WO2017003386A1

WO2017003386A1 - Labor-saving truck tailgate device

Info

Publication number: WO2017003386A1
Application number: PCT/TH2016/000056
Authority: WO
Inventors: Chidchanok HONGLAWAN
Original assignee: Honglawan Chidchanok
Priority date: 2015-07-02
Filing date: 2016-06-20
Publication date: 2017-01-05

Abstract

A labor-saving truck tailgate device according to this invention comprises at least three main components: a tailgate bracket a coiled spring, and a spring-end holding or supporting unit wherein one end of the spring is connectable to the tailgate bracket so in order to rotate in the same manner as the degree of rotation of the truck tailgate during its opening. At the same time, the other end of the spring is anchored or held to the spring-end holding or supporting unit which is connectable to the truck body so as the tailgate is opening, one end of the spring which is held to the bracket is also rotated in the same direction as the tailgate; whereas the other end of the spring, which is anchored to the spring-end holding or supporting unit, absorbs tension or strain from such rotation. Such tension helps to reduce the shock creates by the drop of tailgate weight during opening and also to labor-save user during its closing.

Description

TITLE OF THE INVENTION

LABOR-SAVING TRUCK TAILGATE DEVICE

FIELD OF THE INVENTION

The field of engineering in relation to a labor-saving truck tailgate device. BACKGROUND OF THE INVENTION

A truck or a pickup truck with the size of at least 1 ton is characterized by a tailgate connectable to the truck body and a locking device to lock said tailgate to the body. Figure 1 illustrates one embodiment of the truck tailgate during closing wherein the tailgate ( 1 1 1 ) is connected to the truck body (121 ).

Figure 2 illustrates one embodiment of the tailgate during opening wherein the internal view shows the tailgate ( 1 1 1 ) during opening from the truck body and the tailgate ( 1 1 1 ) is connected to a truck part ( 121 ) with rotational points (2, 3) dictating by slings or a hinges (4, 5) on both sides of the tailgate ( 1 1 1 ). At one end of each sling or hinge (4, 5) is connectable to the truck body ( 121 ) and the other end of said sling or hinge is connectable to the tailgate d 1 1 ). The sling or hinge (4, 5) may have different characteristics depending on the truck or car models, but shall support the tailgate to swing open up to 90 ⁰ angle.

During operation, the tailgate ( 1 1 1 ) may be dropped abruptly if the user let the tailgate drop freely. This can be dangerous for users who are within the dropping radius At the same time, the act of closing the tailgate ( 1 1 1 ) and locking to the truck body ( 121 ) may require large amount of physical force to lift the heavy tailgate ( 1 1 1 ) up.

Further, there have been attempts to create mechanics and methods for labor-saving of the truck tailgates during opening using various materials such as torsion bar and gas spring wherein the material used is dependent of the type of truck and inventing technique used by the related inventor. Another attempt to labor-save at opening and closing is by using the electric motor wherein said invention further requires a motor which wastes more energy and is costly to maintain.

When referring to a Thai patent application 150700231 1 under the title: labor-saving tailgate hinge" which utilizes a coiled spring to create a strain or tension via the rotational force of the coiled spring to reduce the shock during opening of the tailgate and, at the same time, the accumulating strain or tension inside the spring gets converted into the recoil force during closing of the tailgate; thus, labor-save the tailgate lifting and closing tasks Nevertheless, this invention still not agile enough to adapt or adjust the spring to best-fit certain labor-saving task, but merely to adjust the size or number of springs to certain hinges. The labor-saving truck tailgate device according to this invention can solve the issue as stated above by ensuring effective labor-saving of the tailgate during its opening and closing by means of utilizing a coiled spring to withhold or load the weight of the rotating tailgate during its opening and to labor-save during its closing due to the accumulating strain in the coil acting as a push force. Further, the present invention can be adjusted or modified to enable different labor-saving situations.

SUMMARY OF THE INVENTION

A labor-saving truck tailgate device according to this invention comprises a bracket connectable to a tailgate, a coiled spring, and a spring-end holding or supporting unit on the spring s end wherein one end of the coiled spring connects to the bracket to the tailgate, and the other end is connectable or held on to the spring-end holding or supporting unit. The spring-end holding or supporting unit is connectable to the truck body to withstand one end of the coiled spring while said holding and supporting unit further comprises a brace to hold one end of the spring to a preferable angle in order to increase or reduce the spring s inner tension or force.

