Tailgate lift apparatus and method

Abstract

A pickup truck tailgate lift apparatus attachable with no body modification, to create a powered lift function utilizing the tailgate as a load platform. Two side assemblies, which extend a lift mechanism beyond the rear bumper, are mounted over the existing tailgate pivot and upper cable anchor pin so that the tailgate may be opened and closed with respect to the side assemblies in the same manner that it is opened and closed with respect to the cargo box. The vehicle tailgate is attached to an electric drive plate assembly so that the tailgate, and a load place on the tailgate, is raised or lowered as the drive plate assembly is raised and lowered. In one embodiment, an electric motor is placed on each side to drive a treaded rod to move a drive plate up or down.

Claims

1. An electric powered tailgate lift apparatus for a vehicle, the vehicle comprising a pickup, the pickup comprising, a first side tailgate pivot pin, a second side tailgate pivot pin, a cargo box having a rear end, and a rear bumper, the tailgate lift apparatus comprising a vehicle tailgate; a first side assembly comprising a first electric motor, a first drive plate assembly, a first side panel assembly, configured to be mounted to the pickup first side tailgate pivot pin, and configured to extend the first drive plate assembly past the pickup bumper, a first side assembly pivot pin configured to permit the vehicle tailgate to be pivoted relative to the first side assembly pivot pin, and a first side assembly striker, configured to permit the vehicle tailgate to be latched in a vertical closed orientation; a second side assembly comprising a second drive plate assembly, and a second side panel assembly, configured to be mounted to the pickup second side tailgate pivot pin, and configured to extend the second drive plate assembly past the bumper, a second side assembly pivot pin configured to permit the vehicle tailgate to be pivoted relative to the second side assembly pivot pin, and a second side assembly striker, configured to permit the vehicle tailgate to be latched in a vertical closed orientation; a floor panel configured to extend rearward from the rear end of the vehicle cargo box; wherein the vehicle tailgate is configured to be pivotally attached to the first and second side tailgate pivot pins when the lift apparatus is not installed on the vehicle and to the first and second side assembly pivot pins when the lift apparatus is installed on the vehicle, and wherein the first and second side assemblies are configured to move the vehicle tailgate in a substantially linear vertical direction.

2. The electric powered tailgate lift apparatus of claim 1 wherein the second side panel assembly further comprises a second electric motor.

3. The electric powered tailgate lift apparatus of claim 1 further comprising a first gear and motor mounting plate, such that the gear and motor mounting plate supports the first electric motor and a first gear assembly; and a first threaded shaft which raises and lowers a tailgate support with respect to the first side panel assembly.

4. The electric powered tailgate lift apparatus of claim 1 wherein the first gear assembly further comprises a drive motor assembly comprising the first electric motor; a gear-pinion motor mount; a motor mount plate; a gear shaft mount plate assembly; a main screw drive plate assembly; and a wheel gear.

5. The electric powered tailgate lift apparatus of claim 1 wherein the first drive plate assembly further comprises a gear wheel transmission, and a gear box housing.

6. The electric powered tailgate lift apparatus of claim 1 further comprising a first side harness assembly comprising a limit switch, an encoder, and an LED tail light socket.

7. The electric powered tailgate lift apparatus of claim 6 wherein the limit switch is an electronic limit switch.

8. The electric powered tailgate lift apparatus of claim 6 further comprising a second side harness assembly comprising a limit switch, an encoder, and an LED tail light socket.

9. The electric powered tailgate lift apparatus of claim 1 further comprising an up-stop limit switch; an up/down control switch; and an optical proximity switch indicating that the tailgate is in the horizontal load open position prior to operating the tailgate downward movement.

10. The electric powered tailgate lift apparatus of claim 1 further comprising an up-stop limit switch; an up/down control switch; and a plunger switch indicating that the tailgate is in the horizontal load open position prior to operating the tailgate downward movement.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIGS. 1-16 are subassembly drawings of one embodiment of the current invention as referenced in the element list below.

(2) FIG. 1 is an exploded side perspective view of a right side inner/outer tube assembly; a left side inner/outer tube assembly; and a floor panel of a first embodiment of a tailgate lift device.

