, with adjustable screw 6 and microswitch 5). If the player does not manage to hit the ball onto the opposing half of the table, there is no return ball from the robot as the pendulum plate 8 is not touched. Below the receiver plate 2 there is an open channel 4, which has a slope towards each side with its highest point in the middle. When balls fall into this, they will roll to the outside point where they are sucked into a container by a fan arrangement (Fig. 3). An under plate 10 returns balls to the player when there is a shot that does not land on the table. These balls also fall into the channel 4. Apart from the edge guide 15 and the plate 1, the collection system is mounted on a frame support 14 with wheels 13 so that it can be quickly fixed to the table.
In addition to, possibly instead of the pendulum plate 8, photo-electric cells can be used to register when the balls come and where they hit. This is a particular advantage with slow balls (slice shots), as the impetus of the ball may then be too slow to make the pendulum frames move. Such photo-electric cells can be positioned just above the surface of the table.
Fig. 3 shows the collection system in accordance with the present invention. The open channel 4 is connected at its end to a tube 21, into which the balls are sucked. The tube 21 has an internal diameter which is fairly close to the outer diameters of the balls. This ensure good suction. The tube 21 is connected at its other end to a suction chamber 16, which contains a motor 27, a fan 29 and a cap 28, all of known design. The motor 27 for the fan 29 can be regulated and used to control the speed of the game. A coiled spring 23 is located inside the suction chamber 16 where the tube 21 ends. The coiled spring 23 guides the balls through the chamber 16 and has a diameter that is a little larger than tube 21. The coiled spring ends in a tube connection 24 which guides the balls to another coiled spring 30. A ball in the space between chamber 16 and the tube connection 24 will act as a valve until the next ball comes. From spring 3, the balls go into a feed unit 26 through a tube connection 25 which is flexibly connected to chamber 16. The coiled spring 3 and the tube connection 25 mean that the feed unit 26 can be placed in different positions and at different angles.
Figs. 4 and 5 show the feed unit 26 in detail. This consists of a restraining spring 33, that keeps balls in place until an impulse on a microswitch 5 gives the message that a balls is to be fired. This impulse goes to a propulsion mechanism 31 and works by a spring piston, or similar 32, striking the ball with enough force to release it from the restraining spring 33, so that the ball is fired. The propulsion mechanism 31 can be an electromagnet (piston or motor), air cylinder, or be another known system that is not part of the invention. After the propulsion mechanism 31, a non-illustrated firing mechanism of known design, can fire the balls towards the player.
Fig. 6 shows a simple playing machine that is designed along the same damping plate principle as shown in Fig. 1. The damping plate 1 is identical, and guide plates 15 are also used. The receiver plate 2, which is also a damping plate, has no fixing frame, but is attached to a mount 12 which also serves as a strut between the support 14 and the wheels 13. A cover 11 retains the receiver plate 2. Reference is also made to Fig. 7 where the collection channel 4 has a slope to one side. The player can adjust this slope to the side he/she wishes to get the return balls from. A frame 10 can be fitted to either side. After the feed mechanism, the ball goes through a tube connection 24 to a chute 34 and rolls towards the player who gets enough time to prepare a shot. The chute 34 can be adjusted in height as well as sideways. This design is particularly useful to train beginners in hitting straight returns. This is done by allowing balls from the chute 34 be hit to plate 1, and damped between plates 1 and 2 and fall down into the open chute 4. Then the balls will roll along to one side and be sucked up through the riser tube 21 by the motor 27 and the fan 29. The suction chamber 16 can be designed as in Fig. 3, but a simpler design is preferred. The tube 21 is connected obliquely to the chamber 16 and in the chamber there are guide springs for the balls. At the bottom of the chamber 16, there is a tube connection 24 where a ball will hang suspended by the suction from fan 29. When the next ball comes, this will fall on the ball that is in connection 24, and force this to roll down chute 34, and stop in connection 24 itself. The system has two to three balls in circulation, depending on the tempo that is required. In addition, this design has a return tube that can be used when a player wants training in serving. In this case, the fan 29 is stopped and there is an opening from the channel 4 to a further chute 36, located below the table. This means that the player does not need to pick up balls, but gets them returned to the playing position.

Claims

A table tennis robot assembly of a type that automatically, or as a result of an external impulse, sends a ball towards a player so as to simulate a realistic situation in a game, comprising a ball firing or supply unit (26), a ball receiving unit (2,3) and a ball collection unit (4,16, 21-30) which includes a suction unit (16) that transports balls from the receiving unit towards the firing or supply unit (26) characterised in that a damping plate or coating (1) is provided which, in use, is located or applied on a table-tennis table, on the opposite side of the table from the player, and in that the or each receiving unit includes a receiving plate (2), for impact of balls thereagainst, disposed in an approximately vertical position behind the edge of the table.
An assembly as claimed in Claim 1 characterised in that below and behind the half of the table to which the receiver unit (2,3) is attached there is a sloping channel (4) whereby the balls are collected for transport by the suction unit (16).
A assembly as claimed in Claim 2 wherein the suction unit comprises a fan (29) and a motor (27) that create a pressure reduction in a chamber (16), and a tube (21) that is connected to the channel (4) at one end, and the aforesaid chamber (16) at the other end and which has an internal diameter substantially equal to the outer diameter of a ball, characterised in that the suction unit also comprises an initial spring (23) extending through the chamber (16) from the tube (21) to a first tube connection (24) which is flexibly attached to the chamber (16), and which is also attached to a ball feed unit (26) by means of a second spring (3) and a second connection (25).
An assembly as claimed in any preceding claim wherein the or each receiving unit (2,3) also includes a rotating pendulum frame (8), which is connected to a trigger mechanism (5) for the feed unit (26).
An assembly as claimed in Claim 4 wherein the trigger mechanism comprises a microswitch (5) that is released by means of an adjustable screw (6) through the movement of the pendulum frame (8).
An assembly as claimed in any of Claims 1 to 4 incorporating a trigger mechanism for the feed unit constituted by a photo-electric cell that registers that balls arrive and where they arrive.
An assembly as claimed in any preceding claim which comprises at least two firing units so that balls can be returned from the region of the table where they land.
An assembly as claimed in any preceding claim wherein an additional damping plate (3) is located in the front of the receiving plate (2).
An assembly as claimed in any preceding claim wherein the ball feed unit (26) comprises a coiled spring (33) located so as to hold balls in place and a propulsion mechanism (31).
An assembly as claimed in Claim 1 or 2 having a ball supply unit comprising a chute (34) that is flexibly connected at its upper end, close to the suction unit and inclines downwards towards the players half of the table.
An assembly as claimed in Claim 10 wherein the chute (34) has a height adjustment device (35).
An assembly as claimed in Claim 1 or 10 further comprising an additional chute (36) which is disposed so that it inclines in the longitudinal direction of the table with the highest end of the chute (36) being connected to channel (4) and lowest end being in the vicinity of the player, said chute (36) being operative when the suction unit is not in use.