CN222982737U - Electric chair base and electric chair comprising same - Google Patents

Abstract

The utility model provides an electric chair base, which comprises a first base, a second base and a third base. The second base is arranged on the first base and can tilt and swing backwards, the third base is arranged on the second base and can be lifted and moved, and the third base is lifted and moved by pulling a lifting telescopic rod. When the third base is lowered to the lowest point, since the third base cannot be lowered any further, the second base can be driven to tilt and swing backwards. Thus, the lifting height adjustment and the swing and tilting actions can be controlled by a single telescopic rod. The utility model has the characteristics of simple structure and diversified actions, provides the use function of freely adjusting the height at a controllable cost, and has excellent market value.

Description

Electric chair base and electric chair comprising same

Technical Field

The utility model relates to an electric chair.

Background

The existing electric chairs, such as those described in taiwan TWI548372, can provide a user with a back lying and a specific front azimuth angle between the chair seat, the chair back and the leg seat, and can support the back, the buttocks and the legs of the user with three specific angle support surfaces, providing a use function commonly known as "gravity-free chair" or "gravity-free chair".

On the other hand, the old or the disabled may have a very hard standing up from a sitting position due to degeneration of knees and other joints or muscles, so that there is a standing up chair capable of assisting in standing up, the seat of which can swing forward and tilt and the rear side of which is lifted up by electric drive, directly supporting and pushing up the buttocks of the user, and making the posture of the user close to standing up, so that the standing up action is more labor-saving and easy.

In order to improve the comfort and the use feeling of the standing-up chair, the backrest and the leg rest of the standing-up chair can be inclined or lifted by electric drive, for example, the patent of taiwan TWM487727 describes a standing-up chair, in the standing-up state, the seat cushion is inclined forwards by a telescopic power device, and the backrest is also inclined forwards to swing so as to enable the back to move forwards, thereby standing up, the leg rest is retracted backwards to avoid interference with standing up, in addition, the seat cushion can be inclined backwards by the telescopic power device when sitting, and the backrest is reclined, the leg rest is extended upwards, thereby providing a lying posture of a user 'gravity-free chair' and having comfort and labor saving.

However, the existing uprising chairs still have a considerable improvement in the control of the height of the seat. Because the length of each part of the body is different, the height of the chair surface slightly higher than the knees and slightly lower than the knees may be different by less than 5 cm, but a great feeling difference is brought to the user, especially when the user is inclined to assist in getting up, the improper height of the chair surface may cause the user to get up difficultly or be unbalanced and fall down, and the electric chairs and the getting-up chairs in the patents TWI548372 and TWM487727 in Taiwan in the front can be customized only according to the user if the height of the chair surface is to be adjusted, or the height of the chair surface is adjusted by adding a telescopic power device, so that the cost and the selling price of the getting-up chair are greatly improved.

Disclosure of utility model

One of the objects of the present utility model is to provide an electric chair, which has a function of adjusting the height of a seat without complicating the mechanism excessively and increasing the cost.

Accordingly, the utility model provides an electric chair base, which comprises a first base, a second base, a third base, a first connecting rod group and a lifting telescopic rod. The second base is arranged on the first base and can swing around a horizontal axis relative to the first base. The first connecting rod group is connected with the second base and the third base, so that the third base can move up and down between a descending position close to the second base and a ascending position far away from the second base. The lifting telescopic rod is connected with the third base and one of the first connecting rod groups and the first base, the lifting telescopic rod can move in a telescopic mode among a first lifting length, a middle lifting length and a second lifting length, the middle lifting length is between the first lifting length and the second lifting length, the lifting telescopic rod drives the third base to move in a lifting mode between the lifting position and the descending position when moving in a telescopic mode between the first lifting length and the middle lifting length, the third base is located at the descending position when the lifting telescopic rod is located at the middle lifting length, and the second base swings relative to the first base around the horizontal axis when the lifting telescopic rod moves in a telescopic mode between the middle lifting length and the second lifting length.

