The present invention is directed to an apparatus used to pick up tennis balls from the ground. Specifically, the apparatus is a push cart that includes a pick-up assembly mounted on it to easily allow a player/coach/instructor to collect and pick up loose tennis balls from the ground.
As any tennis player knows, it can be a nuisance to bend over and pick up stray tennis balls from a court surface or surrounding area. This is especially true for players, coaches and instructors who use a large number of balls with one or more players during a practice session. Often, dozens of balls will be lying on the court as a basket of balls is used to practice repetitive strokes or shots.
It is possible to pick up the balls manually by hand or by using a basket having a spaced-apart wire bottom adapted to lift the balls off the ground if pressure is pushed down on the basket. Additionally, there is a mechanical cart that is known to lift the balls off the court surface, but it is easily jammed if there are too many balls.
Accordingly, it is an object of the present invention to overcome the foregoing drawbacks and provide a pick-up assembly that can easily collect multiple balls lying on a court surface.
The ball pick-up device described herein includes a high-speed, spinning drum and a spring-biased drum rail. Each of these features alone and, in one example, in combination makes the ball pick-up device more efficient and effective. Specifically, the high-speed drum enables the rapid pick up and collection of the balls. The spring-biased drum rail reduces or eliminates the jamming of the pick-up device during use, especially when collecting a large number of balls on the ground.
In operation, the ball pick-up device rolls over a tennis ball or balls on a court or flat surface. A spinning drum spins in the same direction as the wheels on the cart. It is mounted on the cart so that the bottom of the spinning drum is above the surface at a height of about equal to the diameter of a tennis ball. The leading edge of the drum rail then contacts the ball and lifts the ball into contact with the spinning drum. The ball is then drawn by rotation of the drum and friction between the ball and the curved surface of the drum rail up and around the drum where the ball is then dispensed and falls into a ball basket.
Existing commercial collection devices employ a drum connected to and that rotates at a 1:1 speed of the cart wheels of those devices. Also, the drum rail is fixed and immovable relative to the rotating drum. These prior devices are slow, because the speed of the drum is limited by the speed of the cart wheels. Since the cart wheels are generally large circumference, typically more than about eight or ten inches, the drum rotates slowly. These prior devices will also jam easily when multiple balls are being picked up. It is believed that the balls become wedged between the drum and the rail when they rub up next to each other as they are being rotated around between the drum and rail.
By driving the drum with a pulley system, or alternatively a gear or sprocket system, the drum described herein rotates substantially faster than the wheels of the cart. Also, the spring mount of the drum rail allows some flex in the rail so that the balls that are being picked up have space to become unbound if many balls are being picked up together and they otherwise press against each other.
We turn now to an example of a ball pick-up device as illustrated in the attached drawings.
All of the
Referring first to
The base portion 50 of the cart 10 includes four wheels. The front wheels 57 are swivel wheels. This allows free steering of the device. The rear wheels 54 and 55 are fixed rotation wheels. In other words, they rotate freely, but they only rotate around the single axis 56 by which they are attached to the base portion 50. Rear wheel 55 also has a pulley wheel 75 mounted on the same axis 56. A pulley configuration could likewise be mounted on wheel 54. It does not functionally matter which side the pulley assembly is mounted on the base 50 of the device 10. The common axis 56 means that the wheel 55 and the rear pulley wheel 75 will rotate on a 1:1 basis together. The base portion 50 includes as its sides a pair of sturdy side brackets 52 onto which all of the wheels 54, 55 and 57 are mounted. The bracket 52 further has a second pulley wheel 80 rotatably mounted to it. This second pulley wheel 80 is connected to a spinning drum 65 mounted horizontally across the base portion 50. The forward pulley wheel 80 is smaller in circumference than the pulley wheel 75. A belt 85 is operatively mounted to and within the pulleys 75 and 80. Accordingly, when the device 10 is moved along a surface, the rotation of the wheel 55 causes the rotation of the pulley wheel 75 which, through the belt 85, causes the forward pulley wheel 80 to rotate in the same direction as the wheel 55. This forward pulley wheel 80 is connected to the drum 65. Accordingly, the movement of the device 10 causes the rotation of the drum 65. It is preferred in one example that a belt tensioner bracket (not shown) is mounted on the side support bracket 52. The belt tensioner includes a nylon roller and allows a user to adjust the tension on the belt 85 to create some tension and enable or improve the drive of the drum pulley wheel 80 by the wheel pulley 75.
Also mounted across the base portion 50 and between the support side brackets 52 there is a drum rail 70. The drum rail 70 is a rigid curved sheet that tracks a circumference that corresponds to and is spaced evenly apart from the circumference of the drum 65. The drum rail 70 is slidably connected to the side brackets 52 by way of pins 73 slidably mounted in the slots 53 in the side brackets. The drum rail 70 is allowed to move back and forth in the horizontal direction within slots 53.
The side support brackets 52 further include notches 92 that are adapted to receive the pins 32 of the ball basket 30. The side wall brackets 52 further include guide arms 59 that cast a wide swath when collecting loose balls 34 on a surface as well as protect and deflect balls from being run over by the rear wheels 55 in operation.
Turning to
In the forgoing example, the pulleys 75 and 80 are shown as a means of speeding the rotation of the drum 65. Alternatively, gears could be engineered to interact and obtain the faster rotation of the drum. A gear could be mounted and rotate around the axis on which the rear wheels of the device move. A second, smaller gear could be mounted around the axis of the drum to increase the rotation of the drum. Additionally, a chain and sprocket assembly could be used. Instead of pulley wheels 75 and 80, a large and small sprocket could be substituted and a chain looped around those sprockets to pull or drive the drum 65.
Also, the drawings illustrate specifically the use of springs 74 that bias the drum rail 70 to be forward rest position. Other types of spring materials could be used including rubber mounts or leaf springs or any other elastic material that would bias the drum rail to the forward and rest position but allow movement backwards.
In one example of a collection device, the rear wheels are ten inches in diameter. The rear pulley wheel has a diameter of 5.5 inches. The forward pulley wheel has a diameter of 3 inches. The rotating drum has a diameter of 8 inches and is 20 inches across the width of the cart. The drum has a smooth aluminum surface. The drum rail is a curved sheet of ⅛ inch thick aluminum having a circular curvature with an inside radius of 6.5 inches. The inside surface of the drum rail is smooth aluminum.
Of course there are variations to the structure that can be engineered accordingly to the teachings herein. The foregoing is merely one example of an effective device.
Other embodiments of the present invention will be apparent to those skilled in the art from consideration of the specification. It is intended that the specification and Figures be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
Number | Name | Date | Kind |
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4116192 | Scott | Sep 1978 | A |
4735544 | Stotts | Apr 1988 | A |
5301991 | Chen et al. | Apr 1994 | A |
Entry |
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“The Playmate Mower”, printout from website: http://www.playmatetennis.com/mower.htm, Oct. 1, 2011, and accompanying pictures (8 pages). |
Number | Date | Country | |
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20130064631 A1 | Mar 2013 | US |