JPH0518377Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to a pantograph-type power jack used mainly when changing automobile tires or installing tire chains.

(Prior art) Installing a tire chain for changing a car tire requires a jack to lift the car body.
Usually, a highly portable pantograph-type manual jack is stored in the trunk. This jack requires a great deal of effort to use in the summer or during snowy seasons, as it raises and lowers the receiving plate by rotating a manual handle, and is extremely difficult for female drivers to use. On the other hand, as disclosed in Utility Model Application Publication No. 63-88689, etc., a device has been proposed in which a DC motor is used to rotate the threaded rod of a manual jack.

(Problem to be solved by the invention) In a conventional device in which a manual jack is operated by a DC motor, it is necessary to check the lifting and lowering status of the jack when the motor is in operation. If you rotate it, you will easily damage the weak part of the jack. Also, while operating the DC motor, it is necessary to hold the heavy motor in a predetermined position on the jack,
This alone is quite hard work.

The present invention was proposed to improve the above-mentioned problems with conventional automobile jacks, and provides a pantograph-type power jack that spins idly when the threaded rod reaches its limit position to prevent damage to parts. It is intended to. Another object of the present invention is to provide a pantograph-type power jack in which an electric motor and a gearbox can be attached to and removed from the jack, and the jack can be raised and lowered using a manual handle.

(Means for Solving the Problems) In order to achieve the above object, the power jack 1 according to the present invention connects four links 3 and 4 to each other via a plurality of mounting pins 2, as shown in FIG. Assemble and configure the upper link 3 and lower link 4 into a shape.
The threaded rod 7 is rotatably inserted through the two pins 5 and 6 that connect the front connecting pin 5.
is provided with a female threaded hole 8 into which the threaded rod 7 is screwed (the second
On the other hand, the rear connecting pin 6 is provided with a through hole 9 for a bearing. The power jack 1 rotates a threaded rod 7 using an electric motor 10 installed at the rear, thereby raising and lowering a receiving plate 12 using a base 11 as a fulcrum. The power jack 1 is provided with a small diameter portion 13 at the rear of the threaded rod 7 with a length that allows the female threaded hole 8 of the connecting pin 5 to fit therein, and the diameter of the small diameter portion is smaller than the inner diameter of the female threaded hole 8. Small diameter part 13
The elastic member is installed close to. In addition to the coil spring 14 as shown in the figure, this elastic member may be a plate spring or a rubber tube. contacts the circumferential surface of and urges it outward. On the other hand, it is preferable to provide a small diameter part 15 at the tip of the threaded rod 7 with a length that allows the female threaded hole 8 of the connecting pin 5 to fit into the female threaded hole 8.
smaller than the inner diameter of

In the power jack 1 of the present invention, the plug 20 of the electric motor 10 shown in FIG. 3 may be connected to a cigarette lighter socket (not shown) of an automobile during use. In the power jack 1, the receiving plate 2 is installed on the rear connecting pin 6.
It is preferable to hold the gearbox 22 at 1 and insert the rotating shaft 23 of the gearbox into the rectangular hole 24 in the rear end surface of the threaded rod 7 (see FIG. 4). When the removable electric motor 10 and gearbox 22 are removed, a manual handle 26 can be attached to the rectangular hole 24 on the rear end surface of the threaded rod, either directly or via a bracket 25 (FIG. 5).

(Function) The power jack 1 according to the present invention rapidly rotates the threaded rod 7 by the electric motor 10 installed at the rear, and when the jack reaches its maximum raised position or maximum lowered position, the female screw of the connecting pin 5 The hole 8 fits into the small diameter portion 13 or 14 of the threaded rod 7, and the threaded rod 7
Since the threaded rod rotates idly, the threaded rod is not rotated beyond its limit position. When operation by the electric motor 10 is resumed, an elastic member such as a coil spring 14 disposed close to the small diameter portion 13 comes into contact with the circumferential surface of the connecting pin 5 and urges it outward. It is easy to re-engage the hole 8 with the threaded rod 7. Power jack of this invention 1
Now, when the electric motor 10 cannot be used, if the electric motor 10 and gearbox 22 are removed,
Directly into the square hole 24 of the threaded rod 7 or with the bracket 25
It is only necessary to attach the manual handle 26 via the screwdriver and rotate it manually.

