WO2012014229A1

WO2012014229A1 - Foldable type safety stay rod mechanism for 4-point suspended truck cabin

Info

Publication number: WO2012014229A1
Application number: PCT/IN2011/000498
Authority: WO
Inventors: Nilesh Siddeshwar Choudhari
Original assignee: Mahindra Navistar Automotives Limited
Priority date: 2010-07-27
Filing date: 2011-07-28
Publication date: 2012-02-02
Also published as: ZA201300648B; AP2013006727A0

Abstract

The invention relates a foldable type safety stay rod mechanism for trucks with four poi suspended cabin tilting mechanism. The stay rod mechanism comprises a stay rod assembly (3) mounted between the chassis (2) and cabin (1) at one side /both side of said cabin (1 The stay rod assembly (3) consists of top link (12) and bottom link (13) pivotally connected t each other by pin joint (9). A spring loaded latch lever is mounted over the said top bracket (12) near to the said pin joint (9). A pivot bracket (11 ) is connected to the side cabin long member (10) from bottom side. The said top link (12) is connected to the said pivot bracket (11 ) by shock absorbing joint. The said bottom link (13) connected to chassis (2) through th first chassis bracket with ball joint (9). The tilt cylinder (4) for assisting tilting of cabin (1 ) i connected between chassis (2) and pivot bracket (11) at same mounting location as that the said stay rod top link (12). The said cabin (1) is supported by a pair of front ca suspension springs (29) and a pair of rear cab suspension springs (30). The arrangement the cabin front suspension comprises a suspension bracket rear end connected underside cabin (1 ) to pivot bracket (11 ) and the forward end of the suspension bracket (26) is pivotally connected to the cabin mounting bracket (27) which is rigidly connected to chassis ( through the second chassis bracket (28) fixed to the chassis (2).

Description

TITLE:-

FOLDABLE TYPE SAFETY STAY ROD MECHANISM FOR 4-POINT SUSPENDED

TRUCK CABIN

FIELD OF INVENTION:-

The present invention is related to trucks having four point suspended cabin with tilting mechanism. In^'this class of vehicles, the cab is pivotable about a transverse axis from a normal operating position to a forward position where the truck engine is exposed to facilitate servicing. More particularly the present invention is related to the stay rod to hold the cabin in maximum tilt condition to prevent the fall back and fro of the cabin.

BACKGROUND OF THE PRESENT INVENTION:- In the trucks and similar kind of load carrying vehicles having tilting cabin, cabin movement is restricted to vary little in Up-Down direction. In these vehicles, stay rod provided in these vehicles accommodates only vertical motion of cabin. In case of four point suspended cabin trucks, in running condition 3 types of cabin motions are experienced i.e. vertical, fore-aft, and rolling. The present day design of stay rod can not comply with the complex movement of cabin and tend to transfer load to cabin from chassis in vehicle running condition thus not isolate cabin from chassis. The present day trucks with stay rod are, (i) two point suspended cabin trucks i.e. front fixed rubber mount and rear spring and damper mounting, or (ii) four point fixed cabin trucks i.e. all four cab mounts with rubber mounts. Korean patent No. 100774339 discloses a tilting stay rod unit of a cap for a vehicle to perform folding and unfolding operations of stay rods without an additional manipulation by a user during a tilting process of the cap for the vehicle. A tilting stay unit comprises guide plates having a semicircular shape. The guide plates are formed at two sides of a hinge unit Which is formed at an end of a vehicle side stay rod. A guide groove is formed along a circumference of one guide plate. A stopper hole is formed at one side of the guide groove. A cap side stay rod is hinged to the hinge unit of the vehicle side stay rod. A fixation stopper moves along the guide grooves to be fitted into the stopper hole. The fixation stopper is supported by a spring to restrict a tilting radius of a cap.

This prior art patent can not be used for floating cabins and it does not comply with the rolling motion of cabin. This concept has pin joints at its both ends. Proposed design of foldable stay rod uses spherical joint at chassis end to comply with cabin articulation in case of four point suspended cabin

OBJECTIVES OF THE PRESENT INVENTION:-¹ The main objective of the present invention is to provide foldable stay rod to hold the four point of suspended cabin of the vehicle in maximum tilted position.

Another objective of the present invention is to provide foldable stay rod to hold the cabin of the vehicle in maximum tilted position wherein the stay rod uses spherical joint at chassis end to comply with cabin articulation in case of four point suspended cabin.

Another objective of the present invention is to provide foldabie stay rod that prevents of the fall bacK and fro of the four point f suspended cabin.

