CREEP SPEED LEVER MECHANISM FOR P&C CRANE
Field of the present invention:
The present invention is generally related to assembly of a novel creep speed lever mechanism with the existing drive-line assembly of a Pick and Carry (P&C) crane and its method of operation thereof, primarily towards reducing the first speed of a tyre based P&C crane. Creep speed lever, as a main component of the proposed mechanism herein, is suitably installed in the driver's/operator's cabin, wherein the driver operates the said lever by moving it reverse-forward linearly towards reducing/creeping the speed of the crane, preferably towards achieving the first speed around 3Km/h and attaining the preferred engine rated rpmat 1400.
Background and Object of the present invention:
The power transmission system of load carrying vehicles like pick and carry crane, other such mobile construction equipments, and even tractors are so designed and provisioned that they are suitable for moving smoothly at low speed, especially in loaded conditions and even in critical road conditions. For the purpose of safe movement of a crane, particularly a tyre based Pick and Carry crane (P&C crane), more particularly a loaded P&C crane, it is important that the crane starts moving with considerably slow initial speed in comparison to other moving vehicles. Engine rpm plays vital role in regulating the vehicle's
speed, wherein the said vehicle speed also depends on various power transmission related factors like the ring gear and pinion gear ratio, the height of the tires (diameter from ground to top of the tire while mounted on the vehicle) and the transmission final gear ratio etc. for various transmission conditions, such as auto or AOD or manual or 5 speed etc. The higher the RGP ratio, the lower the top end speed but faster acceleration therein and more pulling power. The same is true for the transmission final gear ratio. Higher the engine rpm means higher the engine's crankshaft rotation and therefore higher will be the speed of the vehicle.
Usually, as a matter of practice, the first speed of a crane is maintained at lowest possible value, which mainly depends on the load capacity of the crane, namely of 10 ton maximum capacity or 12 ton or 14 ton or 16 ton or 20 ton or 30 ton and so on. Therefore to achieve such low/reduced first speed, a new optimized suitable drive line assembly for a crane of specific load capacity requires be designing and manufacturing. Such designing and manufacturing of a new drive line assembly for a crane, mainly guided by its load capacity and safety criteria of the country/territory, is practically not possible every time.
In case of one exemplary P&C crane of the applicant herein, which employs a conventional drive line assembly, being conventionally installed in P&C cranes according to road safety parameters applicable in India, wherein the engine rated rpm is 2200, the crane's lowest first speed obtained is 5.8Km/h & its max speed is 38Km/h. First speed of this exemplary P&C crane is high for laden condition and it is not safe to handle heavy loads on this speed. To overcome such situation of high first
speed, it becomes vital challenge to reduce the said first speed preferably upto 3Km/h and achieving the engine rated rpm preferably upto 1400; especially without making any alteration in the said power transmission system being installed conventionally in such PnC cranes.
There are a few creep lever mechanisms available for various other applications, not concerned with the present matter. For instance certain digital or electronic device/sensor based speed creeping mechanism is being used in certain type of Japanese tractors. One another backhoe creep lever mechanism for excavating vehicle is known (US 4,869,337), which is particularly related to backhoe operation, wherein the creep mechanism means includes a creep lever and the said creep linkage means therein, mainly involves the coupling of the creep lever to the hydraulic pump through the foot pedal. These known arts do not deal with the present particular technical problem of creeping/reducing the vehicle's first speed herein.
As it has already been proposed herein above, the present invention perfectly deals with aforementioned technical complication, wherein the present proposed invention particularly relates to reducing/creeping the first speed as well as the engine rpm of the P&C crane, mainly by suitable incorporation of "creep speed lever mechanism" with the conventional drive line assembly being used therein, preferably towards achieving the first speed around 3Km/h and attaining the preferred engine rated rpm at 1400.
Prime object of the present invention is to propose a creep speed lever mechanism for reducing/creeping the first speed of a vehicle, wherein the said
creep speed lever mechanism is particularly customized for reducing/creeping the first speed of a tyre based P&C crane.
