GB2318675A

GB2318675A - Simple machines kit

Info

Publication number: GB2318675A
Application number: GB9620864A
Authority: GB
Inventors: David Eckold
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-10-07
Filing date: 1996-10-07
Publication date: 1998-04-29
Also published as: GB9620864D0

Abstract

An educational kit comprising model apparatus as illustrated in figures 3 to 7 which demonstrate the mechanical advantage gained through using mechanical devices known as simple machines. Each device is used in conjunction with a weight 1 which can be raised by each device in turn. The amount of force required to raise the weight is measured by a force meter 6 so that the force required to raise the weight with the aid of each type of device can be compared with the amount of force required to raise the weight directly without mechanical aid. The kit may also be used to demonstrate the mechanical advantage of the inclined plane, the wedge, the wheel and axle and the screw.

Description

Simple Machines Kit This invention relates to an educational kit for exploring and testing the six basic mechanical devices known as 'Simple Machines'. The kit is particularly intended for use in schools and an object is to produce a simple kit from which a teacher or pupils can explore and demonstrate the principles behind each of the Simple Machines.

The kit preferably includes, a set of known weights with fixings by which they can be pulled or attached to a measuring device and which are ideally formed from bottles of known capacity which can be filled to a specified level with water to form suitable weights, force meters used to measure the amount of force exerted upon a machine, a flat beam wide enough to accommodate a weight and with a member fixed to one end to prevent the weight from sliding off the beam and a fixing at its opposite end to which a measuring device can be attached and used with a block which functions as a fulcrum and which are together used with a weight and a force meter to demonstrate the principles of a Lever, a flat beam wide enough to accommodate a weight, and with a smooth surface to minimise the friction between it and the weight, which is used with a block to support the beam forming a ramp which is used together with a weight and force meter to demonstrate the principles of an Inclined Plane, a wedge shaped block with a fixing at its thin end by which it can be attached to a measuring device and which is used with an 'L' shaped block that is held stationary and holds a weight in position while the wedge is pulled by its fixing thereby raising the weight and used together with a force meter to demonstrate the principles of a Wedge, a round sectioned rod passing through the centre of a larger diameter disc each fitted with a cord and with a hollow round sectioned tube which can be passed over one end of the rod to form a bearing which allows the rod and disc to turn freely so that as a cord wrapped around the disc is pulled the disc turns turning the rod and winding the cord attached to the rod causing the weight attached to it to rise and together used with a force meter to demonstrate a Wheel and Axle, a channel sectioned block with threaded bores through each of the two extended arms which aliow a threaded rod to turn freely and move up and down as it turns and where the threaded rod has a fixing at one end onto which a weight is attached and also has a cord attached that is wrapped around the rod so that when the cord is pulled the threaded rod revolves and moves upward through the threaded ends of the block raising the weight and which is used together with force meter to demonstrate the principles of the Screw.

One embodiment of the kit in accordance with the invention will now be described by way of example only with reference to the accompanying drawings of which Figure 1 is a perspective view of a Weight Figure 2 is a perspective view of a Force Meter Figure 3 is a perspective view of a device used to demonstrate the Lever Figure 4 is a perspective view of a device used to demonstrate the Inclined Plane Figure 5 is a perspective view of a device used to demonstrate the Wedge Figure 6 is a perspective view of a device used to demonstrate the Wheel and Axle Figure 7 is a perspective view of a device used to demonstrate the Screw The kit comprises one or more weights 1 comprising a bottle which can be filled with water and which has a loop 3 attached to its removable top 4 and a band 5 around the main body of the bottle. The loop at the top of the bottle and the band around the body of the bottle is to enable the weight to be connected to a measuring device and/or one of the mechanisms described here. The kit also comprises one or more force meters 6 used to measure the force applied to each of the mechanisms. The force meter comprises a tube 7 which passes easily through the block 9 which is fixed to a back panel 10 which has a scale marked on it and the tube has a hook shaped member 11 at one end which is a friction fit and traps one end of an elastic strip 12 when the hook is fitted into the end of the tube 7 and where the other end of the elastic strip 12 passes through a bore in the block 8 through which the tube 7 cannot pass and the elastic strip 12 is in turn held in position by a peg 13 so that when a load is put on the hook 11 the tube 7 passes through the block 9 as the elastic strip 12 is extended and the position of the top of the tube 14 in relation to the scale on the panel 10 indicates the amount of force applied to the meter.

The kit also comprises a wide beam 15 with a member 16 attached at one end to prevent the weight 1 from sliding off and a hole 16a at its other end where a force meter 6 is attached and a block 17 is positioned in the middle as a fulcrum. The beam 15 and block 17 are positioned near the edge of a table or similar support 18 so that the force meter 6 can be pulled down and the effect of the beam 15 acting as a lever as it raises the weight 1 is indicated on the scale on the force meter 6.

The kit also comprises a flat wide beam 19 which is smooth on its upper surface 20 and which has a member 21 near to one end which secures it against a block 22 which together form a ramp along which the weight 1 is pulled by a force meter 6 attached to the band 5 on the weight so that the scale on the force meter indicates the effect of the beam 19 which acts as an inclined plane as the weight 1 is raised along the beam 19.

