Abstract:
A teeter-totter base for training canines may be coupled to the middle of an elongated plank. The base has a pair of legs that can be rotated in order to change the height of the plank off of a ground surface.

Description:
FIELD OF THE INVENTION 
   The present invention relates to training equipment for canines and, more particularly, an adjustable base for a teeter-totter. 
   BACKGROUND OF THE INVENTION 
   Dog agility began as an exhibition sport in Great Britain and was imported into the United States in 1977. It was patterned after equestrian events and combines handler control, agility, and confidence. An agility ring is set up with a variety of obstacles. Obstacles include jumps, tunnels, a dog walk, a teeter-totter, an A-frame, and weave poles. The ring is generally square, about 100 feet×100 feet, and fenced off from the spectators. Dogs go through the ring on a leash with a handler (basic agility), or off leash with a guiding handler (advanced agility). They are judged by their ability to correctly negotiate the obstacles in a predetermined order. The dogs are judged primarily by the correctness by which they move on and off the obstacles and by which they stop and stay on command on other obstacles. The dogs are secondarily judged by their time in completing the obstacle course. This event requires significant training of both handler and dog. 
   The teeter-totter is an elongated plank that rotates about a pivot point located generally in the middle of the plank. In competition, the height of the pivot above the ground is based on the size of the dog. The plank is typically 8–14 inches wide and 10–14  feet in length. Contact zones, near each end of the plank, are typically 3–4 feet long. When a dog approaches the teeter-totter, one end of the plank, either the near end or the far end, is in contact with the ground. The dog must touch the near contact zone with at least one paw, traverse the plank, and then touch the far contact zone with at least one paw before proceeding to the next obstacle. As the dog traverse the obstacle, the plank rotates about the pivot point. 
     FIG. 1  is a side view of a plank  4  resting on a brick  6  in accordance with the prior art. Training of a dog  2  starts off by acquainting the dog  2  to a plank  4  resting on the ground. After the dog  2  masters touching the contact zones, the trainer may elevate the middle of the plank with a brick  6 , as shown in  FIG. 1 , to a height “H”. As the dog  2  gains more confidence, the trainer may stack additional bricks under the plank  4 . A drawback to stacking bricks is that the bricks may topple while the dog  2  is traversing the obstacle and make the dog afraid of the obstacle. 
   Therefore, there is a need for a teeter-totter in which the pivot height of the plank can be quickly changed while still providing a secure structure. 
   BRIEF SUMMARY OF THE INVENTION 
   Embodiments of the present invention provide an adjustable height teeter-totter. 
   Briefly described, in architecture, one embodiment, among others, can be implemented as follows. A teeter-totter having an elongated plank coupled to a base, having first and second legs rotatably coupled to a bracket. The first leg and the second leg are rotatable from a first position to a second position such that the height of the plank  from a ground surface is less when the first leg and the second leg are in the first position than when the first leg and the second leg are in the second position. 
   The present invention can also be viewed as providing a method of training a dog to traverse a teeter-totter. The method having the steps of: (1) placing a base secured to a bottom surface of an elongated plank in contact with a ground surface, the base allowing the elongated plank to rotate about the base; (2) allowing the dog to walk along the length of the plank with a center of the plank at a first height; (3) rotating a first leg coupled to the base until the first leg contacts a first stopper and rotating a second leg coupled to the base until the second leg contacts a second stopper; and (4) allowing the dog to walk along the length of the plank with the center of the plank at a second and greater height. 
   Other systems, methods, features, and advantages of the present invention will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Many aspects of the invention can be better understood with reference to the following drawings. Components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.  
       FIG. 1  is side view of a plank resting on a brick in accordance with the prior art. 
       FIG. 2  is a side view of a teeter-totter in accordance with a first exemplary embodiment of the invention. 
       FIG. 3  is an end view of the teeter-totter of  FIG. 2  in a “compact” position. 
       FIG. 4  is an end view of the teeter-totter of  FIG. 2  in an “extended” position. 
       FIG. 5  is side view of the teeter-totter of  FIG. 2  in a “compact” position. 
       FIG. 6  is side view of the teeter-totter of  FIG. 2  in an “extended” position. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 2  is a side view of a teeter-totter  100  in accordance with a first exemplary embodiment of the invention. The teeter-totter  100  may include an elongated plank  102 , for example a 2×12×12′, coupled to a base  104 . The base  104  may be in contact with, and coupled to, the middle of the plank  102  with a bolt  106  and cooperating nut  108  extending through an upper portion  132  of the base  104 . Alternatively, the base  104  may be coupled to the plank  102  with any mechanical fastener, for example, a screw, without departing from the present invention. 
   As shown in  FIGS. 2–4 , the base  104  may include an “L” bracket  110 , a first leg  112 , and a second leg  114 . The “L” bracket  110  and the legs  112 ,  114  may be made from aluminum or other materials. The legs  112 ,  114  may be hollow tube stock or, alternatively, may be solid. The first leg  112  may be rotatably coupled to a lower portion  130  of the “L” bracket  110  with a first fastener  116 , and the second leg  114  may be rotatably coupled to the lower portion  130  of the “L” bracket  110  with a second fastener   118 . The first leg  112  may be disposed on a first side of the lower portion  130  and the second leg  114  may be disposed on a second side of the lower portion  130 . Rotation of the first leg  112  may be restricted by a first stopper  120  and rotation of the second leg  114  may be restricted by a second stopper  122 . The stoppers  120 ,  122  may be mechanically coupled to the “L” bracket  110 , for example, by welding, soldering, or brazing. Alternatively, the stoppers may be pins inserted through the “L” bracket. 
   Alternatively, the legs  112 ,  114  may be hinged to the upper portion  132  of the “L” bracket  110 ; and the stopper may be mechanically coupled to the upper portion  132  without departing from the present invention. 
     FIGS. 3 and 5  show the teeter-totter  100  in a “compact” position, and  FIGS. 4 and 6  show the teeter-totter in an “extended” position. In the “compact” position, an edge  140  contacts the ground  142  and the plank rotates about the edge  140 . The edge  140  is spaced from the upper portion  132 . To convert the teeter-totter  100  from the “compact” position to the “extended” position, the user rotates the legs  112 ,  114  until the legs  112 ,  114  contact the stoppers  120 ,  122  respectively. The height from the ground  142  to the top surface of the middle of the plank  102  in the “compact” position is H1, and the height from the ground  142  to the top surface of the middle of the plank  102  in the “extended” position is H2. In the “extended” position, the legs  112 ,  114  contact the ground  142  and the plank rotates about the legs  112 ,  114 . 
   When a dog  2  approaches the teeter-totter  100 , one end of the elongated plank  102 , either the near end or the far end, is in contact with the ground. The dog  2  must touch the near contact zone with at least one paw, traverse the plank  102 , and then touch  the far contact zone with at least one paw before proceeding to the next obstacle. As the dog  2  traverses the teeter-totter  100 , the plank  102  rotates about the edge  140  in the “compact” position and the legs  112 ,  114  in the “extended” position. 
   During training, the user starts off with the teeter-totter  100  in the “compact” position, i.e., the middle of the plank  102  is at a height H1 from the ground  142 . After the dog  2  gains sufficient confidence, the user can rotate the legs  112 ,  114  into the “extended” position, i.e., the middle of the plank  102  is at a height H2 from the ground  142 . 
   It should be understood that, while the present invention has been described in detail herein, the invention can be embodied otherwise without departing from the principles thereof; and such other embodiments are meant to come within the scope of the present invention as defined in the following claims.