SE419960B - DEVICE FOR VARYING THE PEDAL TISSUE LENGTH OF A CYCLE - Google Patents

Abstract

1. A pedal for bicycles with - as to its length - variable pedal arms (12), and each having a pedal and a pedal shaft (13), which is attached to the pedal arm (12) adjustable to different optional positions relative to the attachment pin (15) of the pedal arm, characterized thereby, that the pedal shaft (13) is shaped in one piece as a crankshaft, a first crank pin (14) of which in a manner known per se, is rotatable in bearings (16) in the pedal (11) and the second crank pin (15) is rotable in a bearing (23) in the pedal shaft (12), that the first crank pin (14) cooperates with a freewheel hub (18), which at a forward pedaling motion takes up a frewheel position, and which at reaward pedaling motion interconnects the first crank pin and the pedal (11) in a non-rotatable manner, and that a torsional resistance (25) acts upon the second crank (15), whereby in a manner known per se, by means of spring force or the like, the second crank pin (15) is adjustable to different, predetermined angular positions relative to the pedal arm (12).

Description

7910658-9 Fig. 2 shows a part of the crank arm in front view.

Fig. 3 shows a section along the line III - III in Fig. 1.

Description_of embodiment In the drawing, ll denotes a bicycle pedal, with 12 one crank hot and with 13 a pedal shaft. This is designed as one crankshaft with a longer shaft journal 14 and an eccentric in front holding to this arranged shorter shaft journal 15. The long one the shaft journal lä is rotatably mounted in via roller bearings 16 a bore 17 in the pedal ll. On the pedal shaft 13 is arranged a free end 18, which is surrounded by a bushing 19, which at one the end is provided with cut-outs 20, which cooperate with i the pedal housing 11 fixedly mounted lugs 21. As can be seen from fig. 3, the cut-outs 20 are so large that the sleeve can be turned approx 70 ° against the action of a spring 22, one end of which is connected with the sleeve 19, while the opposite end is connected to the pedal ll. The free hub 18 is designed to allow free rotation. tion of the pedal shaft in one direction of rotation while in the opposite direction the pedal shaft 13 is locked in relation to the bus 19.

The shorter shaft pin 15 of the pedal shaft 13 is, as stated, eccentric arranged relative to the longer shaft pin 14, the eccentric the density suitably amounts to between 6-10 mm. The crank arm 12 is rotatably mounted on a shaft by means of a sliding bearing 25 pin 15 and fixed to it by means of a nut 2ü. IN the crank arm 12 is built into a spring-loaded rotary resistor 25 comprising a ball 26, as of a spring 2? pressed against the shaft journal 15 and cooperates with devices arranged on its mantle surface. specializations 28. I The force of the spring 27 is so selected that a sufficient large torsional resistance is obtained for the shaft journal 15 to held in its selected position relative to the crank arm 12.

When cycling, i.e. when the crank arm 12 is caused to perform a clockwise rotational movement, the shaft journal lü will 7910658-9 rotate around the pedal 11 while the shaft journal 15 is stationary relative to the crank arm 12. On the other hand, the pedal crank is stepped back, ie in the opposite direction of rotation, the freewheel will lock the shaft pin lü to the bushing 19, whereby at continued movement backwards the pedal shaft 13 will be rotated about the shaft the pin 15 against the action of the torsional resistance 25, until the ball 26 has snapped into the next recess 28 on the shaft journal 15 mantelyta.

In order that unwanted adjustments of the pedal crank do not occur in the case of minor backward trampling, the freewheel 18 is arranged in said bushing 19, which is limited rotatable in the pedal 11.

When the pedal is released or the crank arm 12 is rotated clockwise, the spring 22 will turn the bushing 19 back to its starting position, so that at the next backward movement of crank arm a new adjustment of the crank arm relative to the shaft pin 15 can be made.

With the device according to the invention, for example, the length of the arm changes so that in one position a crank length of 165 mm is obtained, in a second position a crank length of 170 mm, in a third position a crank length of 175 mm and in a fourth position a crank length of 180 mm. In case of continued backward trampling the eccentricity will decrease again until the first the initial position has been reached.

The invention is not limited to the embodiment shown. the form without a number of variations is conceivable within framework of the claims.

Claims (2)

'7919658-9 P A T E N T K R A V Device for bicycles with pedal cranks variable in their effective length, each comprising a crank arm (12), a pedal shaft (13) and a pedal (II), the pedal shaft (13) being attached to the crank arm (12) and arranged to take on different selectable positions around the point of attachment in the crank arm, characterized in that the pedal shaft (13) is formed in one piece as a crankshaft, one shaft pin (l fl) of which is rotatable in known manner in bearings (16) in the pedal (II). and whose second shaft pin (15) is rotatable in a bearing (23) in the crank arm (12), that the shaft pin (IN) of the pedal (II) cooperates with a free cutter (18), which allows free rotation in a direction of rotation and locking of the pedal to the shaft journal (lä) in the opposite direction, while on the second shaft journal (15) of the pedal shaft (13) a rotational resistance (25) is arranged which in a known manner holds the shaft journal (15) in different angular positions relative to the crank arm (12). Device according to claim 1, characterized in that the free hub (18) is arranged in a rotatable bushing (19) limited in the pedal (11), which is rotatable between two end positions against the action of a spring (22), which limited by locking lugs (21) arranged in the pedal and arranged with the bushing.