The objectives of this invention are to create a labour-saving truck tailgate device to labor-save the tailgate during opening and closing tasks on a truck or a pickup truck wherein the invented device takes the advantage of the strain that has been created by rotation of the coiled spring to reduce the shock from the tailgate' s weight during opening and closing and to enable the modification of the device for different labor-saving requirements on various pickup trucks with tailgates.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 illustrates one embodiment of the truck tailgate during closing;

Figure 2 illustrates one embodiment of the truck tailgate during opening;

Figure 3 illustrates one embodiment of the tailgate anchoring bracket;

Figure 4 illustrates one embodiment of the drilled hole of the truck and the drilled hole of the bracket;

Figure 5 illustrates a central plane of a stud and the rotation point of the tailgate;

Figure 6 illustrates one method of connecting a metal plate with nuts to the inner side of the tailgate;

Figure 7 illustrates one embodiment of the coiled spring according to this invention;

Figure 8 illustrates one embodiment of the spring-end holding or supporting unit;

Figure 9 illustrates one embodiment of the spring-end holding or supporting unit;

Figure 10 illustrates one embodiment of the spring-end holding or supporting unit;

Figure 1 1 illustrates one embodiment of the spring-end holding or supporting unit and its usage;

Figure 12 illustrates one embodiment of the method of assembling the coiled spring to the bracket for connecting to the tailgate;

Figure 13 illustrates one view from under the truck;

Figure 14 illustrates one embodiment of the anchoring bracket comprising the coiled spring once connected to the tailgate;

Figure 15 illustrates one method of connecting the spring end to the spring-end holding or supporting unit;

Figure 16 illustrates one embodiment of the modification of the spring- end holding or supporting unit according to this invention; and

Figure 17 illustrates one embodiment of the labor-saving truck tailgate device according to this invention during operation;

DETAILED DESCRIPTION OF THE INVENTION A labor- saving truck tailgate device according to this invention comprises 3 main components: a tailgate anchoring bracket (301 ), a coiled spring (302), and a spring-end holding or supporting unit (51 ) wherein the bracket (301 ) acts as a hinge, the coiled spring (302) acts as a labor-saver, and the spring-end holding or supporting unit ( 51 ) acts as a spring force regulator. The coiled spring can be connected to a formed metal sheet for connecting to the tailgate anchoring bracket with a stud wherein the other end of the coiled spring is anchored or fixed to the holding and supporting unit which is connected to the truck body.

For the tailgate ( 1 1 1 ) of the pickup truck of at least 1 ton, the two rotational points on both sides of the tailgate (1 1 1 ) contain a gap between the tailgate ( 1 1 1 ) and the lower edge of the truck body (121 ). Thus, the labor-saving truck tailgate device shall be installed between this gap. Normally, the tailgate requires 1 set of device, but 2 sets of such device can also be used on 1 tailgate ( 1 1 1 ) to reduce the sizes of the hinge and coiled spring (302) within the labor-saving truck tailgate device. Nevertheless, for any truck with a large enough gap between the tailgate ( 1 1 1 ) and the truck body ( 121 ), the size of the device can be increased and the spring can be bigger to improve strength.

Figure 3 illustrates one embodiment of the tailgate anchoring bracket wherein the bracket (301 ) comprises a formed metal sheet (6) for connecting to the tailgate ( 1 1 1 ) and a stud

(7) for assembling the coiled spring (302). The formed metal sheet (6) for connecting to the tailgate (1 1 1 ) is characterized by an angled metal sheet comprises at least two holes ( 10, 1 1 ) for connecting the bracket (301 ) to the tailgate ( 1 1 1 ) and one part of the spring-end insertion unit or a spring-insertion and anchoring pipe (32). One end of the coiled spring ( 16) is inserted through the spring-insertion and anchoring pipe (32) whereas another part of the angled metal sheet comprises at least one stud insertion unit or a stud- insertion pipe of the bracket (34, 35), but preferably 2 pipes (34, 35). The stud (7) is then inserted through said stud-insertion pipes (34, 35) to be set as coiled spring connecting stud (302) to enable the spring to act as labor-saver.

Figure 4 illustrates one embodiment of the holes of the truck and of the bracket wherein the bracket (301 ) is specifically invented to be connected to the tailgate ( 1 1 1 ) using the same hole positions (8, 9) to prevent any further drilling on the tailgate ( 1 1 1 ) and so the bracket (301 ) comprises a set of holes (10, 1 1 ) on the same position as the tailgate holes (8, 9).