Still another objective of the present invention is to provide foldabie stay rod for vehicles that isolate cabin from chassis when the cab is in riding position i.e. it does not transfer any load from chassis to cabin in vehicle running condition

ADVANTAGES OF THE PRESENT INVENTION:-

• The present invention does riot hamper cab ride

• The present invention does not create noise/ rattle in vehicle running condition. · This invention is useful in four point suspended cabin trucks wherein a controlled cabin tilt along with safety to workmen without hampering cabin ride is achieved.

• The present invention functions in vehicle running condition as well as Cabin tilt condition as it focuses on use of different end mountings and not locking mechanism.

• The present invention ensures safety requirement as well as gives compliance for cab movement in vehicle running condition STATEMENT OF THE INVENTION:-

Accordingly invention provides a foldable type safety stay rod mechanism for trucks with four point suspended cabin tilting mechanism comprises a stay rod assembly mounted between the chassis and cabin at one side /both side of said cabin; the stay rod assembly consists of top link and bottom link pivotally connected to each other by pin joint; a spring loaded latch lever is mounted over the said top bracket near to the said pin joint; a pivot bracket is connected to the side cabin long member from bottom side; the said top link is connected to the said pivot bracket by shock absorbing joint; the said bottom link connected to chassis through the first chassis bracket with ball joint; the tilt cylinder for assisting tilting of cabin is connected between chassis and pivot bracket at same mounting location as that of the said stay rod top link ; the said cabin is supported by a pair of front cab suspension springs and a pair of rear cab suspension springs; the arrangement of the cabin front suspension comprises a suspension bracket rear end connected underside of cabin to pivot bracket and the forward end of the suspension bracket is pivotally connected to the cabin mounting bracket which is rigidly connected to chassis through the second chassis bracket fixed to the chassis.

According to the preferred embodiment of the invention, a tilt cabin truck has a cabin supported on a chassis by four cabin suspension springs. The stay rod is connected between cabin and chassis with pivot bush at cabin side mounting and spherical bearing at chassis side mounting. When the cabin is in its riding position there is free movement in stay rod to allow movement of the cabin relative to the chassis on its suspension. The rubber bush at cabin side mounting prevents rattling and noise in vehicle running condition. The spherical joint at chassis side mounting isolates cabin and chassis in rolling motion of cabin in vehicle running condition

When the cabin is tilted, the foldable stay rod spring loaded locking mechanism locks and holds the cabin preventing cabin falls back and fro, for passive safety for workmen.

BRIEF DESCRIPTION OF THE FIGURES: -

The following figures will help to have a better understanding of the present invention and its preferred embodiment.

Figure 1 shows schematic view of cabin movement in case of four point suspended cabin.

Figure 2 shows side view of a truck cab and chassis arrangement embodying the invention, the cab being shown in its riding position.

Figure 3 shows side view of a truck cab and chassis arrangement embodying the invention, the cab being shown in its fully tilted position. Figure 4 shows detailed side view of the mechanism, the cab being in the riding position. Position of section A-A at top mounting and section B-B at bottom mounting are shown in this figure. Figure 5 shows detailed sectional view of top mounting of stay rod of the present invention.

Figure 6 shows sectional view of bottom mounting of stay rod showing articulation of cabin in Roll movement

DETAILED DESCRIPTION OF THE PRESENT INVENTION:-

Referring the figures 1-3, the truck comprises of a chassis 2 and a cab 1. The cab 1 is pivotally mounted on the chassis 2 for tilting movement from the riding position illustrated in Figure 2 to a fully tilted position as shown in Figure 3 about a transverse tilting axis 5.

The stay rod assembly 3 consists of top link 12 and bottom link 13 pivotally connected to each other by pin joint 9. The top link 12 is connected to pivot bracket 11 by rubber bush as per details shown in Figure 5. The pivot bracket 1 1 is connected to cabin long member 10 from bottom side. Bottom link 13 connected to chassis 2 through the bracket 6 with spherical bearing 23. Tilt cylinder 4 for assisting tilting of cabin 1 is connected between chassis 2 and pivot bracket 11 at same mounting location 7 as that of stay rod top link 12. In its riding position, the cab 1 is supported by front cab suspension springs 29 and rear cab suspension springs 30. The arrangement of the cab front suspension comprises a suspension bracket 26 connected underside of cabin 1 to pivot bracket 11. The forward end of the suspension bracket 26 is pivotally connected to the cab mounting bracket 27 which is rigidly connected to chassis 2 through bracket 28.