(3) FIG. 2 is an electrical schematic of the tailgate lift device of FIG. 1.

(4) FIG. 3A is is a side view of a side panel assembly of the tailgate lift device of FIG. 1.

(5) FIG. 3B is a front view of the side panel assembly of FIG. 3A.

(6) FIG. 3C is an isometric view of the side panel assembly of FIG. 3A.

(7) FIG. 4 is an exploded side perspective view of a right side inner tube drive plate assembly of the tailgate lift device of FIG. 1.

(8) FIG. 5 is an exploded view of a top portion of the main screw drive plate assembly of the tailgate lift device of FIG. 1.

(9) FIG. 6 is an exploded view of a motor/plate/gear drive assembly of the tailgate lift device of FIG. 1.

(10) FIG. 7 is an exploded view of the motor/plate/gear drive assembly of FIG. 6.

(11) FIG. 8 is an exploded view of a thrust bearing assembly of the tailgate lift device of FIG. 1.

(12) FIG. 9 is an exploded view of a plate and gear assembly of the tailgate lift device of FIG. 1.

(13) FIG. 10 is side perspective view of an inner tube and drive plate assembly of the tailgate lift device of FIG. 1.

(14) FIG. 11A is a side view of an inner tube and lift plate assembly of the tailgate lift device of FIG. 1.

(15) FIG. 11B is a top view of the inner tube and lift plate assembly of the tailgate lift device of FIG. 11A.

(16) FIG. 11C is an isometric view of the inner tube and lift plate assembly of the tailgate lift device of FIG. 11A.

(17) FIG. 12A is a side view of the tube assembly of the tailgate lift device of FIG. 1.

(18) FIG. 12B is a top view of the tube assembly of the tailgate lift device of FIG. 12A.

(19) FIG. 12C is a side perspective view of the tube assembly of the tailgate lift device of FIG. 12A.

(20) FIG. 13A is a side view of the inner tube assembly of the tailgate lift device of FIG. 1.

(21) FIG. 13B is a first isometric view of the inner tube assembly of the tailgate lift device of FIG. 13A.

(22) FIG. 13C is a second isometric view of the inner tube assembly of the tailgate lift device of FIG. 13A.

(23) FIG. 14A is a side view of the outer tube assembly of the tailgate lift device of FIG. 1.

(24) FIG. 14B is a top view of the outer tube assembly of FIG. 14A.

(25) FIG. 14C is a front view of the outer tube assembly of FIG. 14A.

(26) FIG. 14D is an isometric view of the outer tube assembly of FIG. 14A.

(27) FIG. 15A is a side view of the outer tube assembly and floor support bracket of the tailgate lift device of FIG. 1.

(28) FIG. 15B is a top view of the outer tube assembly and floor support bracket of FIG. 15A.

(29) FIG. 15C is a front view of the outer tube assembly and floor support bracket of FIG. 15A.

(30) FIG. 15D is an isometric view of the outer tube assembly and floor support bracket of FIG. 15A.

(31) FIG. 16A is a side view of the side panel assembly of the tailgate lift device of FIG. 1.

(32) FIG. 16B is a top view of the side panel assembly of FIG. 16A

(33) FIG. 16C is an isometric view of the side panel assembly of FIG. 16A.

(34) FIG. 17 is a side view of an EPLM device with a tailgate in a raised position.

(35) FIG. 18 is a side view of an EPLM device with a tailgate in a lowered position.

(36) FIG. 19 is a rear perspective view of a right side assembly of an EPLM device with a tailgate in a raised position.

(37) FIG. 20 is a rear perspective view of a right side assembly of an EPLM device with a tailgate in a lowered position.

(38) FIG. 21 is a schematic of the left side wire harness assembly.

(39) FIG. 22A is rear view of the right side assembly of FIG. 16 with a motor and gear assembly.

(40) FIG. 22B is cross section view of the right side assembly of FIG. 16 with a motor and gear assembly.

(41) FIG. 23 is a rear perspective view of an EPLM device with a tailgate in a lowered position.