Figure 5 illustrates a central plane of the stud with the rotation points of the tailgate wherein the center of the stud ( 12) is on the same position as the center of the rotation points of the tailgate (13, 14).

Figure 6 illustrates one embodiment of the method of using a nut welded metal sheet to connect to the inner side of the tailgate ( 1 1 1 ) wherein even though original holes of tailgate (8,

9) did not contain a set of nuts to connect inside, a set of pop nuts can be shot and fix the bolts externally in order to connect the bracket (301 ) to the tailgate (1 1 1 ). In the case where the tailgate cover can be taken off, a set of hands be can employed to connect the metal sheet (14) from the inner side of the tailgate (1 1 1 ) to tighten the bolts and the bracket (301 ) as well

Figure 7 illustrates one embodiment of the coiled spring according to this invention wherein the coiled spring (302) comprising 3 components as follows: a coiled spring end (16), a spring body (33) and the other coiled spring end ( 17) wherein the coiled spring is characterized by a set of coils or loops which forms the spring body (33) and wherein one end is elongated for inserting into the bracket (301 ). The elongated end is preferably comprising at least one angled edge with one extending end in order to connect to or inserted inside the tailgate bracket (301 ).

One end of the coiled spring ( 16) is located in the same direction as the core of the spring (33) whereas the other end is elongated for inserting and fixing into the spring-end holding or supporting unit (51 ). The elongated end preferably comprising one angled edge wherein the end is connected into the spring-end holding or supporting unit. The other end of the coiled spring

(17) which is positioned in perpendicular to the core of the spring (33) preferably comprising the elongated end making at least 2 angles as illustrated in Figure 7.

One end of the coiled spring ( 16) is inserted and fixed to the tailgate bracket ( 301 ) whereas the other end ( 1 7) is fixed to the spring-end holding or supporting unit (51 ) which is then connected to the truck body ( 121 ) by which the spring end ( 17) is inserted through the tailgate (1 1 1 ) and the lower edge of the truck (121 ), providing that the size and hinge angle make a good fit to the truck body ( 121 ) for the convenience of assembling with the spring-end holding or supporting unit (51 . Nevertheless, the means for finding suitable sizes and numbers of coils for tailgates of different types of car models can be calculated from a common spring manufacturing method, which can be based on a conventional theory or through trial and error process.

Figure 8 shows one embodiment of the spring-end holding or supporting unit wherein the unit (51 ) comprises two main components: a truck connecting component (81 ) and a spring- end anchoring component (82) which are present in two formed metal sheets, namely an upper formed metal sheet (18) for connecting to the truck body (121 > and the lower formed metal sheet (20) for connecting one spring end ( 17) of the coiled spring (302) wherein the upper formed metal sheet (18) and lower formed metal sheet (20) are connected together by a stud (28) with retaining ring (29).

For the spring-end holding unit (51 ):

The truck connecting component (81 ) comprising at least one upper formed metal sheet ( 18) characterized by one end connectable to the truck body through a set of defined positions which may or may not contain a concaved portion. One embodiment containing a concaved portion on the lower edge of the truck body with an edge (39) wherein a nut ( 19) is fixed to and penetrated by drilling (180) for putting bolts (30) into to fix the spring-end holding unit (51 ) to the truck body (121 ). Another embodiment does not contain the concaved portion as illustrated in Figure 9 and where one end is connectable to the lower formed metal sheet (20) by a stud (28) through both metal (1 8, 20) and is fixed with stud (28) and retaining ring (29).

The spring-end holding or supporting component (82) comprising the lower formed metal sheet (20) which further comprises a brace (21 ) for adjusting the spring angle of the coiled spring (302) in order to increase or reduce the spring force as deemed appropriate for a certain task. The lower formed metal sheet (20) is characterized by one end which is connectable to an upper formed metal sheet ( 18) and the other end which further comprises the brace ( 21 ) for acting as the spring- end holding or supporting unit ( 5 1 ) wherein one portion is welded with at least 2 bolts (22, 23) for tightening at least 2 nuts (24, 25) on the brace (2 l i which contains at least 2 holes for fixing the spring end ( 17) of the coiled spring (302). The other end of the lower formed metal sheet (20) comprising at least 1 nut (26) for welding with drilled hole (200) for tightening bolt (27); thereby, the spring angle can be adjusted to increase or reduce the spring force as deemed appropriate.