(Example) To explain the present invention based on the drawings, FIG. 1 shows the entire power jack 1 according to the present invention. In the power jack 1, four metal links 3 and 4 with a U-shaped cross section and approximately the same dimensions are used, and a through hole for pin insertion is formed at the front and rear ends of each link. Two through holes for pin insertion are also formed in the base 11 and the receiving plate 12 at predetermined intervals. As a result, multiple mounting pins 2
The four links 3 and 4 can be assembled into a rhombic shape through the four links 3 and 4, and the upper link 3 and lower link 4 are partially overlapped and connected by two pins 5 and 6 having larger diameters. As shown in FIG. 2, the front connecting pin 5 having the notched flat surface 30 is provided with a female threaded hole 8 in the diametrical direction in the middle portion thereof into which the threaded rod 7 is screwed. A certain rear connecting pin 6 has a threaded rod 7 in its middle part.
A through hole 9 for a bearing is provided in the diametrical direction. The rear part of the threaded rod 7 is provided with a small diameter part 13 long enough to fit into the female threaded hole 8 of the connecting pin 5, and the diameter of the small diameter part is required to be smaller than the inner diameter of the female threaded hole 8. , usually have approximately the same diameter. A male threaded portion 31 is carved forward of this small diameter portion 13, and the threaded rod 7 is rotatably inserted into the female threaded hole 8 and the through hole 9 so that the male threaded portion engages with the female threaded hole 8 of the connecting pin 5. Insert. The threaded rod 7 has a small diameter portion 13 and a connecting pin 6.
A compression coil spring 14 is fitted between the small diameter portion 1 and a protective ring 32 fixed to the front end of the coil spring.
3, when the female screw hole 8 of the connecting pin 5 fits into the small diameter part 13, the ring 3
2 contacts the circumferential surface of the connecting pin 5 and urges it outward.

On the other hand, the tip of the threaded rod 7 is also provided with a small diameter part 15 having a length that allows at least the female threaded hole 8 to fit into it, and the diameter of the small diameter part is required to be smaller than the inner diameter of the female threaded hole 8. Usually they have approximately the same diameter.

A gearbox 22 and an electric motor 10 housed in a plastic housing are removably integrated and installed at the rear of the power jack 1. A horizontal insertion part 33 is formed above the cylindrical gearbox 22, and the protruding part 34 of the U-shaped receiving plate 21, which is pivoted to the rear connecting pin 6, is inserted into the insertion part 33, and a bolt (not shown) is inserted into the insertion part 33. gearbox 22 is held by screwing in the In this holding state, the square rotating shaft 2 of the gearbox
3 is fitted into a square hole 24 (FIG. 4) on the rear end surface of the threaded rod. A pair of protrusions 35 are formed on the rear circumferential wall of the gearbox 22, and a pair of buckles 36 are attached to the front circumferential wall of the electric motor 10, and by tightening the buckles, the two are integrated during use. The electric motor 10 is separated from the gearbox 22, so if a polisher (not shown) or the like is attached to the motor via another gearbox, or a small air compressor (not shown) is attached to the motor, it can be used for car polishing or other purposes. It becomes possible to inflate tires. The direction of rotation of the electric motor 10 can be changed by switching the handheld switch 37.
It is a 12V DC motor, and the motor is wired through a hand-held switch 37 to a plug 20, and the plug can be connected to a car's cigarette lighter socket when in use.

The power jack 1 of the present invention is constructed by fitting the mounting adapter 40 compatible with each vehicle onto the receiving plate 12, and then
It is placed below a predetermined position on the vehicle body, and the plug 20 of the electric motor 10 is connected to the cigarette lighter socket of the vehicle. Next, the button 41 of the hand-held switch 37 is pressed as appropriate to rotate the threaded rod 7 by the electric motor 10, thereby raising and lowering the receiving plate 12 using the base 11 as a fulcrum. electric motor 1
Since the 0 cord 42 is quite long, the operator can work while checking the lifting and lowering status of the jack 1.

In the power jack 1 according to the present invention, when the screw rod 7 is rotated in the forward direction by the electric motor 10 and the jack 1 reaches the maximum raised position as shown in FIG. The threaded rod 7 is fitted into the small diameter portion 13 of the rod 7 and rotates idly. Therefore, the threaded rod 7 is not rotated beyond its limit position, and at this time, the protective ring 32 of the coil spring 14 comes into contact with the circumferential surface of the connecting pin 5 and urges it outward. There is. Subsequently, when the threaded rod 7 is rotated in the reverse direction by the electric motor 10, since the connecting pin 5 is urged outward by the protective ring 32, the female threaded hole 8 easily engages with the male threaded portion 31, and the jack 1 Start descending operation. On the other hand, the downward operation of the jack 1 by the reverse rotation of the threaded rod 7 continues, and when the jack reaches its maximum lowered position, the female threaded hole 8 is inserted into the small diameter portion 15.
Since the threaded rod 7 becomes stuck in the threaded rod and rotates idly, the threaded rod is not rotated beyond its limit position. Next, when the threaded rod 7 is rotated in the forward direction, the jack 1
Due to the restoring force, the female threaded hole 8 easily engages with the male threaded portion 31, and the upward operation of the jack 1 is resumed.