DESCRIPTION OF EMBODIMENT

(42) Electric Powered Lift Mechanism (EPLM)

(43) This embodiment provides an Electric Powered Lift Mechanism (EPLM).

(44) The following element numbers are referenced in the figures. Pick-Up 60 rear bumper 70 tailgate 80 tailgate cable 81 cargo box 85 tailgate pivot 95 upper cable anchor pin 96 Electric Powered Lift Mechanism (EPLM) 100 side assembly pivot mounting notch 101 side assembly striker mounting slot 102 new tailgate pivot 104 new tailgate striker 105 1000 VEHICLE INSTALLATION-POWER LIFTFIG. 1 2300 INNER/OUTER TUBE ASY (FINAL) 2300a right side INNER/OUTER TUBE ASY 2260 PANEL-FLOOR 2544 SCREW-FLOOR ATT. 2261 BRACE-LOWER SUPPORT 2262 SCREW-SUPPORT ATT. 2000 ELECTRICAL COMPONENT SCHEMATIC DIAGRAMFIG. 2 2857 HARNESS ASY-LH 2858 PCU CONTROL UNIT 2859 SWITCH-TAILGATE UP-DOWN FUNCTION 2860 TAIL LIGHT-LED STOP/TURN/TAIL LIGHT 2861 SWITCH-TAILGATE HORIZONTAL LOAD POSITION 2272 PANEL ASY-SIDE COLLAR ATT.FIG. 3 2733 PANEL ASY-SIDE (WELD) 2267 COLLAR-LOWER BODY 2801 RIVET-COLLAR ATT 2300 OUTER-INNER TUBE ASY (FINAL)FIG. 4 2526 INNER TUBE/DRIVE PLATE ASY 2700 TUBE ASY-OUTER (FINAL) 2564 SCREW-GEAR/TUBE/PLATE ASY ATT. 2467 CAP-OUTER TUBE CLOSURE 2633 NYLON SHEET 2523 SCREW-NYLON SHEET ATT. 2722 BEARING-ROLLER 2772 PIN-ROLLER 2777 SPACER-CENTER 2776 SPACER-OUTER 2753 CIRCLIP-RETAINER PIN 2325 PLATE ASY-MAIN SCREW DRIVEFIG. 5 2524 PLATE-BALL NUT MOUNT 2301 SCREW-MAIN DRIVE 2302 NUT-MAIN SCREW DRIVE 2303 SCREW-SET MAIN SCREW 2654 PIN-DOWEL ROLLER 2622 BEARING-ROLLER 2406 NUT-PLATE STOP 2400 MOTOR/PLATE/GEAR ASY-DRIVEFIG. 7 2413 MOTOR ASY-DRIVE 2475 GEAR-PINION MOTOR MOUNT 2408 PLATE-MOTOR MOUNT 2410 SCREW-MOTOR/PLATE ATT. 2412 SCREW-SET GEAR ATT 2401 GEAR BOX/TUBE/DRIVE ASYFIG. 6 2514 GEAR WHEEL TRANSMISSION 2520 HOUSING-GEAR BOX 2521 SCREW-GEAR BOX ATT. 2517 BEARING-NEEDLE 2773 CAP-BEARING STOP 2526 inner tube/drive plate assy 2474 PLATE ASY-GEAR SHAFT MOUNTFIG. 8 2471 PLATE-TUBE OUTER 2245 PIN-DOWEL GEAR SHAFT 2522 BEARING-TRUST 2573 SWITCH-LIMIT (UP STOP) 2472 SCREW-SWITCH ATT. 2500 GEAR/PLATE ASY-MAIN DRIVE SHAFTFIG. 9 2474 PLATE ASY-GEAR SHAFT MOUNT 2325 PLATE ASY-MAIN SCREW DRIVE 2470 GEAR-WHEEL 2518 PIN-DOWEL GEAR LOCK 2526 INNER/TUBE DRIVE PLATE ASYFIG. 10 2675 TUBE ASY-INNER (FINAL) 2677 SCREW-GEAR/PLA/TUBE ATT 2600 TUBE ASY-INNER (WELD)FIG. 11 2625 TUBE-INNER 2626 PLATE-INNER SUPPORT 2627 PLATE-OUTER SUPPORT 2634 TUBE ASY-REAR REINF (WELD) 2634 tube assembly-rear reinforcement (welded)FIG. 12 2635 TUBE-REAR REINFORCEMENT 2636 NUT-WELD BRACE SUPPORT ATT 2675 TUBE ASY-INNER (FINAL)FIG. 13 2600 TUBE ASY-INNER (WELD) 2632 SOCKET-TAILGATE PIVOT RH 2649 SOCKET-TAILGATE PIVOT LH 2549 BUMPER & SCREW ASY-ALIGNMENT 2679 PLUG RC COVER-REAR REINF 2647 SCRIBET & SCREW ASY-CABLE ATT 2860 NUT-SOCKET ATTACHMENT 2700 TUBE ASY-OUTER (FINAL)FIG. 14 2268 LATCH-UPPER LOCK 2269 SCREW-LATCH ATT 2648 BUMPER OVERSLAM/SCREW 2828 STRICKER ASY 2272 NUT-STRICKER ATT 2751 J-NUT-FLOOR ATT 2701 TUBE ASY-OUTER (WELD) 2701 TUBE ASY-OUTER (WELD)FIG. 15 2738 TUBE-OUTER 2272 PANEL ASY-SIDE COLLAR ATT 2242 BRACKET-FLOOR SUPPORT 2771 BRACKET-STRICKER SUPPORT 2733 PANEL ASY-SIDE (WELD)FIG. 16 2740 PANEL-SIDE 2741 REINF-SIDE PANEL 2270 NUT-WELD M-101.5
Overview