In the aforementioned electric chair base, the first link set may further include a first lifting rod and an auxiliary rod, one end of the first lifting rod is slidably and pivotally disposed on one of the second base and the third base, the auxiliary rod is pivotally connected to the one of the second base and the third base, and the other end of the first lifting rod is pivotally connected to the other of the second base and the third base, and the third base can move up and down between the lowered position and the raised position when the first lifting rod and the auxiliary rod pivot.

In the aforementioned electric chair base, the first link set may further include a first balance bar, wherein one end of the first balance bar is slidably and pivotally disposed on one of the second base and the third base along with the first lifting bar, and the other end of the first balance bar is pivotally connected to the other of the second base and the third base.

In the aforementioned electric chair base, one of the second base and the third base may further comprise a sliding rail, the first link set comprises a sliding seat slidably disposed on the sliding rail, the first lifting rod is pivotally connected to the sliding seat, and preferably, the first balance rod is also pivotally connected to the sliding seat.

In the aforementioned electric chair base, the first link set may further include a booster rod connected to one of the booster rod and the first lifting rod and swinging therewith, wherein one end of the lifting telescopic rod is pivoted to the booster rod, and the other end of the lifting telescopic rod is pivoted to the first base.

In the aforementioned electric chair base, the electric chair base may further comprise a fourth base, a sub-base and a lift telescopic rod, wherein the fourth base can swing relative to the third base, the fourth base has a limiting portion, the sub-base is pivotally connected to the fourth base and can pivot against or not against the limiting portion relative to the fourth base, the lift telescopic rod is connected to the third base and the sub-base, the lift telescopic rod can move telescopically between a first lift length, a middle lift length and a second lift length, the middle lift length is between the first lift length and the second lift length, when the lift telescopic rod moves telescopically between the first lift length and the middle lift length, the sub-base is driven to swing relative to the fourth base, when the lift telescopic rod is at the middle lift length, the sub-base abuts against the limiting portion, and when the lift telescopic rod moves from the middle lift length to the second lift length, the sub-base abuts against the limiting portion and pushes the fourth base to swing relative to the fourth base.

In the aforesaid electric chair base, the electric chair base may further comprise a second link set, wherein the second link set comprises a second lifting rod and a second balance rod, the second lifting rod is pivoted to the third base and the fourth base, the second balance rod is pivoted to the third base and the fourth base, and the third base, the second lifting rod, the fourth base and the second balance rod form a four-bar mechanism so that the fourth base can swing close to or far from the third base.

The utility model also provides an electric chair, which comprises a chair seat and a chair back, wherein the chair seat and the chair back are positioned above a third base of the electric chair base and can be driven to move when the third base is positioned, and preferably, the chair seat can be arranged on a fourth base, and the chair back is arranged on a subsidiary base.

Therefore, the utility model can control the lifting and the backward tilting of the third base by utilizing the single mechanism of the lifting telescopic rod, so that the electric chair has the functions of adjusting the height of the seat surface and lying back of the seat, and can further control the forward tilting swing of the fourth base and the backward tilting swing of the auxiliary base by utilizing the single mechanism of the lifting telescopic rod, so that the electric chair has the functions of assisting in lifting and lying back of the chair, and provides sufficient using functions on the premise of not only excessively increasing the cost by utilizing limited mechanisms and parts.

Drawings

Fig. 1 is a perspective view of a first embodiment of the electric chair of the present utility model.

Fig. 2 is an exploded perspective view of the electric chair according to the first embodiment of the present utility model.

Fig. 3 is an exploded perspective view of the first embodiment of the chair according to the present utility model from another perspective.

Fig. 4 is an exploded perspective view of a base of a first embodiment of the electric chair of the present utility model.

Fig. 5 is a partial exploded perspective view of a base of a first embodiment of the motorized chair of the present utility model.

Fig. 6 is a side view of the electric chair according to the first embodiment of the present utility model.

Fig. 7 is a schematic view of a mechanism of a first base, a second base and a third base of the electric chair base according to the first embodiment of the present utility model.

Fig. 8 to 9 are schematic views illustrating the operation of the lifting/lowering telescopic rod of the base of the electric chair according to the first embodiment of the present utility model.

