Abstract: In a tennis racket having a racket frame composed of a fiber reinforced resin, the moment of inertia Ic of the tennis racket in a center direction thereof is set to not less than 13000 g·cm2 nor more than 17000 g·cm2, the moment of inertia Ig around a center of gravity thereof is set to not less than 80000 g·cm2 nor more than 200000 g·cm2, and the moments of inertia Ic and Ig are so set as to satisfy a relationship expressed by [30×(Ic)?(Ig)]/10000?31.

Abstract: A board game is provided and includes a game board having a planar playing surface and a pair of goals, one goal at each of the two opposite ends of the game board. The board game also has a pair of centrally facing ramps, one ramp at each of the two opposite ends of the game board. A target ball for positioning on the planar playing surface is provided and a plurality of projectile balls for rolling down the ramp surfaces and onto the planar playing surface are also provided. The board game also has a ball retrieval structure that includes a plurality of openings spaced along the game board that are sized to permit only the projectile balls to pass through. The ball retrieval structure is in communication with the goals such that when the target ball passes through one of the goals it falls into the ball retrieval structure.

Abstract: An improved golf training aid for right handed or left handed golfers that conditions the golfer through repetition and muscle memory to hit straight shots, controlled fade shots in varying degrees, and controlled draw shots in varying degrees without the need to use different golf swings for each shot or a different grip for each shot. The target arrow (12) is aimed at a chosen target and held into place by means of spikes (16). The invention aligns the golfers feet correctly for each shot by means of a body alignment shaft (60) and positions the golf ball correctly in relation to the golfers stance by means of a heel alignment block (50). The distance the golfers feet are from the ball is set by moving the heel alignment block (50) and the body alignment shaft (60) assembly either up or down the shot selection indicator shaft (40).

Abstract: A game racquet includes a head portion and a pair of removable handle portions. The head portion is adapted to support racquet strings and includes a pair of side portions which curve downwardly and inwardly at the bottom of the head. Each handle portion includes a substantially straight bottom portion and a curved top portion which is frictionally engaged with, and removable from, one of the side portions of the hoop. Dampening or resilient material is positioned between the frictionally engaged portions of the side portions and the handle portions.

Abstract: A play unit for moving at least one rolling element (14), having a considerably horizontal, changeable-inclination play surface (11) on which a rolling element (14) is guided and moves in dependence on the inclination of the play surface (11), the play unit being designed as a play table, of which the play surface (11) is mounted on a base (B) via a bearing device (F).

Abstract: A tennis training device for aiding in tennis-swing training and warm-up exercises includes a tennis racket or like-shaped frame having handle and head portions spaced apart along a central axis, a central opening disposed between the frame portions, an axial shaft the opposite ends of which are removably mounted to the head and handle of the frame, and at least one weight member removably, slidably, securedly, mounted to the shaft at a preselected location in the central opening whereby to enable the player to adjust the center of gravity and weight balance of the frame. In a preferred embodiment, two temporary lockable interdigitating members and a locking member that engages the shaft to position the weight member at the preselected location define the weight member.

Abstract: A table game apparatus includes a playing field assembly which includes a ground portion and walls which project upward from edges of the ground portion. Width-extending walls and length-extending walls are arranged on the top side of the ground portion in a four-cornered rectangular array. A first ball launching assembly is located at a first corner of the four-cornered rectangular array. A second ball launching assembly located at a second corner of the four-cornered rectangular array. First and second pairs of flippers are located on the ground portion. First and second pairs of flipper control assemblies are provided for controlling the first and second pairs of flippers. The first and second pairs of flipper control assemblies are supported by the ground portion. A first goal area is located on the ground portion behind and between the first pair of flippers. A first ball retention region is located behind the first goal area.

Abstract: A balance member is formed of a plurality of substantially planar rigid trunk elements arranged in a vertical stack and alternately oriented orthogonally to each adjacent trunk element. Each planar trunk element further supports a pair of oppositely positioned substantially horizontal tier members. A chance device and a plurality of tokens are provided to complete the game apparatus. The game is played by operating the chance device at the initiation of each player's turn to designate a particular tier level upon the balance member which the player must place a token successfully without tipping the balance member during each turn. The balance member is supported by a base having a downwardly convex preferably spherical surface which allows the balance member to tip in response to imbalances of token distribution caused by player placement of tokens.

Abstract: A play feature for a pinball game features a multimode target with a variable trajectory ball ramp. The multimode target features a pair of distinct targets mounted upon the playfield of the pinball game in a rotating fashion. The multimode target may be rotated between positions whereby each of the distinct targets is exclusively accessible by the game ball thus providing the pinball game with more than one mode of play. A variable trajectory ball ramp is positioned upon the playfield and is curved and banked towards the multimode target. A pinball properly negotiating the ramp may strike the multimode target so as to increase the player's score. The multimode target may oscillate and the distinct targets may feature a number of sub-targets as well as oscillating barriers.