(45) FIG. 18 is a side view of an EPLM device 100 with a tailgate in a lowered position. FIG. 17 is a side view of an EPLM device with a tailgate in a raised position. FIG. 20 is a rear perspective view of a right side assembly of an EPLM device with a tailgate in a lowered position. FIG. 19 is a rear perspective view of a right side assembly of an EPLM device with a tailgate in a raised position. In this example, an EPLM device 100 is attached to the rear portion of a pickup truck 60. The EPLM device has a right side inner/outer tube assembly 2300a, a left side inner/outer tube assembly, and a floor panel 2260. In this embodiment, electric motors are provided in each side assembly, and the motors raise and lower an inner tube/drive plate assembly 2526. The vehicle tailgate is attached to the drive plate assembly so that the tailgate, and a load place on the tailgate, is raised or lowered as the drive plate assembly is raised and lowered.

(46) Each side inner/outer tube assembly includes an side panel assembly 2733 which extends the inner/outer tube assembly past the bumper, and permits the lifting elements and tailgate to move without obstruction from the rear bumper 70. The EPLM device raises or lowers the tailgate 80.

(47) The vehicle tailgate attaches to the side assemblies in the same manner that it attaches to the truck. In this embodiment, the EPLM device is operated from the vehicles electric system, and the electrical connections are made at a single connector provided by the vehicles rear bumper or hitch. The side assemblies are easily removed, so that the truck may be operated in either its standard configuration or with the EPLM device installed.

(48) FIG. 1 is an exploded side perspective view of a right side inner/outer tube assembly 2300a; a left side inner/outer tube assembly; and a floor panel 2260.

(49) Side Assembly and Tailgate Mounting

(50) The side assemblies are mounted over the existing tailgate pivot 95 and upper cable anchor pin 96 so that the side assembly pivot mounting notch 101 in the side panel assembly 2733 is positioned over the tailgate pivot, and the side assembly striker mounting slot 102 is mounted over the cable anchor pin.

(51) A new tailgate pivot 104 and new tailgate striker 105 are provided on the inner tube drive plate assembly 2526 so that the tailgate may be opened and closed with respect to the side assemblies in the same manner that it is opened and closed with respect to the cargo box.

(52) As shown in FIG. 1, the floor panel 2260 and brace 2261 may be quickly installed with four screws 2262 and 2544. When installed, the floor panel acts to secure the side assemblies in a mounted position over the tailgate pivot and upper cable anchor pin.