The kit also comprises a triangular shaped block 23 with a hook shaped member 24 at the small end of the block 23 and a block 25 with a round rod 26 fixed at ninety degrees to the block 25 and which is the same length as the width of the triangular shaped block 23 and which is mounted higher on the block 25 than the height of the block 23 at its highest. The block 25 is positioned over the lowest end of the triangular block 23 and in front of the weight 1 in order to prevent the weight 1 from moving forward as the triangular block is pulled forward by the force meter 6 attached to the hook shaped member 24 at the front of the triangular block 23. As the force meter is pulled the triangular block 23 acts as a wedge as the weight is lifted and the effect of the wedge is indicated on the force meter 6.

The kit also comprises a rod 27 which passes through the centre of a round disc 28 of larger diameter than the rod 27 and which is fixed to it halfway along the length of the rod 27. A round tubular sectioned component 28a with an internal bore just greater than the diameter of the rod 27 forms a bearing which can be held allowing the rod 27 and disc 28 to revolve freely. One end of a cord 29 is attached to the rod 27 and the other end of the cord 29 has a hook shaped member 30 which can be attached to a weight 1. One end of a second cord 31 is attached to the disc 28 and is wrapped around the disc 28 several times and the other end of the cord 31 has a loop fixed to it so that it can be connected to a force meter 6. As the force meter is pulled the cord 31 is pulled and the disc 28 rotates and in turn the rod 27 rotates and as it does the cord 29 is wrapped around the rod 27 and the weight 1 is raised. The effect of the rod 27 and disc 28 acting as a wheel and axle in raising the weight is indicated on the force meter.

The kit also comprises a rod 32 with a spiral thread running along its length and which is held in a holder 33 which has an extended part 34 at the top and a second extended part 35 at the bottom. The two extended parts each have a spiral threaded bore 36 which allows the threaded rod 32 to rotate within them and as the threaded rod 32 rotates within the bores 36 the rod is caused to move up or down as a result of the spiralled thread. The rod 32 has a hook shaped member 37 attached to the end 38 which is positioned downwards and which is connected to a weight 1. A cord 39 is attached at one of its ends to the rod 32 between the two extended parts 34 and 35 and has a loop 40 at its other end which is attached to a force meter 6. The cord 39 is wrapped around the rod 32 while the rod 32 is in its lowest position in relation to the extended arms 34 and 35. As the cord 39 is pulled the rod 32 rotated and as it does so it rises through the extended arms 34 and 35 and the weight rises. The effect of the rod acting as a screw in raising the weight is indicated by the scale on the force meter.

Claims

1. An educational kit for exploring and testing basic mechanical devices known as 'Simple Machines' comprising pieces of apparatus of which one can be used to demonstrate the function of a lever, another can be used to demonstrate the function of a wheel and axle, another can be used to demonstrate the function of an inclined plane, another can be used to demonstrate the function of a screw and another can be used to demonstrate the function of a wedge and each is used in combination with an attachable weight and an attachable force meter in order to demonstrate the mechanical advantage gained by the use of each type of simple machine.

2. An educational kit according to claim 1 which includes a device comprising a flat beam wide enough to accommodate a weight and with a member fixed to one end to prevent the weight from sliding off the beam and a fixing at its opposite end to which a force meter can be attached and which is used with a block underneath the beam which functions as a fulcrum so that when a force meter attached to the beam is pulled the weight which is positioned on the opposite end of the beam is raised and the amount of force required to raise the weight is indicated on the force meter.

3. An educational kit according to claim 1 or claim 2 which includes a device comprising a flat beam wide enough to accommodate a weight and with a smooth surface to reduce friction between it and the weight and which is used with a block to support the beam to form a ramp and where a force meter is attached to the weight sitting on the ramp and the force meter is pulled raising the weight up the ramp and the amount of force required to raise the weight is indicated on the force meter.

4. An educational kit according to claims 1 to 3 which includes a device comprising a wedge shaped block with a fixing at its thin end by which it can be attached to a force meter and which is used with a stationary block which holds a weight in position on the wedge shaped block so that when the wedge shaped block is pulled by the force meter the weight is raised and the amount of force required to raise the weight is indicated on the force meter.

5. An educational kit according to claims 1 to 4 which includes a device comprising a round sectioned rod fixed through the centre of a larger diameter disc each fitted with a cord and with a round sectioned tube which can be passed over one end of the rod to form a bearing which allows the rod and disc to turn freely so that as the cord wrapped around the disc is pulled by a force meter attached to it the disc turns the rod and winds the cord attached to the rod causing a weight attached to this cord to rise and the amount of force required to raise the weight is indicated on the force meter.

6. An educational kit according to claims 1 to 5 which includes a device comprising of a channel sectioned block with threaded bores through each of the two extended arms which allow a threaded rod to turn freely and move up and down as it turns and where the threaded rod has a fixing at one end onto which a weight is attached and a cord is attached and wrapped around the threaded rod so that when a force meter attached to the cord is pulled the threaded rod turns and raises the weight and the amount of force required to raise the weight is indicated on the force meter.