Abstract: A vibration proof device for strings or frame of a racket for sports in which it is possible to absorb vibration not only of the strings but also the frame without hindering operation, comprised of a block of rubber or plastic having a centrally located mushroom shaped vibrator integrally formed by punching or moulding, said block having a size that is substantially the same size as the width between strings and having longitudinal recesses in opposite sides for fitting between strings in use.

Abstract: A retention device for use with an object having a handle, such as a racquetball racquet, comprises a wrist ring for securing the device about a wrist of a person gripping the handle, an elastomeric connecting member, and a securing means remote from said ring for securing said device to a handle. In one preferred embodiment, the ring and connecting member are elastomeric loops linked together. Alternatively, the ring and connecting member may be a unitary piece formed of elastomeric material, and the securing means is in the form of a loop portion or other securing means at the remote end of the connecting member. The connecting loop or loop portion are preferably secured by a pin inside the butt of the racquet handle.

Abstract: A goaltender simulator system, which closely simulates shooting on a goal tended by a live goaltender, is provided. The system includes a digital video camera which tracks the trajectory of the object launched toward the goal. The continuous image data is filtered to enable a computer control to accurately determine the trajectory of the object as well as estimate its anticipated trajectory. Knowing the anticipated trajectory of the object, the computer control instructs motors to move the goaltender figure and/or its arms to the appropriate position to block the incoming object in an attempt to prevent it from entering the goal.

Abstract: A pinball machine is provided and includes a game cabinet having disposed therein a playfield movable between open, intermediate, and closed positions. A support assembly is used for maintaining the playfield within the cabinet. The support assembly includes a pair of cabinet brackets mounted one to each side of the cabinet where each of the brackets has a riding surface. A pair of wheels are mounted to the playfield and are provided to ride along the riding surface of a corresponding one of the cabinet brackets. A pair of support arms is further provided each having one end thereof pivotally attached to the cabinet and the other end thereof pivotally attached to the playfield wherein at least one of the support arms has pivotally attached thereto a prop arm which is engageable with the playfield when the playfield is disposed in the intermediate position.

Abstract: A ball game device is formed by an elongated generally upright open end ball receiving tube. In one embodiment the tube has a carom block adjacent its depending end for diverting a ball dropped into the tube in a predetermined lateral direction. In another embodiment the depending end portion of the tube is curved in a lateral ball diverting direction and is supported by a base.

Abstract: The play feature of the invention comprises a ball well and electromagnetic coil. A ball sensor is located near the well entrance to signal when a ball is detected. The electromagnet, disposed at the well entrance, attracts the ball from the playfield into the well where it is retained. To eject the ball, the magnet is reenergized and the ball is ejected form the well onto the playfield.

Abstract: A coniostomy tube intended for insertion through the front wall of the larynx between the bottom edge of the thyroid cartilage and the upper edge of the front part of the cricoid cartilage includes a pre-shaped curved tubular pipe having a substantially straight patient-end section, a pipe connector and an intermediate tube section which is curved through substantially 100.degree.. At least that part of the tube which extends through the opening between the thyroid cartilage and the cricoid cartilage has a substantially oval cross-sectional shape with the small axis of the ovality positioned in the curvature plane of the tube. This ovality is in the range of 1:1.2 to 1:1.35. The curved intermediate section of the tube preferably has essentially the same ovality and ovality orientation, and the tube may also have the same oval cross-sectional shape along the whole of its length. The outer pipe connector of the tube preferably forms an angle of 80.degree.

Abstract: A valve for regulators in self-contained underwater breathing apparatus includes a tubular plug (9) axially slidably accommodated in two sealingly separated adjacent chambers (6,7). Of these two chambers, the so-called pressure chamber (6) is connected with a pressurized gas source, and is provided with a seat (11) for cooperating with the matching edge (109) of the tubular plug (9), and the so-called compensation chamber (7) is formed with a hole or holes (107) connected with the ambient medium, and has the relative end portion of the tubular plug (9), which is in form of a flaring-out expansion head (209) connected with the valve outlet (12), sealingly guided therein. A helical spring (10) is arranged between the expansion head (209) and the opposite partition (8), dividing the two chambers from each other.

Abstract: A financial institution, such as a bank, issues numerous uniquely coded certificates to various individual entities in exchange for monetary value received. The holder of each certificate is entitled to receive a certain average rate of income from the monetary value represented by that certificate; which average rate of income would generally be proportional to prevailing interest rate as well as to the monetary value represented by the certificate. To avoid the relatively high transaction costs associated with periodic payments of a relatively modest income to the holder of each of numerous individual certificates, a statistical method is used. By way of this statistical method, a relatively few of the numerous uniquely coded certificates are randomly chosen at the end of each of a continuous sequence of time periods, and all the income attributable to all the issued certificates for the associated time period is then paid to the holders of the relatively few certificates chosen for that time period.