When the electric motor 10 cannot be used due to a cord breakage accident, etc., the electric motor 10 and gearbox 22 can be removed from the jack 1. By inserting the square protrusion 43 of the bracket 25 (FIG. 5) into the square hole 24 of the threaded rod 7, a commercially available manual handle 26 can be installed.
It is possible to rotate manually by Also,
If the handle (not shown) has a tip similar to the square projection 43, the threaded rod 7 can be directly turned with the handle.

(Effects of the invention) The power jack according to the invention raises and lowers the strike plate by rotating a threaded rod using an electric motor installed at the rear of the jack, so there is no need to hold the heavy motor by hand at a predetermined position on the jack. Even a weak female driver can easily change tires in the summer or install tire chains during snowy conditions. When the jack of the present invention reaches its maximum raised position or maximum lowered position, the female threaded hole of the connecting pin fits into the small diameter part of the threaded rod, causing the threaded rod to spin freely, pushing the threaded rod beyond its limit position. Since it does not rotate, there is less damage to the parts of the jack, and the jack can be used safely for a long period of time.

The power jack of the present invention can be used by simply connecting the electric motor's plug to the car's cigarette lighter socket.When the electric motor cannot be used, it can be removed and the manual handle attached to the threaded rod. You can do it manually. This electric motor can be detached from the power jack and attached with an air compressor or polisher as desired, and can also be used for tire inflation or car polishing.

[Brief explanation of the drawing]

Fig. 1 is a side view showing a pantograph type power jack according to the present invention, Fig. 2 is a cross-sectional view showing the main parts of the power jack shown in Fig. 1 at the maximum raised position, and Fig. 3 shows the electric motor and gearbox used in the present invention. FIG. 4 is a side view of a main part showing the vicinity of the rear end surface of a threaded rod in a power jack, and FIG. 5 is a perspective view of a bracket and a manual handle that can be used with the present invention. 1...Power jack, 2...Mounting pin, 3,
4... Link, 5, 6... Connection pin, 7... Threaded rod, 8... Female threaded hole, 9... Through hole, 10... Electric motor, 11... Base, 12... Reception plate, 13
... Small diameter part, 14 ... Coil spring, 15 ... Small diameter part, 20 ... Plug, 21 ... Reception plate, 22 ... Gearbox, 23 ... Rotating shaft, 2
4...Square hole, 25...Bracket, 26...Manual handle.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. Assemble four links in a rhombus shape via mounting pins, and insert a threaded rod into the two pins connecting the upper and lower links so that they can rotate freely, and screw the screws using an electric motor. It is a pantograph type power jack that raises and lowers a receiving plate using a base as a fulcrum by rotation of a rod, and a small diameter part is provided at the rear part of the threaded rod with a length that allows the female threaded hole of the front connecting pin to fit into it. The diameter of the part is smaller than the inner diameter of the female threaded hole, and an elastic member is installed close to this small diameter part, so that when the female threaded hole of the front connecting pin fits into the small diameter part of the threaded rod, this A power jack that urges the connecting pin outward. 2. The power jack according to claim 1, wherein the tip of the threaded rod is also provided with a small diameter part long enough to fit into the female threaded hole of the front connecting pin, and the diameter of the small diameter part is smaller than the inner diameter of the female threaded hole. . 3 Assemble the four links in a diamond shape through the mounting pins, and insert the threaded rod into the two pins that connect the upper and lower links so that they can rotate freely, and use the base as a fulcrum by rotating the threaded rod with an electric motor. It is a pantograph-type power jack that raises and lowers a receiving plate, and the plug for the electric motor is connected to the cigarette lighter socket of a car when in use, and the receiving plate installed on the connecting pin at the rear holds the electric motor and gearbox. If the rotating shaft of this gearbox is inserted into the square hole on the rear end of the threaded rod and the removable electric motor and gearbox are removed, a manual handle will be inserted into the square hole on the rear end of the threaded rod, either directly or through a bracket. Power jack that can be installed.