Figure 9 illustrates one example of the spring-end holding unit whereby said unit (51 ) can be designed in various forms depending on the designs of the back end of the truck by which said unit (51 ) will be installed. The spring end ( 17) or the coiled spring (302) according to

Figure 9 is, thus, an example of the anchoring unit (51 ) which is specifically designed for the specific truck on that location.

Figure 10 displays another example of the spring-end supporting unit ( 5b comprising two main components: one component for connecting to the truck body ( 81 ) and the second component for supporting the spring end (82) wherein the design depends on the characteristics of the back end of the truck at the spring holding position by one end of the spring ( 17) of the coiled spring (302).

For the spring-end supporting unit (5 1 ):

One example taken from the back and bottom side of the truck of the spring- end anchoring position provides that the unit (51 ) is characterized by

One component for connecting to the truck body comprising at least 2 upper formed metal sheets (18) wherein each can fit the truck body (121 )with or without a concaved portion. In one embodiment with concaved portion to support the truck body ( 121 ) provides that there is at least 1 holding device such as nut ( 19) and bolt (30) and at one end provides that that one spring end d 7) is touched upon to act as a labor-saver for the coiled spring (302) as illustrated in Figure 1 1.

Figure 1 1 illustrates one embodiment of the spring-end supporting unit and its uses by means of having said spring-end supporting unit (51 ) holding or connecting to the truck body ( 121 ) with the upper formed metal sheet ( 1 8) and wherein one end for supporting the spring extends beyond the edge of the truck (121 ), which is the portion of the lower formed metal sheet (20) to support the other end of the coiled spring ( 17) of the coiled spring (302) in order to withstand the force created by the spring rotation during opening to the tailgate ( 1 1 1 ). One end ( 16) of the coiled spring is still fixed to the tailgate anchoring bracket (301 ) by the anchoring pipe (32) wherein the pipe is a supporting portion for the coiled spring end of the bracket (301 ). In the act of using the spring-end supporting unit (51 ), the spring force or the coiled spring (302) is still similar to the spring-end holding unit (51 ), but which can also modify the force of the coiled spring (302) as indicated in Figure 16.

Figure 12 illustrates one embodiment of the coiled spring and bracket assembly wherein the one end ( 16) of the coiled spring (302) is inserted into the anchoring pipe (32) which is portion of the spring end supporting bracket (301 ) and the spring body (33) is adjusted so that it is centrally aligned with the pipe of bracket (34, 35). A stud (7) is inserted into the stud supporting pipe (34, 35) and the spring body (33). The stud (7) is then locked with a supporting ring (37) and an outer retaining ring (38).

Figure 13 illustrates a view from under the truck wherein the illustration shows how the spring-end holding unit is connected to the truck body in one embodiment

A method of assembling the spring-end holding unit to the truck body

Taking the tailgate bracket (301 ) with assembled coiled spring (302) and connecting to the tailgate ( 1 1 1 ) at the spot of installation to identify the position of the spring end to be held to the spring-end holding unit ( 51 ) as illustrated in Figure 1 or supporting unit as illustrated in Figure 1 1 ; that is, one end ( 17) of the coiled spring (302). Further the spring-end holding or supporting unit (5 1 ) is then connected to the lateral side of the metal under the truck which is to be used for fixing ( 39) the bolt ( 30) to the upper formed metal sheet ( 18) and tightening with nut ( 19) to lock in the bolt (30) to its position as illustrated in Figure 13 or Figure 1 1.

Figure 14 indicates one embodiment of the tailgate bracket with the coiled spring connecting to the tailgate.

A method of assembling the tailgate bracket

Assembling the tailgate bracket (301 ) with the coiled spring (302) to the tailgate ( 1 1 1 ) with a connecting tool chosen from bolt (M8) for tightening with pop nut. Some truck models may be able to insert M8 nut inside the tailgate ( 1 1 1 ) without the need of using a shot of pop nut.

A method of assembling the spring end to the spring-end holding unit

Inserting one end ( 17) of the coiled spring (302) through the spring holding channel under the unit and connecting brace (21 ) with nuts (24, 25 ) to tighten one end ( 17) to the spring-end holding unit (51 ) in accordance with Figures 13 and 15. Figure 16 also represents one embodiment of the modified spring force of the spring-end holding unit according to this invention.