Fig. 10 is a schematic view of a mechanism of a third base, a fourth base and a sub-base of the electric chair base according to the first embodiment of the present utility model.

Fig. 11 to 12 are schematic views of the motion of the lifting telescopic rod of the base of the electric chair according to the first embodiment of the present utility model.

Fig. 13 is a schematic view illustrating the height adjustment operation of the electric chair according to the first embodiment of the present utility model.

Fig. 14 is a schematic view of the assisting lifting action of the electric chair according to the first embodiment of the utility model.

Fig. 15 is a schematic view of the reclining motion of the electric chair according to the first embodiment of the present utility model.

FIG. 16 is a schematic view of the operation of the electric chair according to the first embodiment of the present utility model.

Fig. 17 is a side view of a second embodiment of the power chair of the present utility model.

Fig. 18 is a schematic view of a mechanism of a first base, a second base and a third base of a second embodiment of the electric chair according to the present utility model.

Reference numerals denote the seat portion 10, the seatback portion 20, the headrest portion 21, the footrest portion 30, the first base 40, the pivot portion 41, the pivot seat 42, the second base 50, the mounting portion 51, the bearing portion 52, the pivot seat 53, the slide rail 54, the third base 60, the slide rail 61, the first link group 70, the first lifter 71, the auxiliary lever 72, the first balance lever 73, the slider 74, the booster lever 75, the pivot shaft 76, the lifter 80, the fourth base 90, the pivot portion 91, the stopper 92, the sub-base 100, the seatback bracket 101, the abutment seat 102, the lifting lever 110, the second link group 120, the second lifter 121, the second balance lever 122, the footrest link group 130, and the footrest lever 140.

Detailed Description

In order that the utility model may be further understood, a preferred embodiment is described in conjunction with the accompanying drawings, the following detailed description of which:

Referring to fig. 1 to 3, the present utility model provides an electric chair, which comprises an electric chair base at the lower part, and a chair seat 10, a chair back 20 and a foot rest 30 mounted on the electric chair base, wherein the upper and lower longitudinal directions of the chair seat 10 and the back rest 20 are defined by the shape of a human body, such as the upper and lower directions of fig. 1, and the left and right transverse directions of fig. 1, such as the left and right upper directions of fig. 1, and the front and rear directions of fig. 1, such as the left and right upper directions. Depending on the use requirements and the form of the electric chair, the back portion 20 and the footrest portion 30 may be omitted, and the back support, footrest link group, footrest telescopic link and other related mechanisms for mounting the back portion 20 and the footrest portion 30 in the electric chair base described later may be omitted. The seat portion 10, the back portion 20 and the foot rest portion 30 are used for providing functions such as human body leaning, buffering, soft and comfortable touch feeling, and the like, and can be respectively used for supporting the buttocks, the back and the legs of the human body, the back portion 20 preferably extends upwards or is connected with another cushion body to form the head rest portion 21, the interior or the surface of the seat portion 10, the back portion 20 and the foot rest portion 30 are determined according to the use requirement, and appropriate massage, heating, heat preservation, ventilation and other devices or combination devices with any of the functions can be arranged, so that various use functions can be provided for the electric chair.

Referring to fig. 4 to 6, the electric chair base includes a first base 40, a second base 50, a third base 60, a first link assembly 70, a lifting telescopic rod 80, a fourth base 90, a sub-base 100, a lifting telescopic rod 110, a second link assembly 120, a reclining link assembly 130, and a reclining telescopic rod 140. It should be noted that, since the electric chair and the electric chair base are generally symmetrical left and right, the present utility model mainly uses the necessary structure from the viewpoint of the side view to describe the whole mechanism, and the rod and the connecting rod mentioned in the present utility model may use a single rod member in the case of having a proper cross-sectional shape and size, but are not limited to the case of using a single long rod member, and may be a pair of rod members, a group of rod members, an i-shaped frame, a mouth-shaped frame, a sun-shaped frame or the like having a straight shape on other sides.

