摘要:
A tennis racket is made lighter than conventional tennis rackets yet has a higher center of percussion and a higher frequency of vibration. The head of the racket is ovoid, and the widest part of the head is above the longitudinal midpoint of the head. The longitudinal strings are fan-shaped and diverge outwardly and upwardly from the bottom of the head.
摘要:
Ein Tennisschläger mit einer Schlagfläche und einem Handgriff weist in Kombination ein bespanntes Gesamtgewicht von weniger als 245 g, eine Gesamtlänge größer als 70 cm, eine frei-frei Eigenfrequenz im ersten Mode von höher als 210 Hz, einen Schwerpunkt von mehr als 41 cm und einen dynamischen Schwerpunkt von mehr als 50 cm, gemessen vom Griffende, auf.
摘要:
A tennis racket of oval overall shape is characterized in that the face comprises five regions. The geometric centre (M), the hilting centre (P) and three transverse strings are located in a central region (A), and three transverse strings the mean length of which is greater than that of the region (A) are located in each of two regions (B and C). The area in which the elasticity is substantially unifrom is thereby increased.
摘要:
The stiffness of a tennis racket is adjusted so that the first mode of bending of the racket under free-free constraint conditions is between 170 Hz and 250 Hz preferably between 200 Hz and 210 Hz. The second mode of bending under clamped-free constraint conditions is between 215 Hz and 315 Hz and preferably between 230 Hz and 265 Hz.
摘要:
The improved racquet (1) has a strung surface (11) which is larger in area than the strung surface of a conventional racquet, and in which the strung area (11) is both larger in length and width than the strung area of a conventional racquet. However, the overall weight and balance of a conventional racquetball racquet which have proven necessary for good playing characteristics for all such racquets have been maintained. The racquet (1) has synergistically combined the weight of the racquet, the stiffness of the frame (3), and the response characteristics to create a racquet of sufficient durability with a larger "sweet spot" to facilitate the palying of the sport and to increase the level of skill, particularly of the novice and intermediate players. The racquet (1) has an overall length of 18 ½ inches to 14 3 f 4 inches, a weight of 220 grams to 270 grams, and a center of gravity at a location within a range of ¾ inch toward the handle (3) and ½inch toward the head (2) as measured from the longitudinal center point of the racquet.
摘要:
A racquet includes polyester, monofilament racquet string and a frame extending along a longitudinal axis and including a head portion coupled to a handle portion. The head portion includes a hoop having inner and outer peripheral walls. The hoop defines a head size having maximum longitudinal and transverse dimensions, a , and, b , respectively. The dimension a is at least 1.2 times the dimension b . The inner peripheral wall includes string holes. The string has a diameter within the range of 1.10 to 1.55 millimeters. The string forms a string bed of interlaced main and cross string segments. Each of the cross segments transversely extends from one of the string holes to another, and each of the main segments longitudinally extends from one of the string holes to another. The string bed has at least one more main segment than cross segment, At least one of the main segments contacting the tennis ball exhibits a snap back velocity of at least 1 meter per second.
摘要:
A high specific-gravity EPDM composition consisting of a mixture of EPDM containing diene at less than 4.5 wt % and ethylene at not less than 58 wt % nor more than 80 wt % and having a Mooney viscosity ML 1+4 not less than 50 nor more than 170 at 125° C. and a powdery material, containing powder whose specific gravity is not less than 12 as a main component thereof, added to the EPDM at not less than 80 wt % nor more than 97.5 wt % of a whole amount of the high specific-gravity EPDM composition.
摘要:
A high specific-gravity EPDM composition consisting of a mixture of EPDM containing diene at less than 4.5 wt% and ethylene at not less than 58 wt% nor more than 80 wt% and having a Mooney viscosity ML 1+4 not less than 50 nor more than 170 at 125°C and a powdery material, containing powder whose specific gravity is not less than 12 as a main component thereof, added to the EPDM at not less than 80 wt% nor more than 97.5 wt% of a whole amount of the high specific-gravity EPDM composition.
摘要:
Bei einem Ballschäger, insbesondere Tennischläger (2) mit einem Schlägerkopf und einem Griffteil (3), wobei die Rahmenholme (1) sich vom Griffteil (3) über den bespannten Bereich des Kopfteiles erstrecken, bei welchem die offene Fläche zwischen den spitzwinkelig in den Griffteil mündenden Rahmenholmen (1) zur Gänze die Bespannungsebene bildet und die in Schlägerlängsachse verlaufende längste mittlere Saite (4) zwischen dem Kopf und dem den Griff benachbarten Ursprung des spitzen Winkels (α) der in den Griffteil (3) mündenden Rahmenholme (1) gespannt ist, weist der Schläger (2) ein bespanntes Gewicht von weniger als 260 g und eine Frei-Frei Eigenschwingungsfrequenz von größer 200 Hz auf. Das Verhältnis der Breite der bespannten Fläche zur Länge der längsten Saite der bespannten Fläche ist kleiner 0,6.