(53) FIG. 3A is a side view of a side panel assembly 2733. FIG. 3B is a front view of the side panel assembly. FIG. 3C is an isometric view of the side panel assembly.

(54) FIG. 11A is a side view of an inner tube and lift plate assembly 2600. In this example, welded components of the inner tube and lift plate assembly comprise an inner tube 2625, an inner plate support 2626, an outer plate support 2627, and a tube-rear reinforcement 2635. FIG. 11B is a front view of the inner tube assembly of the embodiment of FIG. 11A. FIG. 11C is an isometric view of the inner tube assembly of the embodiment of FIG. 11A.

(55) FIG. 4 is an exploded side perspective view of a right side inner tube drive plate assembly 2526 and the outer tube 2700. In this example, the inner tube drive plate assembly 2526 comprises a nylon sheet 2633 with attachment screw 2523; an outer tube closure cap 2467; a roller bearing 2722; a roller pin 2772; center spacer 2777; outer spacer 2776; and retainer pin 2753.

(56) FIG. 14A is a side view of the outer tube assembly 2700 of the embodiment of FIG. 1. FIG. 14B is a top view of the outer tube assembly of the embodiment of FIG. 14A. FIG. 14C is a front view of the outer tube assembly of the embodiment of FIG. 14A. FIG. 14D is an isometric view of the outer tube assembly of the embodiment of FIG. 14A.

(57) FIG. 15A is a side view of the outer tube 2738 assembly and floor support bracket 2742 of the embodiment of FIG. 1. FIG. 15B is a top view of the outer tube assembly and floor support bracket of the embodiment of FIG. 15A. FIG. 15C is a front view of the outer tube assembly and floor support bracket of the embodiment of FIG. 15A. FIG. 15D is an isometric view of the outer tube assembly and floor support bracket of the embodiment of FIG. 15A.

(58) Motor and Gear Assembly

(59) FIG. 22A is rear view of the right side assembly of FIG. 19 with a motor and gear assembly.

(60) FIG. 22B is cross section view of the right side assembly of FIG. 16 with a motor and gear assembly which shows the outer tube 2738, the inner tube 2625, with the motor mounted with respect to the outer tube.

(61) A gear and motor mounting plate 2410 supports an electric motor and a gear assembly. The electric motor and gears turn a threaded shaft which raises and lowers the inner tube and tailgate support with respect to the inner tube.

(62) FIG. 6 is an exploded view of a motor/plate/gear drive assembly 2400 of the embodiment of FIG. 1. FIG. 7 is an exploded view of the plate and gear assembly 2325 of FIG. 6. The motor/plate/gear assembly drive 2400 comprise a drive motor assembly 2413, a gear-pinion motor mount, and a motor mount plate 2408. The gear box/tube/drive assembly 2401 comprises a gear wheel transmission 2514, a gear box housing 2520, a gear box attachment screw, a needle bearing 2517, and a bearing stop cap 2773. The gear plate assembly 2500 of the main drive shaft 2500 includes a gear shaft mount plate assembly 2474, a main screw drive plate assembly, a wheel gear 2470 and a dowel gear lock.

(63) FIG. 5 is an exploded view of a top portion of the main screw drive plate assembly 2325 which comprises a ball nut mount plate 2524, a main drive screw 2301 with main screw drive nut 2302 and set screw 2303, a dowel roller pin 2654, a roller bearing 2622, and a stop plate nut 2406.

(64) Electrical Components

(65) FIG. 2 is an electrical schematic 2000 of one embodiment of the current invention.

(66) The following review is a functional description of electrical components and wire harnesses and how they are utilized, installed, attached and harness connected into the example tailgate assembly.

(67) Switch-Limit Up-Stop 2573:

(68) This switch is used to shut down the electrical system when the tailgate reaches the up horizontal load position. The switches, two required, are connected via the left/right wire harnesses to the PCB unit and pre-assembled. (See Plate assembly-Gear Shaft Mount 2474 for attachment.)