A method of modifying the spring force to suit its usage

Tightening the bolt ( 27) via the lower formed metal sheet to support or lean to the lower portion of the upper formed metal sheet ( 18) of the spring-end holding unit (51 ). When tightening the bolt (27) clockwise, the tip of the bolt (27) shall lean on the lower portion of the upper formed metal sheet ( 18), causing the lower formed metal sheet (20) of the spring-end holding unit ( 51 ) to move away from the upper formed metal sheet (18) of the unit (51 and to change the spring angle accordingly. The angle shall induce tension in the coiled spring (302) to prevent the shock due to the opening of the tailgate ( 1 1 1 ) and shall provide a pushing force during closing motion of the tailgate (1 1 1 ). On the other hand, if the bolt (27) is moved counter-clockwise the force shall be the opposite.

Figure 17 illustrates one embodiment of the usage of the labor-saving truck tailgate device according to this invention by showing the functioning of the device during opening of the tailgate ( 1 1 1 ) so that the bracket (301 ) rotates in the same direction as the tailgate ( 1 1 1 ) and wherein one end ( 16) of the coiled spring is also rotating, causing the twisting of the coiled spring (302). At the same time, the other end ( 17) of the coiled spring is fixed to the spring-end holding unit (51 ) and has no movement even during the opening of the tailgate ( 1 1 1 ), thus, causing tension or strain inside the coiled spring (302) to withhold the weight of the tailgate ( 1 1 1 ) which is rotating downward. The accumulating strain also acts as a labor-saver during closing of the tailgate (1 1 l ) to the truck body ( 121 ).

The labor-saving truck tailgate device according to this invention can be adjusted or modified in accordance with the task by means of switching the size of the spring based on the weight of the truck tailgate or based on its users tasks and preference.

Claims

1 . A labor-saving truck tailgate device comprises:

a tailgate bracket comprises a formed metal sheet for connecting to the tailgate and a stud for serving as a core for assembling a coiled spring,

- a coiled spring comprises a spring body, a first spring-end for inserting into the tailgate bracket, and a second spring-end for connecting to or touching a spring-end holding or supporting unit,

a spring- end holding or supporting unit comprises an upper formed metal for connecting to the truck body and a lower formed metal for holding or supporting the second spring-end of the coiled spring, and wherein the coiled spring is assembled together with the formed metal sheet for connecting to the tailgate bracket by the stud and wherein one end of the coiled spring is connecting to or touching on the spring- end holding or supporting unit which is connected to the truck body.

2. The labor-saving truck tailgate device according to claim 1 wherein the formed metal sheet is angled for fitting to the truck tailgate and the truck body.

3. The labor-saving truck tailgate device according to any of claims 1 or 2 wherein one portion of the formed metal sheet comprising at least 2 holes for connecting or assembling with the tailgate bracket.

4. The labor-saving truck tailgate device according to any of claims 1 or 2 wherein the formed metal sheet further comprises at least one spring-end supporting component which is a spring anchoring pipe

5. The labor-saving truck tailgate device according to any of claims 1 or 2 wherein the formed metal sheet further comprises at least one stud supporting component which is a stud insertion pipe.

6. The labor-saving truck tailgate device according to claim 5 wherein the formed metal sheet comprises of two the stud insertion pipes

7. The labor-saving truck tailgate device according to claim 1 wherein a pop nut is used to fix the tailgate bracket to the tailgate and the bolt is then used to tighten the connection from the exterior side or a hand is manually inserted to assemble the nut- welded metal sheet from inside the truck cover to tighten the bolt.

8. The labor-saving truck tailgate device according to claim 1 wherein one end of the coiled spring is elongated and is used for inserting into or connecting with the tailgate bracket and that said end has at least one angled edge.

9. The labor-saving truck tailgate device according to any of claims 1 or 8 wherein one end of the coiled spring is positioned on the same direction as the core of the spring body.

10. The labor-saving truck tailgate device according to claim 1 wherein one end of the coiled spring is elongated for inserting into or connecting with the spring-end holding unit or leaning onto the spring-end supporting unit wherein said end has at least one angled edge.

1 1. The labor-saving truck tailgate device according to claim 10 wherein another elongated end of the coiled spring making two angles to one another

12. The labor-saving truck tailgate device according to any of claims 1 , 10, or 1 1 wherein one end of the coiled spring is positioned perpendicularly to the core of the spring body.

13. The labor-saving truck tailgate device according to claim 1 wherein the stud is inserted into the stud supporting component of the tailgate bracket and the central core of the spring body in order for the coiled spring to act as a labor-saver.

14. The labor-saving truck tailgate device according to claim 1 wherein one end of the coiled spring is inserted into the spring-end supporting component of the tailgate bracket which is called a spring anchoring pipe.

