WO1995011626A1

WO1995011626A1 - Arrangement for the measurement of mechanical power and work

Info

Publication number: WO1995011626A1
Application number: PCT/FI1994/000465
Authority: WO
Inventors: Kalevi Artturi Nieminen
Original assignee: Kalevi Artturi Nieminen
Priority date: 1993-10-28
Filing date: 1994-10-17
Publication date: 1995-05-04
Also published as: FI93578C; AU7857094A; EP0725595A1; FI93578B; FI934770A0

Abstract

A measurement arrangement by which we can measure the power directed at a transmission device, required in the calculation of the power and work transmitted by a flexible transmission device, such as a chain, belts, a rope and a cable wire. In the arrangement the other axle is parallel with the transmission device, suspended on a bar or levers, and moves decelerated by a spring or springs. The movement is in proportion to the power which affects the transmission device. We can calculate the force by measuring the extent of the movement.

Description

ARRANGEMENT FOR THE MEASUREMENT OF MECHANICAL POWER AND WORK

The subject of the invention is a measurement arrangement with which we can measure power which affects a transmission device and is parallel with it, required in the calculation of the power and work transmitted by a flexible transmission device, such as a chain, various belts, a rope or a cable wire. The invention can be applied. among other things, to a bicycle, for the measurement of the power and work consumed by the bicyclist while pedalling. As we know from mechanics, h P = F x v and P = M x ω and W = I P x d t. where P = power t- W = work F = force v = velocity of power parallel with it M = moment ω= angular velocity of moment t = time

For example, the power transmitted by a chain can be calculated when we know the force parallel with the chain and the velocity of the chain. The electric messages issued by velocity and force sensors are multiplied with each other in electronic calculation circuits, and thus we obtain the value of the power. The labor consumed within a certain time period is calculated in an integration circuit. The calculated values can be shown during the ride on a display unit which is placed on the handle bar. .Arrangements suitable for calculating the power and work transmitted by a chain etc. have previously been presented in patent documents, such as for example USA patent 4.141.245 and German documents DE 3330525 A 1 and DT 2524605 A 1.

Using these in e.g. bicycles would, however, be expensive and therefore the applicant suggests a different, simpler solution. In it the axle of the other wheel, or in case of a bicycle, its boss is fastened in a "swimming method^" so that it can make a small movement in the direction of application of the chain power. Characteristic of the invention is that which has been presented in the characterization part of the patent requirements.

The most significant benefit of the invention is its simple and inexpensive structure, which makes it possible to be used in "everyman^'s^" devices. Below we explain the invention in detail and with the help of figures. Fig. 1 shows one application of the invention installed in a bicycle, as seen from the side. In it the boss (3) can slide on slide bars (7). The spring (10) resists the movement. Fig. 2 shows the boss (3) as seen from direction A. Fig. 3 shows an application in which the boss is suspended like a pendulum on plate levers (6). It also has a pressure spring (10). Fig. 4 shows Fig. 3 as seen from direction B. Fig. 5 shows the boss (3) installed on the slide bars (7) above and below it. The movement is resisted by cup springs ( 1 1). Fig. 6 shows an application in which the boss is suspended on a torsion spring (9) through levers (6). Fig. 7 shows an application like the one in Fig. 3, in which the spring is a bending spring/bending springs (12). Fig. 8 shows an application in which the boss (3) is suspended on a bending element (13) attached to the frame. When we pedal the bicycle the driving torque achieved with the pedals moves to rotate the back wheel through the chain. A supporting force the size of the chain force is directed at the boss (3) of the wheel. When we measure this force and multiply it with the velocity of the chain, the result is the power consumed in pedalling. The supporting force, which is the size of the chain force and is directed at the boss, is in proportion to the transition parallel with the chain and allowed by the suspension mechanism, which transition is resisted with the help of a spring arrangement. When we know the spring constant of the spring or springs, we can find out the extent of the force directed at the boss by measuring its transition. We can measure the transition of the boss with some previously known method which gives an electric message. We can also measure the velocity of the chain with some previously known method. As supporting variations of the boss (3) we can use various bar and lever mechanisms which are known from machine construction. Fig. 1, 3, 5, 6 and 8 are only examples of these.

As measurement springs we can use various springs, such as cylinder springs (extension and pressure), cup springs, ring springs, torsion and bending springs, rubber and plastic cushions etc. The force which affects the boss can also be measured by using, in applications like the ones in Fig. 7 and 8, a strain gauge to measure the bending or cutting force.

A calculation and display unit with the necessary adjustment and calibration possibilities, which takes its current from a battery, an accumulator or a dynamo can be attached to the handle bar with a quick-release lock, for example. In the above the invention has been dealt with mainly as applied to a bicycle. It can, however, also be applied to various forms of transmission which occurs through a flexible transmission device, such as a chain, various belts, a rope and a cable wire. The structural solutions shown here can be varied within the framework of the invention idea specified by the patent requirements.

Claims

PATENT CLAIMS

1. An arrangement for the measurement of the power and work transmitted by a flexible machine element, such as a chain (18), belts, a rope and a cable wire, between two wheels (17, 19), in which the power is calculated as the input of the force directed at the transmission device and its velocity, and the work is calculated by integrating the power in proportion to the time, k n o w n for the fact that the axle (3) of the other wheel can move, resisted by a spring or springs (10, 1 1 , 12) or a spring cushion, in the direction of the force transmitted by the transmission device, in proportion to this force, which movement is used to measure the force.

2. A measurement arrangement in accordance with patent requirement 1 , k n o w n for the fact that the axle which moves in the direction of the force transmitted by the transmission device (18) and which is resisted by a spring or springs (10, 1 1 , 12) or a spring cushion, is the center axle (3) of the bicycle, and the transmission parallel with its chain power is in proportion to the current forces directed at the pedals, whose extent can be measured with this movement.

3. A measurement arrangement in accordance with patent requirement 1 , k n o w n for the fact that the movement possibility of the axle (3) is realized with slide bars (4, 5, 7).

4 A measurement arrangement in accordance with patent requirement 1. k n o w n for the fact that the movement possibility of the axle (3) occurs with the help of supporting levers (6) or lever mechanism, and geometry is taken into account in the calculation.

5. A measurement arrangement in accordance with patent requirement 1 , k n o w n for the fact that the movement possibility of the axle (3) occurs with the help of a flexible element (13), on which it is fastened.