Another prime object of the present invention is to propose method of suitable incorporation of the said proposed creep speed lever mechanism into the drive line assembly of the vehicle, particularly into the drive line assembly of a P&C crane, wherein the creep speed lever of the said proposed mechanism is connected to the accelerator pedal using a suitable cable; wherein the said accelerator pedal is duly connected to engine through its accelerator cable.
Another prime object of the present invention is to propose a suitable installation of the creep speed lever in the driver's/operator's cabin of a P&C crane; particularly at left side of the driver's/operator's seat; and more particularly at such a position in the driver's/operator's cabin of the P&C crane that the drive can easily hand operate the said lever.
Another object of the present invention is to propose customized mounting of the said creep speed lever in the driver's/operator's cabin with the help of a mounting bracket (throttle bracket) comprising of certain mechanical stopper(s), wherein the movement of said creep speed lever is controlled with the help of said mechanical stopper.
Another object of the present invention is to propose the method of operation/functioning of said creep speed lever mechanism; wherein the said
mechanism particularly becomes functional towards reducing/creeping of the first speed of a crane, once the engine of the vehicle gets started and the driver, seating on his seat in the driver's/operator's cabin of the P&C crane, hand operates the creep speed lever in reverse-forward direction linearly to activate/deactivate the first speed reducing/creeping action of the proposed creep speed lever mechanism.
Statement of the present invention:
The present invention is intended to propose a novel creep speed lever mechanism, preferably to be applicable in the vehicle like P&C crane, mainly to reduce/creep the first speed of the said vehicle; wherein it is further intended to propose:
• a creep speed lever mechanism for reducing/creeping the first speed of a vehicle, wherein the said creep speed lever mechanism is particularly customized for reducing/creeping the first speed of a tyre based P&C crane;
• method of suitable incorporation of the said proposed creep speed lever mechanism into the drive line assembly of the vehicle, particularly into the drive line assembly of a P&C crane, wherein the creep speed lever of the said proposed mechanism is connected to the accelerator pedal using a suitable cable; wherein the said accelerator pedal is duly connected to engine through its accelerator cable;
• suitable installation of the creep speed lever in the driver's/operator's cabin of a P&C crane; particularly at left side of the driver's/operator's seat; and more particularly at such a position in the driver's/operator's cabin of the P&C crane that the drive can easily hand operate the said lever;
• customized mounting of the said creep speed lever in the driver's/operator's cabin with the help of a mounting bracket (throttle bracket) comprising of certain mechanical stopper(s), wherein the movement of said creep speed lever is controlled with the help of said mechanical stopper;
• Another object of the present invention is to propose the method of operation/functioning of said creep speed lever mechanism; wherein the said mechanism particularly becomes functional towards reducing/creeping of the first speed of a crane, once the engine of the vehicle gets started and the driver, seating on his seat in the driver's/operator's cabin of the P&C crane, hand operates the creep speed lever in reverse-forward direction linearly to activate/deactivate the first speed reducing/creeping action of the proposed creep speed lever mechanism.
Summary of the present invention:
The present invention is primarily related to a new creep speed lever mechanism to regulate the first speed of a vehicle, particularly a P&C crane,
wherein the said mechanism, duly incorporated with the existing drive line assembly by connecting the creep speed lever assy to the main throttle assembly of the engine, mainly by connecting the said creep speed lever assy to the accelerator pedal using suitable connecting cable therein, substantially reduces/creeps the first speed of the said crane upto the desired level, preferably up to 3Km. per hour.
When a P&C crane, particularly in its laden condition, starts moving, its speed acceleration should be so that the normal first speed of the crane should be considerably very low. Such smooth and slow acceleration becomes very important because of safety reasons associated with the movement of a heavy and loaded vehicle like P&C crane, preferably on a normal road traffic condition and more preferably in a critical site with unfriendly conditions towards movement of such heavy crane.