15. The labor-saving truck tailgate device according to claim 1 wherein one end of the coiled spring is connecting to the spring- end holding unit or leaning onto the spring- end supporting unit.

16. The labor-saving truck tailgate device according to claim 1 wherein one end of the coiled spring is inserted between the tailgate and the lower edge of the truck body, providing that its size and angle fits well to the lower edge of the truck body.

17. The labor-saving truck tailgate device according to claim 1 wherein the coiled spring is assembled with the tailgate bracket by inserting one end of the coiled spring into the spring anchoring pipe and tuning or adjusting the spring body so that its center is aligned with the spring anchoring pipe, inserting the stud into the stud insertion pipe or the bracket and the spring body, and locking the stud with a supporting ring and a retaining ring.

18. The labor-saving truck tailgate device according to claim 1 wherein the size and number of coils or loops in the coiled spring depends on the size and weight of the tailgate and tailgate-related accessories.

1 9. The labor-saving truck tailgate device according to claim I wherein at least one formed metal sheet is used for the spring-end holding or supporting unit to fix to the truck body.

20. The labor-saving truck tailgate device according to any of claims 1 or 19 wherein an upper formed metal of the spring-end holding or supporting unit is characterized by having one end connecting to the lower portion of the truck body

21 . The labor-saving truck tailgate device according to claim 20 wherein one end of the upper formed metal comprises a concaved portion to support the protruded edge of the truck body wherein the nut is welded into and tighten with bolt to fix the spring-end holding or supporting unit to the truck body.

22. The labor-saving truck tailgate device according to claim 19 wherein the bolt is tightening to the upper formed metal sheet before tightening with nut to fix the bolt in place

23. The labor-saving truck tailgate device according to claim 1 wherein a lower formed metal sheet is held or lean on one end of the coiled spring.

24. The labor-saving truck tailgate device according to claim 1 wherein a brace is further used to fixed the lower formed metal sheet to one end of the coiled spring.

25. The labor-saving truck tailgate device according to claim 24 wherein the brace provides at least 2 holes for holding or supporting one end of the coiled spring.

26. The labor-saving truck tailgate device according to any of claims 1 or 23 wherein one portion of the lower formed metal sheet of the spring-end holding unit contains at least 2 bolts for connecting to the lower formed metal sheet and with 2 nuts to tighten the brace for fixing the spring-end.

27. The labor-saving truck tailgate device according to any of claims 1 or 23 wherein one nut is welded onto one portion of the lower formed metal sheet of the spring-end holding unit and wherein a hole for tightening in the bolt is present for tuning or adjusting the spring force.

28. The labor-saving truck tailgate device according to claim 27 wherein the act of tuning or adjusting the spring force is done by tightening the bolt through the lower formed metal sheet in order for the bolt to touch or lean on the lower surface of the upper formed metal or the spring-end holding unit.

29. The labor-saving truck tailgate device according to claim 1 wherein the spring end is assembled with the spring-end holding unit by inserting one end of the coiled spring into the spring anchoring unit with nut and wherein one end of the coiled spring is fixed tightly to the spring-end holding unit.

30. The labor-saving truck tailgate device according to claim 1 wherein the upper formed metal and lower formed metal sheets are assembled together by the stud.

31 . The labor-saving truck tailgate device according to claim 30 wherein the stud is inserted into the holes of the two metal sheets that are aligned on the same plane and wherein the stud is fixed with the retaining ring.

32. The labor- saving truck tailgate device according to claim 1 wherein the spring-end supporting unit comprises a truck body connecting component and a spring- end supporting component.

33. The labor-saving truck tailgate device according to claim 32 wherein the truck body connecting component comprises at least two upper formed metal sheets and wherein each sheet fits well to the truck body.

34. The labor-saving truck tailgate device according to claim 33 wherein the upper formed metal sheet further contains connecting tools such as nut and bolt which are used to fix the supporting unit and the truck body.

35. The labor-saving truck tailgate device according to claim 32 wherein the spring-end supporting unit comprises the lower formed metal sheet and wherein is connected to the upper formed metal sheet with connecting tools such as nut and bolt.

36. The labor-saving truck tailgate device according to claim 35 wherein one end of the lower formed metal sheet touches or leans on one end of the coiled spring for the purpose of labor-saving.

37. The labor- saving truck tailgate device according to claim 1 wherein the spring-end supporting unit is connected to the truck body with the upper formed metal sheet and wherein one end which is used to support the spring end is protruded from the truck edge which is the lower formed metal sheet for supporting the spring end for withstanding the force of rotation.