SU1290396A2 - Teaching-aid device on mechanics - Google Patents

Abstract

The invention relates to educational devices in mechanics and allows demonstrating the direction of the reactions of supports to the effect of various types of loads on a beam. The device contains a base on which a loadable beam 6 is located in the fixed support 2 and the moving 3. The beam 6 can be loaded with one or several kinds of loads, for example, a constant acting torque generated by the action of two elastic connections, including the rod 26, springs 27 and a pusher 28 concentrated by the action of an elastic connection, including a spring 9 and a rod 10, and an adjustable moment opposite to the first one and formed by the action of elastic connections 20 and 21. If the moments created by two pairs uprug.ih s bonds will ravny-, the line supports and the direction of reactions acting peresekuts concentrated load at a single point. With a positive moment acting on the beam, the reaction of the fixed support will change its direction and pointer 7 will change its position closer to the vertical, with a negative moment closer to the horizontal. 2 Il. § (L 26 25 25 2Ts to; о о 00 co o to 1 Figure 1 Yu / 3 f 7

Description

The invention relates to educational devices in mechanics.

The aim of the invention is to expand the demonstration capabilities by demonstrating the response of the supports to the effect on the beam of various types of loads.

Figure 1 shows the device, a general view; figure 2 - section aa in figure 1.

The training device consists of the base 1, on which the fixed support 2 is installed, the Hinge 3 of the support 2 is designed as a crank, the extreme axes 4 of which are installed in the support 2, and the middle axis 5 is placed in the beam 6. The direction of the reaction of the hinge 3 shows the pointer 7 which is rigidly connected to the axis 4 and is directed along the line connecting the centers of the axes 4 and 5 in the corresponding direction. The other end of the beam 6 rests on the movable support 8, the hinge of which is made exactly the same as the hinge 3 of the fixed support 2 and is provided with a pointer 7 of the direction of reaction of the hinge.

The device has an elastic connection consisting of springs 9 and a rod 10 interconnected by one end, the free ends of which by means of hinges 11 and 12 are connected respectively to the base 1 and the beam 6, and the indicator 13 of the direction of force rigidly connected to the rod 10 and located along it. The hinge 11 can move in a curvilinear slot 14, which is tightened so that, at different positions of the hinge 11, the spring 9 is tensioned with some force.

The device has a platform 16 installed on the base 1 with the possibility of movement in the guides 15 and two parallel levers 17 and 18 mounted on it, which are pivotally connected by one ends to each other, a bracket 19 rigidly connected to the beam 6, two additional elastic connections 20 and 21, located above and below the beam 6 parallel to it, each of which is connected at one end with a bracket 19, and the other with levers 17 and 18 and means for adjusting the force effect of elastic links 20 and 21 on the beam 6, having rigid coupling 22, pivotally associated with o free ends of levers 17 and 18.

five

0

five

0

five

0

five

0

five

The device may have one more pair of elastic connections, creating a constant torque. On the base 1, in the guides 23, the platform 24 and the lever 25 carrying the elastic connection are mounted for movement, the pike consists of a rod 26, a spring 27 and a pusher 28 made in the form of an arrow showing the direction of the force. The directions of the force indicators are chosen so that they show the true direction of the forces acting on beam 6. All elastic connections can be established in any quantity both between the supports of beam 6, and at its ends and outside of any of the supports.

The device works as follows.

In order to demonstrate the reaction of supports to the action of various types of loads, elastic connections are established at different parts of beam 6, and their indicators 13 and pushers 28 show the direction of the forces and, therefore, the type of load. For example, the beam shown in figure 1, there are three types of load: the torque, directed clockwise, the concentrated load and the torque, counterclockwise.

In this case, the direction of the reactions of the fixed support is determined by the direction of the indicator 7, the direction of reaction of the mobile support 8 is always vertical.

If the moments created by the elastic connections are equal, the direction lines of the reaction of the supports and the concentrated load intersect at one point, rotating the tension coupling 22, change the moment of forces acting on the beam. In the event of a positive moment, the reaction of the fixed support 2 changes its direction, while the pointer 7 turns a certain angle in the direction opposite to the clockwise movement, i.e. The pointer 7 takes a position closer to the vertical, when the force effect of a pair of elastic links on the beam is weakened, a negative moment occurs, while the pointer 7 takes a position closer to the horizontal.

Claims (1)

Invention Formula The training device for mechanics on the author. 1014005, distinguished by the fact that, in order to expand the demonstration capabilities by demonstrating the reactions of the supports to the action of various types of loads, it has been installed on the base with the ability to move in the guides of the platform and mounted on it two parallel levers that are hinged one end in between itself, the bracket ,. rigidly connected to the beam, two additional elastic connections, located above and below the beam parallel to it, each of which is connected at one end with a bracket and the other with levers mounted on the platform, and means for regulating the force action of elastic connections TH to the beam, which has a tie-in coupling, is pivotally connected to the free ends of the levers mounted on the platform. Fig