CN201897893U

CN201897893U - Device for proving force parallelogram rule

Info

Publication number: CN201897893U
Application number: CN201020627540XU
Authority: CN
Inventors: 麦韵诗
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-11-27
Filing date: 2010-11-27
Publication date: 2011-07-13
Anticipated expiration: 2020-11-27

Abstract

The utility model discloses a device for proving a force parallelogram rule. The device comprises an iron plate, a fixed leg and more than two dynamometers are arranged on the front side of the iron plate, and magnets for fixing the dynamometers onto the iron plate are arranged on the back of the iron plate in positions corresponding to the dynamometers. By adopting the structure, the device has small error, convenience in operation, and good safety performance.

Description

Parallelogram of forces rule demo plant

Technical field

The utility model relates to parallelogram of forces rule demo plant.

Background technology

The step of checking parallelogram of forces rule is:

1. the fixing A point onboard of an end of rubber bar.

2. with the other end of two cords knot at the rubber bar, with two spring balance rubber bars that draw at an angle to each other, the rubber bar extends, and makes node be elongated to the O point by cord.

3. the direction of following two cords is drawn in the position that the O that takes notes with a pencil is down ordered, and writes down the reading of two dynamometers.

4. on paper, make the diagram of two power F1, F2 in proportion, obtain F with joint efforts with parallelogram rule.

5. only use a dynamometer, by cord the node on the rubber bar is moved to same position O point, write down the direction of the reading and the cord of dynamometer, make the diagram of this power F ' in same ratio, the F that makes a concerted effort that compares F ' and try to achieve with parallelogram rule, whether the size of relatively making a concerted effort equates whether direction is identical.

6. change angle and the size of F1 and F2, do again twice.

In present teaching, rubber bar fixedly fixing by drawing pin like this, repeatedly after the experiment, comes off or loosening easily, and one conveniently can cause error to experiment, dangerous on the other hand.In addition, reduce the error between F ' and the F, then guarantee rubber bar, stay cord and dynamometer as far as possible in same plane, but when using dynamometer now, control, therefore, be difficult to guarantee that above-mentioned three is in same plane by staff.Have, in teaching process, because dynamometer needs two hands to control, also want the size and Orientation of deterministic force, therefore, a people can't finish this experiment, needs plural people at least, and inconvenience operates.

Summary of the invention

The purpose of this utility model provides a kind of parallelogram of forces rule demo plant, utilizes structure of the present utility model, and error is little, and is easy to operate, and security is good.

For achieving the above object, parallelogram of forces rule demo plant comprises iron plate, and the front of iron plate is provided with a fixed leg and plural dynamometer, is provided with dynamometer is fixed on magnet on the iron plate on the back side of iron plate and the corresponding position of dynamometer.

The beneficial effects of the utility model are: because dynamometer is provided in a side of the front of iron plate, and be pull-in on the iron plate by magnet, promptly dynamometer is fixed with respect to iron plate, therefore, be easy to guarantee that rubber bar, stay cord and dynamometer are in the same plane, reduce experimental error; Owing to adopted fixed leg, with respect to the drawing pin of prior art, be not easy to become flexible or come off, therefore, safe in utilization; Because dynamometer is fixed on the iron plate by magnet, therefore, dynamometer can slide on iron plate, and is on the optional position, and a people just can finish in experimentation, and is like this, easy to operate.

Description of drawings

Fig. 1 is a front view of the present utility model.

Fig. 2 is a rear view of the present utility model.

Embodiment

Below in conjunction with the drawings and specific embodiments the utility model is further elaborated.

As depicted in figs. 1 and 2, parallelogram of forces rule demo plant comprises iron plate 1, the front of iron plate 1 is provided with a fixed leg 2 and plural dynamometer 3, be provided with on the back side of iron plate and the corresponding position of dynamometer dynamometer is fixed on magnet 4 on the iron plate, described fixed leg is a screw.In the present embodiment, dynamometry is counted two.

Utilize the experimental procedure of demo plant of the present utility model to be:

1. an end of rubber bar 5 is fixed on the screw.

2. with the other end of two cords, 6 knots at the rubber bar, by two dynamometers of cord 6 usefulness, the 3 rubber bars 5 that draw at an angle to each other, 5 elongations of rubber bar make node be elongated to the O point.

6. change angle and the size of F1 and F2, do again twice.

The utility model is because dynamometer is provided in a side of the front of iron plate, and is pull-in on the iron plate by magnet, and promptly dynamometer is fixed with respect to iron plate, therefore, is easy to guarantee that rubber bar, stay cord and dynamometer are in the same plane, reduces experimental error; Owing to adopted fixed leg, with respect to the drawing pin of prior art, be not easy to become flexible or come off, therefore, safe in utilization; Because dynamometer is fixed on the iron plate by magnet, therefore, dynamometer can slide on iron plate, and is on the optional position, and a people just can finish in experimentation, and is like this, easy to operate.

Claims

1. parallelogram of forces rule demo plant, it is characterized in that: comprise iron plate, the front of iron plate is provided with a fixed leg and plural dynamometer, is provided with dynamometer is fixed on magnet on the iron plate on the back side of iron plate and the corresponding position of dynamometer.

2. parallelogram rule demo plant according to claim 1 is characterized in that: described fixed leg is a screw.