The top link 12 of stay rod is connected to pivot bracket 11 through rubber element to avoid rattling of assembly. Top link 12 is welded to sleeve 14. The rubber bush consists of rubber element 16 molded between outer metal sleeve 15 and inner metal sleeve 17. Innermost sleeve 18 press fitted inside rubber bush inner sleeve 17. The sleeve 18 is made up of poiyurethane and free to rotate about sleeve 19 thus providing rotational movement for top link about sleeve 19. Metal sleeve 19 is rigidly connected to pivot bracket 11 through bolt 21. Additional washer 20 is provided to increase bearing area for bush in lateral movement as explained in figure 5. This joint is shock proof make the mechanism operation very smooth.

Bottom link 13 of stay rod is welded to sleeve 22. The spherical bearing 23 is press fitted in sleeve 22 providing ball joint to bottom link 13. Bottom link assembly is connected to bracket 6 through bolt 24. Additional metal spacer 25 is provided to create necessary clearance between sleeve 22 and mounting bolt 24 as explained in figure 6.

When cabin 1 is in riding condition stay rod 3 is connected between cabin 1 and chassis 2. As cabin is mounted on chassis 2 by suspension springs 29 and 30, when vehicle is in running condition cabin 1 moves vertically 60 mm upwards and downwards (i.e. cabin bump and rebound). Pin joint 9 at top link 12 and bottom link 13 connection allows free movement of links during cabin up-down motion.

In case of roll motion of cabin 1, cabin 1 move about longitudinal axis as shown in Fig 1. The stay rod top mounting 7 moves by 10 degrees in both directions about longitudinal axis with respect to bottom mounting 8. Spherical bearing 23 allows free movement of stay rod in rolling of cabin 1 without any transfer of load from chassis 2 to cabin 1. This isolates the cabin 1 from chassis 2 in all possible cabin positions in vehicle running condition.

In case of cabin 1 tilt, tilt cylinder 4 assists cabin 1 to tilt about pivot 5. Stay rod 3 unfolds about pin joint 9 and links 12 and 13 forms straight line when cabin 1 is fully tilted. The spring loaded latch lever is mounted over top link near to the pin joint 9 as shown in fig. The top portion of the lever has a circular cross section. This lever rotates about the pin. One end of an extension spring is connected to the lever at joint and other end to top link by. This extension spring maintains the position of the lever. Also this lever is used to fold the stay rod. Thus the said spring loaded lever locks the stay rod in tilted condition providing additional safety for workmen under the tilted cabin 1.

Claims

WE CLAIM:-

1. A foldable type safety stay rod mechanism for trucks with four point suspended cabin tilting mechanism comprises a stay rod assembly mounted between the chassis and cabin at one side /both side of said cabin; the stay rod assembly consists of top link and bottom link pivotally connected to each other by pin joint; a spring loaded latch lever is mounted over the said top bracket near to the said pin joint; a pivot bracket is connected to the side cabin long member from bottom side; the said top link is connected to the said pivot bracket by shock absorbing joint; the said bottom link connected to chassis through the first chassis bracket with ball joint; the tilt cylinder for assisting tilting of cabin is connected between chassis and pivot bracket at same mounting location as that of the said stay rod top link ; the said cabin is supported by a pair of front cab suspension springs and a pair of rear cab suspension springs; the arrangement of the cabin front suspension comprises a suspension bracket rear end connected underside of cabin to pivot bracket and the forward end of the suspension bracket is pivotally connected to the cabin mounting bracket which is rigidly connected to chassis through the second chassis bracket fixed to the chassis.

2. A foldable stay rod mechanism for trucks as claimed in claim 1 wherein the said shock absorbing joint comprises a top link connected to the pivot bracket by a welded sleeve, provided with a rubber bush consists of rubber element molded between outer metal sleeve and inner metal sleeve with an Innermost sleeve press fitted inside the said rubber bush inner sleeve, mounted over a metal sleeve fixed the said pivot bracket by a bolt with side washers. A foldable stay rod mechanism for trucks as claimed in claim 2 wherein the said inner most sleeve is made of polyurethane.

A foldable stay rod mechanism for trucks as claimed in claims 1 to 3 wherein the said ball joint comprises a spherical bearing, supported on a bolt with a spacer in between fixed to the said first chassis bracket, press fitted in the welded sleeve to the bottom link of said stay rod.

A foldable stay rod mechanism for trucks as claimed in claims 1 to 4 wherein the said spring loaded lever, having circular cross section top portion rotate able about the pin, one end of an extension spring is connected to the lever at joint and other end to top link.