Therefore, to avoid any safety related issue due to high first speed of a tyre based P&C crane or any such heavy vehicle inter alia, the throttle assembly of the crane's engine is incorporated with an additional mechanism towards controlling the crane's initial acceleration, mainly by regulating the engine's rpm and bringing it upto such a level that the crane achieves the safest and desired first speed.
According to the proposed mechanism herein, the existing accelerator pedal of the crane, which is already connected to engine and the drive line
therein with the help of accelerator cable, is connected to the proposed creep speed lever (a hand throttle assy herein) with the help of suitable cable therein. The creep speed lever, termed is mounted on a uniquely designed mounting bracket, termed as throttle bracket, which is provisioned for customized assembly of the said lever and its mechanical functioning thereof. The said mounting bracket is fixed/rigidly screwed on the base surface of the driver's/operator's cabin and its preferred position is in the left hand side of the driver's/operator's seat, preferably within the comfortable reach of the driver.
The crane driver, seating on his seat inside the driver's/operator's cabin of the crane, holds the said creep speed lever in his left hand and moves it in reverse or forward direction, whichever is provisioned therein, and activates the functioning of the creep speed lever towards reducing/creeping the first speed of the crane. Putting the creep speed lever in the active position, the driver operates the accelerator pedal towards accelerating the crane and initiating its movement with its desired creeped/reduced first speed therein. The reverse-forward linear movement of the creep speed lever is controlled by the mechanical stopper provisioned in the said throttle bracket, engaged with the said creep speed lever therein.
Description of the invention with the help of drawings:
The invention already proposed herein in more comprehensive manner, following drawings are referred:
Figure 1: Schematic view of the creep speed lever assembly;
Figure 2: Figure 2 represents schematic isomeric view of the main body of throttle bracket, provisioned for mounting the said creep speed lever, showing its preferred structural features, namely installation base, lever mounting platform and the mechanical stopper.
Figure 3: Complete schematic side view of the creep speed lever positioned in the left hand side of the driver's/operator's seat and the incorporation of said lever assy with accelerator pedal and ultimately with the drive-line therein.
In one exemplary embodiment of a P&C crane, its first speed 5.8Km/h & max speed 38Km/h. Engine rated rpm is 2200. First speed is high for laden condition and it is not safe to handle heavy loads on this speed. Therefore the purpose of using the proposed creep speed lever in this PnC crane is to have preferable first speed 3 Km/h in laden conditions and for reducing the engine rated rpm preferably upto 1400. Creep speed lever is assembled inside the cabin with the help of mounting bkt. Drivers will operator it by moving lever reverse-forward linearly. Lever movement is controlled through the mechanical stopper, which is the essential part of the throttle bracket and is engaged with the said lever in customized manner. Lever is connected with accelerator pedal with the help of a cable. It will provide an option of creep speeds to operators. Main speeds will be provided by accelerator pedal.
The Figure 1 represents creep speed lever assembly or the hand throttle assy, wherein the creep speed lever 1 is provisioned with the lever holder 2. The said lever 1,
at its base embodiment 4, is provisioned for customized assembling and mounted on throttle bracket 3, mainly on the lever mounting platform 8 therein and gets duly engaged with the mechanical stopper 9, provisioned in said throttle bracket 3. Thus the reverse-forward linear movement of said creep speed lever 1 gets mechanically operated by the operator/driver.
The main body of the throttle bracket 3, as schematically depicted in figure 2, mainly comprises of structural features like the installation base 5, the creep speed lever assembly holding segment 7, the lever mounting platform 8 and the mechanical stopper 9. The installation base 5 of the said throttle bracket 3 is either fixed using certain nut-bolt/stud(s) 6 on the suitable surface, preferably on the bottom plate in the driver's cabin of the crane, or it is optionally welded & fixed thereto. The mounting platform 8, at its horizontal base section 12 is primarily placed on the segment 7, while its vertical plate 11 holds the mechanical bracket 9 therein. The creep speed lever 1, at its base embodiment 4 is suitably mounted on the vertical plate 11 of the mounting platform 8, preferably with the help of certain studs or nut-bolts at position(s) 10 thereof. The Mechanical stopper provision 9 is duly engaged with the base segment 4 of the creep speed lever 1 towards controlling its movement.
