DE51904C - Device for changing the speed of bicycles with chain drive - Google Patents

Description

IMPERIAL

PATENT OFFICE.

PATENT LETTERING

CLASS 63: Saddlery and wagon construction.

Fatentirt in the German Empire from September 6, 1889.

If the gear ratio on a bicycle is chosen in such a way that the rider on even ground can move continuously at great speed, it is usually not possible to negotiate significant gradients of the street, and a second smaller one Translation that requires labor becomes an urgent need here. Many previously known devices which are intended to meet this need suffer from two main faults: either the set-up puts too much strain on the bike or the device causes not only when driving uphill but also when driving flat route unnecessary friction losses, which are synonymous with wasted energy, whereby the benefits gained in mountain climbing are again consumed; -in other constructions but changing the translation requires so much time that it cannot be done during the Driving can be accomplished.

The device described later, which causes an additional weight of only 1 to 2 kg, enables the driver without getting off by simply moving a lever to change the two ratios, and it occurs while driving no friction losses on the level 'way.

Fig. Ι of the accompanying drawings shows a cross section of the drive mechanism and

Fig. 2 is a front view of the same.

In Fig. Ι α is the crank axle bearing, which is attached to the frame G of the bicycle. In this camp, the chain wheel b and the transmission wheel c rotate on balls i. b and c are connected to one another in that their hubs are shaped as claw couplings and are held in a concentric position to one another by the sleeve d, which is pushed over, and which is screwed to b.

In these coupled wheel hubs b and c , the actual crank axle /, which is provided with crank g on the left and crank h on the right, rotates on balls e . A drive plate k is attached to crank g and a transmission gearwheel / is attached to crank h.

Two further, firmly connected gears m and η rotate on balls ο around an axis p, which sits on the lever q , q itself rotates around a pin r, which is attached to the bicycle frame.

The rod s, movably connected to q , is used to raise and lower q, whereby the gears m and η sitting on q are in and out of engagement with the gears Z respectively. c to be brought.

Bar 5 is provided with a handle near the saddle and guided in a bracket, in which it can be established in its three different positions by entering a springy pen.

On the spokes of the chain wheel b , diametrically opposite, two locking latches t are rotatably attached (see Figs. 4 and 5), which, moved by small springs i ² , engage with their front hook-shaped part in corresponding grooves of the drive plate k and thereby create a Connect chain wheel b and crank axle.

Each locking latch t carries a small steel roller t ¹ to trigger it (see FIGS. 6 a and 6 b).

The connection between chain

wheel b and crank axis through a disc v provided with eccentric lugs, FIGS. 3 and 4, which is connected to a ring v ^{2 by three bands v 1} .

Disk ν and ring v ² can be moved horizontally on the crank axle bearing α.

One of the bands v ^l (see FIGS. 4 and 5) carries a pin v ³ , on which the small angle lever χ connected to lever q by rod s ¹ acts. Lever χ rotates on a pin x ¹ (Fig. 1), which is attached to the frame G. It is used to move the rod s, transmitted by lever q, rod s ¹ and angle lever x, also to move the disk v.

When driving on level ground, rod s is raised with lever q and held in this position by some known device. As a result, the transmission gears m and η are brought into engagement and the ring v ² and disk ν are pushed to the right, whereby the locking hooks t of the sprocket b lower and engage the drive plate k , so sprocket b is directly connected to the crank axis f and both rotate together only on the balls i.

To go uphill, the rod s is lowered, thereby pushing the disk ν to the left; the rollers t ^l step into the cut-outs \ of the disk ν and run on them on the circumference of the disk ν (see Fig. 3), whereby the locking latches t are raised and come out of engagement with the disk k . Then by further lowering rod 5, the gears πι η with the gears / bezw. c engaged. Wheel / now moves Ot, and the wheel η connected to m moves wheel c and with it the chain wheel b, which is now driven at the speed that corresponds to the size ratios of the transmission wheels mn el.

When driving downhill, the rod s and the lever q can be hung in their middle positions. In this position, the wheels m η are not engaged with the wheels / c and the locking latch t is not yet engaged; So the cranks stand still and can serve as a support for the feet.

The readjustment of the bearings is effected by the nut y, Fig. I, which is seated on the thread of the axle / seat. Turning this nut to the right not only regulates the ball bearing e, but also the two wheels b and c are pushed into each other by the lateral pressure of the balls e until the balls i are in contact.

Claims (1)

Patent claim: An apparatus for changing speed of bicycles with chain drive, characterized by the arrangement of the b to the spokes of the sprocket mounted barrier traps tt, showing the same with the aid of the drive plate k directly with the crank axle coupling, v in connection with the winding disk which behufs change of Speed is pushed by suitable rods and angle levers under the rollers t ¹ t ^{1 of} the locking latches 11 and thereby lifts the latter out of the drive plate k and releases the coupling between the crank axle and the sprocket, but at the same time also a countershaft m 11 , which with the aforementioned rods in Connection is in engagement with the respectively with crank. Sprocket connected wheels c I brings, so that the movement of the cranks is only transmitted to the sprocket with the help of the back gear. For this purpose ι sheet of drawings.