(69) Switch-Up/Down Control 2474:

(70) This switch controls the up and down tailgate load movement by an operator. When the tailgate reaches the up position, the system is automatically stopped as noted above and the switch reverts to the off position. The operator controls the down movement to a desired load level. A lower stop mechanism attached to the drive screw shaft 2325 is controls the lowest tailgate position. If this occurs the operator shuts down the system. The Switch, one required, is located on the outer side of the left side assembly 2701 and is pre-assembled to the left side harness assembly to communicate to the PCB unit. No remote control is required.

(71) Switch-Tailgate Horizontal Load Position 2861:

(72) This plunger switch or optical proximity switch indicates to the PCB unit that the tailgate is in the horizontal load open position prior to operating the tailgate downward movement. If the tailgate is in the upper closed lock position, the system will not function. The switch, one required, is pre-assembled to the left side harness assembly and nut attached to the left side tube assembly striker bracket 2771.

(73) Tail Light-LED Stop/Turn/Tail Light 2860:

(74) The light assembly wire attachment is not included in the wire harness assembles. The lighting system wire is attached to the wire harness as shown in attached sketch. A separate wire is required in the left and right wire harnesses to provide its connection to the vehicle's 12-voltage electrical system. The lighting system is independent of the PCB control system. This wire connect is similar to the current trailer vehicle connection. The final light assembly screw attachment to the outer tube is as shown 2000.

(75) PCB Control Unit 2858:

(76) The PCB Unit is utilized to monitor/control an Igarashi Motor/Encoder (Sensor) Assembly 2413 sequence parallel movement of the tailgate. The PCB unit is also monitors the three (3) switch functions as noted above. The unit, one required, shall require a self contained cover which shall be located in the space provided in the inner side of the left side tailgate assembly. The PCB unit is typically included in the lift side wire harness assembly.

(77) Harness Asy-RH 2800:

(78) The limit switch, motor/encoder and LED tail light are socket attached during harness installation process. The harness assembly lower floor attachment is fastened by a series of Xmas clips. The harness is socket connected to the left side harness assembly and attached to the floor pan during the customer installation of the tailgate lift assembly.

(79) Harness Asy-LH 2857:

(80) The left side harness assembly comprise the above components where noted with the motor, limit switch and LED tail light connected in the same manner as the right side. The lower attachment is the same as the right side with a socket connect to the right side harness. A socket lead from the harness to the vehicle's 12-volt trailer hitch system is required. Example limit switches include mechanical limit switches and electronic limit switches.

(81) Installation

(82) In one example, the end customer receives the Tailgate assembly in three (3) containers, one for each side assembly and one for the floor pan with fasteners. The customer installs the tailgate assemblies as follows. No modification to the truck cargo box 85 is required: Inspect if all components are enclosed in the boxes and read the installation instructions. Disconnect the two (2) tailgate cables from the cargo box and remove the tailgate. No tools are required. Insert each side assembly's lower collar into the cargo box tailgate pivot pins and pivot to the vertical position at the cargo box striker pins. Secure the lock latch 2268 to the striker pins via two (2) nuts 2272 on each side. Install the floor pan and secure to the lower support bracket 2261 via two (2) screws 2544. Connect the right side wire harness assembly to the left side wire harness assembly and secure to the floor pan clips. Insert the total wire harness assembly to the truck trailer electrical receptacle for the systems 12-volt system. Install the tailgate to the side assemblies, attach the cables on each side and check closed lock and open load positions. Inspect the lift system's operational performance prior to usage. Disengage the tailgate support cables from the top end and remove the tailgate. Install each side assembly by first inserting the lower side assembly collar system into the truck cargo box tailgate pivot pin and pivot into the vertical position until the side assembly contacts the cargo.

(83) FIG. 12 is a rear perspective view of an EPLM device 100 with a tailgate 80 in a lowered position. (This is a test device which includes a testing support stand).

(84) It is to be understood that the specific embodiments and examples described above are by way of illustration, and not limitation. Various modifications may be made by one of ordinary skill, and the scope of the invention is as defined in the appended claims.