CN2704075Y

CN2704075Y - Lever balance demonstrating teaching aid

Info

Publication number: CN2704075Y
Application number: CN 200420016304
Authority: CN
Inventors: 侯召宇; 王荣爱; 曹鹤飞; 张淑肖; 李全胜
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-06-07
Filing date: 2004-06-07
Publication date: 2005-06-08
Anticipated expiration: 2014-06-07

Abstract

The utility model discloses a lever balance demonstrating teaching aid. A sliding bar which can slide up and down along a bracket post and can move right and left is installed on a post of a lever bracket. One end of the sliding bar is provided with a fixed pulley. A weight suspending line which is positioned at one side which is provided with the fixed pulley passes through the fixed pulley. A length measuring line is connected with a lever fulcrum. A right angle measurer is arranged on the length measuring line. When the utility model is adopted, the sliding bar with the fixed pulley and the length measuring line are additionally arranged on the ordinary lever bracket, the acting forces with different directions can be displayed in an intuitionistic mode. The force arm can be measured even if the action line of force and the lever are in non-right angle state, and the force moment can be obtained by the product of the force and the force arm; thereby, the principle that the lever is in balance when the force moment is equal can be testified.

Description

The lever balance demonstration teaching aid

Technical field

The utility model relates to a kind of mechanics teaching aid, especially a kind of teaching aid of demonstrating the equal lever balance theory of moment.

Background technology

In physics teaching, existing common lever teaching aid is made up of support and lever, in use must keep line of action of force vertical with lever, just can give expression to the principle that moment equates lever balance, when line of action of force and lever out of plumb, then can't demonstrate, the teacher can only have significant limitation at the blackboard drawing illustrate, and student's understanding is had any problem.

Summary of the invention

The utility model provides under a kind of power and the arm of force out of plumb situation also can demonstrate and give expression to the demonstration teaching aid that moment equates lever balance theory.

The technical solution adopted in the utility model is: the lever balance demonstration teaching aid, comprise support, be loaded on the lever on the bracket upright post and be divided into lever and the bracket upright post intersection point is the balance pivot both sides and the weight suspension line that can slide along lever, on bracket upright post, be equipped with one and can slide up and down also the slide bar of its move left and right relatively along it, one end of slide bar is provided with fixed pulley, the weight suspension line that is provided with fixed pulley one side passes from fixed pulley, be connected with a linear measure longimetry line at the balance pivot place, on this linear measure longimetry line, be provided with the vertical angle measurement device.

Described vertical angle measurement device is to be connected to form by orthogonal straight tube and straight line pole, and straight tube is sleeved on the linear measure longimetry line; The vertical angle measurement device also can be angle square.

The utility model is by increasing the slide bar and the linear measure longimetry line of band fixed pulley on the common lever support, just can demonstrate the acting force of different directions intuitively, become under the non-perpendicular angle situation with lever at line of action of force and also can measure the arm of force, product by the power and the arm of force obtains its moment, and then verifies that lever keeps principle for balance under the equal situation of moment.

Description of drawings

Fig. 1 is the utility model user mode structural representation.

Embodiment

Below in conjunction with the drawings and specific embodiments the utility model is described further:

The lever balance demonstration teaching aid comprises support 11, is loaded on the lever 1 on the bracket upright post 5 and is divided into lever and the bracket upright post intersection point is balance pivot 10 both sides and the weight suspension line 12,13 that can slide along lever, one slide bar 6 is housed on bracket upright post 5, this slide bar 6 and bracket upright post 5 are connected by sliding sleeve, sliding sleeve is provided with control handle 4 outward, knob 4 is unscrewed, slide bar 6 just can slide up and down also column move left and right relatively along bracket upright post 5, one end of slide bar 6 is provided with fixed pulley 8, and the weight suspension line 13 that is provided with fixed pulley one side passes from fixed pulley 8.Be connected with a linear measure longimetry line 2 at balance pivot 10 places, be set with outside this linear measure longimetry line by straight tube and the vertical angle measurement device 3 formed with this straight tube straight line pole connected vertically, straight tube is enclosed within on the linear measure longimetry line 2 and can moves along linear measure longimetry line 2.Whether this vertical angle measurement device also can be angle square or other form certainly, as long as it possesses a right angle, can measure two lines and vertically get final product.

During use, on the suspension line 12 of lever one end, hang counterweight 9, the suspension line 13 of the other end passes the fixed pulley 8 of slide bar 6, the lower end hangs counterweight, by regulating control handle 4, move left and right slide bar 6, make line of action of force not vertical mutually with lever 1, and the mobile lever 1 maintenance level that makes by slide bar 6, this moment linear measure longimetry line 2 is moved to the position of the suspension line 13 that passes fixed pulley, with vertical angle measurement device 3 is reference, linear measure longimetry line 2 and suspension line 13 kept vertical, and 13 vertical range is the arm of force from balance pivot 10 to suspension line, by the just readable size that goes out the arm of force of linear measure longimetry line 2, thereby verify left power * left arm of force=right power * right arm of force, moment equates lever balance.

Claims

1, a kind of lever balance demonstration teaching aid, comprise support (11), be loaded on the lever (1) on the bracket upright post (5) and be divided into lever and the bracket upright post intersection point is balance pivot (10) both sides and the weight suspension line (12) that can slide along lever, (13), it is characterized in that: on bracket upright post (5), be equipped with one and can slide up and down also the slide bar of bracket upright post move left and right (6) relatively along bracket upright post, one end of slide bar (6) is provided with fixed pulley (8), the weight suspension line (13) that is provided with fixed pulley one side passes from fixed pulley (8), locate to be connected with a linear measure longimetry line (2) at balance pivot (10), on this linear measure longimetry line, be provided with vertical angle measurement device (3).

2, lever balance demonstration teaching aid according to claim 1 is characterized in that: described vertical angle measurement device (3) is to be connected to form by orthogonal straight tube and straight line pole, and straight tube is sleeved on linear measure longimetry line (2) and goes up also and can slide along linear measure longimetry line (2).

3, lever balance demonstration teaching aid according to claim 1 is characterized in that: described vertical angle measurement device is an angle square.