The creep speed lever is installed preferably at a comfortable position at left hand side of the driver's seat 15 in the driver's cabin 16 of the crane, preferably on the bottom surface of said cabin 16, as schematically depicted in Figure 3 herein. The main schematic embodiment of the creep speed lever assembly 14 is highlighted in the inset box, wherein the provision for controlling the movement of said lever 1 is depicted as mechanical stopper 9. The said creep speed lever assembly 14 is mounted on throttle
bracket 3 and a connecting cable 18 connects the said creep speed lever assembly 14 to the main accelerator pedal 17, as schematically depicted herein, mainly at connecting junction 19. Said connecting junction 19 of the accelerator pedal 17 is further connected to accelerator cable 20, which connects the said accelerator pedal 17 to engine and the drive-line of the crane. Said creep speed lever assembly 14, duly incorporated with the existing engine and its power transmission system, functions in perfect co-ordination to the main accelerator pedal 17.
Thus the present invention simply provides a mechanism to mechanically reduce/creep and very conveniently control the first speed of a vehicle, namely a pick and carry crane which travels with heavy load. Most important feature of the proposed technology herein is that, it perfectly gets incorporated with the existing drive-line assembly of a vehicle and without requiring any alteration & modification in the existing engine and the power transmission system therein, it acts as an additional assessor for reducing/creeping the first speed of the vehicle.
Scope of the invention:
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present invention as defined.

We claim:
1. The creep speed lever mechanism for a tyre based pick and carry (P&C) crane, wherein the said creep speed lever mechanism primarily comprising of a creep speed lever assy (14), a suitable mounting bracket as the throttle bracket (3) and the connecting cable (18); wherein the said creep speed lever mechanism is characterized by installation of the said creep speed lever assy (14) in the driver's cabin (16) and its mechanical operation by the driver/operator towards reducing/creeping and controlling the first speed of the said crane.
2. The creep speed lever mechanism, as claimed in claim 1, is characterized by its incorporation into the existing engine and drive-line assembly of a vehicle, preferably through the accelerator pedal (17), particularly a tyre based heavy vehicle, and more particularly a tyre based pick and carry (P&C) crane; wherein the said creep speed lever assembly (14) is mainly connected to the accelerator pedal (17).
3. The creep speed lever mechanism, as claimed in claim 1, is characterized by reducing/creeping the first speed of the vehicle/crane, preferably reducing the engine rated rpm.
4. The creep speed lever mechanism, as claimed in claim 1, is characterized by the mechanical operation of the said mechanism, wherein the
driver/operator, preferably seating on his seat (15), moves the creep speed lever (1) in reverse-forward linearly towards activating/deactivating the functioning of the said creep speed lever mechanism.
5. The creep speed lever mechanism, as claimed in claim 1, wherein the throttle bracket (3) comprises of the mechanical stopper (9), which is duly engaged with the creep speed lever (1), at its base embodiment (4), and wherein said mechanical stopper (9) is responsible for controlling the mechanical reverse-forward linear movement of the said lever (1).
6. The creep speed lever mechanism, as claimed in claim 1, wherein the creep speed lever assy (14) of the said proposed mechanism is connected to the accelerator pedal (17) using a suitable connecting cable (18) preferably at the connecting junction (19); wherein the said accelerator pedal (17) is duly connected to engine/drive-line through its accelerator cable (20).
7. The creep speed lever mechanism, as claimed in claim 1, wherein the creep speed lever assy (14) is installed in the driver's/operator's cabin (16) of a P&C crane; particularly at left side of the driver's/operator's seat (15); and more particularly at such a position in the driver's/operator's cabin (16) of the P&C crane that the drive can easily hand operate the said lever (1).
8. The creep speed lever mechanism, as claimed in claim 1, wherein the said mechanism is characterized in one exemplary embodiment of a pick and carry crane, wherein it reduces the first speed of the said crane upto 3KM. per hour at the preferable engine rated rpm 1400.