Field of the Invention
The invention relates to a self-propelled vibratory plate device for consolidating soil or the like. The vibratory plate device includes a wide plate operatively connected to an elongated control handle which is equipped with a deadman's handle that stops propelling the device, if the operator's grip on the control handle ceases.
Background of the Invention
It is already known that self-propelled machines of different kinds are equipped with safety devices of the deadman's handle type, but when it comes to vibratory plates it is less usual. Because heavier plates have considerable propulsion power and are often used in small spaces or where stationary barriers could exist, it is very desirable that they be equipped with the above-mentioned safety device that works independently of whether the motion is forwards, or backwards, so that it can prevent accidents or other types of damage.
Summary of the Invention
The particular invention refers to a self-propelled and hand-maneuvered vibratory plate equipped with an elongated control handle to control the plate device. The control handle is equipped with a deadman's handle. During the operation of the plate device the deadman's handle is held up. In this case, the vibratory plates are propelled by two, or more, eccentric counter-rotating parts. The rotating eccentric parts generate a resultant force the direction of which is variable. The eccentric parts in the invention are driven by an internal combustion engine via a centrifugal clutch. The centrifugal clutch is configured so that it drives the eccentric parts when the number of revolutions of the internal combustion engine is above idle speed. According to the invention, the deadman's handle is connected to the throttle of the internal combustion engine (gasoline motor) or to its fuel feed (diesel engine) in such a way that if the handle is inactive, the engine idles and when the handle is lifted up, the engine is set to working speed. If the handle is pressed down, beyond the inactive position, the ignition of the engine is short circuited (gasoline motor) or the fuel feed is interrupted completely (diesel engine) and the internal combustion engine stops.
Usually vibratory plates need only three speeds: stopped, idle, and working speed. With the arrangement of the invention, these three speeds can be obtained with only one control, the deadman's handle. Therefore, no separate speed control device of the internal combustion engine or no separate stop control is needed. It is also an advantage that the propulsion can be stopped with the engine speed decreased only to idle speed instead of to a complete stop. Therefore the plate could immediately be moved, for example, in the other direction, without time consuming restarting of the engine.
Brief Description of the Drawings
The invention will now be described with reference to the drawings wherein:
FIG. 1 shows a side elevation view of a vibratory plate device equipped with an arrangement according to an embodiment of the invention which includes a deadman's handle;
FIG. 2 shows the upper part of the plate control rod with a control handle and the deadman's handle; and,
FIGS. 3 and 4 show a vertical section view through the upper part of the handle with the deadman's handle in the uplifted and dropped positions, respectively.
Description of the Preferred Embodiments of the Invention
FIG. 1 shows the vibratory plate device with its bottom plate 1 and an internal combustion engine 2 to drive the vibratory parts of the plates. the vibratory plate device is maneuvered by a control column 3 mounted on the vibratory plate device. The upper end of the control column is equipped with a control handle 4 and a deadman's handle 5.
The internal combustion engine 2 drives two or more eccentric parts (not shown) so that they counter rotate. The rotating eccentric parts impart a vibratory motion to the plate and a motion forward or backward, depending on the direction of the resultant force generated by the rotating eccentric parts.
In the example shown, the deadman's handle, or the safety handle is pivotally mounted on the control rod 3. The handle 5 has about the same shape and dimensions as the control handle 4 with the difference that the length of the handle 5 parallel to the control handle 4 is shorter than the latter so that it is easier for the operator to grip the control handle 4 and the handle 5 at the same time.
The eccentric parts of the vibratory plate device are driven by the internal combustion engine 2 via a centrifugal clutch. The centrifugal clutch is configured such that it only drives the eccentric parts when the rotational speed (rpm) of the internal combustion engine is above idle speed.
The internal combustion engine's stop, idle and working speed are set according to the invention by the deadman's handle which is pivotally mounted on the control handle. When the deadman's handle is in the dropped position, shown in FIG. 4, the internal combustion engine idles.
The handle 5 is mounted on the control rod by means of two arms 8 extending therefrom. The levers 8 are fixedly attached to a shaft 9 which is pivotally mounted in the control column 3. Also mounted on the shaft 9 is a trip lever 6 which is connected to the fuel control 7 of the engine. When the handle 5 is rotated with respect to the control handle 4, the shaft 9 and with it the trip lever 6 rotates, and the fuel control 7 of the engine is moved simultaneously.
When the handle 5 is lifted up towards the control handle 4, the fuel control 7 is set so the engine runs at working speed. From this position the handle 5 can, by its own weight, fall down to a dropped position that sets the fuel control so the engine idles.
A cam 10 is mounted on the shaft 9 and bears against a spring-loaded support 11 when the handle 5 is in the position shown in FIG. 4. In the embodiment shown, the cam 10 is configured like a clip and it can be adjusted relative to the shaft 9 so that the correct idle speed of the engine can be obtained when the cam 10 bears against the spring-loaded support 11.
If the handle 5 is pressed down even more against the force of the spring-loaded support 11 (stop position), the fuel feed to the engine is interrupted and the engine stops. This arrangement is sufficient for diesel engines. If the engine is a gasoline engine, it is appropriate to have an electric switch in the ignition circuit which bears against the support 11 if the handle 5 is pressed down towards its stop position.
When the vibratory plate device is to be used, it is started in the usual way. Due to its weight, the deadman's handle 5 is in idle position and needs to be lifted up towards the control handle 4 for the eccentric parts to start to rotate. The deadman's handle 5 and the control handle 4 are gripped at the same time by the operator and the plate starts to vibrate and move forward or backward depending on how the eccentric parts are adjusted. As soon as the operator releases the control handle (and the deadman's handle), the deadman's handle swings down due to its own weight, and the engine speed is set to idle speed, and the vibratory plate device stops because the centrifugal clutch no longer connects the engine with the eccentric parts.
It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.