The first base 40 is located at the bottom of the electric chair base for placement on the ground or other stable support, and other silence pads or cushions can be added below the first base 40, and the first base 40 has a pivot portion 41 and a pivot seat 42, specifically, the pivot portion 41 is a through hole extending along a horizontal axis.

The second base 50 is disposed on the first base 40 and can swing relative to the first base 40 about a horizontal axis defined by the pivot portion 41, and specifically, the second base 50 is pivoted to the pivot portion 41 of the first base 40. The second base has a mounting portion 51, a bearing portion 52 and a pivot seat 53, the mounting portion 51 is located at the rear side of the pivot portion 41, the bearing portion 52 is located at the front side of the pivot portion 41, the lower portion of the bearing portion 52 abuts against the first base 40, so that the second base 50 can only swing backward but not forward when swinging, the pivot seat 53 is located at the front side of the bearing portion 52, the second base further has a sliding rail 54, and the sliding rail 54 is mounted and fixed on the mounting portion 51.

The first link set includes a first lifting rod 71, an auxiliary rod 72, a first balancing rod 73, a sliding seat 74 and a power assisting rod 75, wherein the bottom end of the first lifting rod 71 is slidably and pivotally arranged on the second base 50, the top end of the first balancing rod is pivotally connected to the third base 60, the bottom end of the auxiliary rod 72 is pivotally connected to the pivot seat 53 of the second base 50, and the top end of the auxiliary rod 72 is pivotally connected to the first lifting rod 71 such that the third base 60 can move up and down relative to the second base 50 when the first lifting rod 71 and the auxiliary rod 72 pivot, more specifically, the bottom end of the first lifting rod 71 is pivotally connected to the sliding seat 74, the sliding seat 74 is slidably arranged on the sliding rail 54 such that the first lifting rod 71 can slide and swing relative to the second base 50, and in other possible embodiments of the present utility model, if the bottom end of the first lifting rod has a protrusion and the second base has a channel, the protrusion of the first lifting rod is slidably and rotatably arranged in the channel of the second base, and the sliding rail and the sliding seat can be omitted. The first balance bar 73 is configured like the first lifting bar 71, the bottom end is pivoted to the sliding seat 74, and the top end is pivoted to the third base 60, so that the first balance bar 73 can support and drive the third base 60 to move along with the first lifting bar 71, so that the third base 60 keeps moving horizontally without tilting or only slightly swinging during lifting, however, if the third base 60 has other mechanisms to assist in keeping moving horizontally or can swing the third base 60, the first balance bar 73 can be omitted, for example, if the top end of the auxiliary bar extends upwards and the tail end is slidably and pivotally arranged on the third base, the balance of the third base can be kept by the auxiliary bar. The auxiliary rod 75 is connected to the auxiliary rod 72 to swing together with the auxiliary rod 72, more specifically, the first link set further includes a pivot shaft 76, both the auxiliary rod 72 and the auxiliary rod 75 are directly connected to the pivot shaft 76, and the pivot shaft 76 is rotatably disposed on the pivot seat 53, and in other possible embodiments of the present disclosure, for example, it is possible to directly connect the auxiliary rod 75 to the auxiliary rod 72, or directly or indirectly connect the auxiliary rod 75 to the first lifting rod 71.

The lifting telescopic rod 80 has one end pivoted to the auxiliary rod 75 and the other end pivoted to the pivot seat 42, and when the lifting telescopic rod 80 moves telescopically, the auxiliary rod 72 can be pushed to swing by the auxiliary rod 75, and the auxiliary rod 72 and the first lifting rod 71 can be further driven to swing pivotally to enable the third base 60 to move vertically, and the auxiliary rod 75 can provide a preferred pivot position of the lifting telescopic rod 80 to output a preferred moment to the auxiliary rod 72, and in other possible embodiments of the utility model, the lifting telescopic rod can also be directly pivoted to the auxiliary rod to remove the auxiliary rod, or the lifting telescopic rod can be pivoted to other parts of the first link group, such as the first lifting rod, and still can drive the first lifting rod and the auxiliary rod to swing pivotally when the lifting telescopic rod moves telescopically; in addition, if the top end of the lifting telescopic rod is pivoted or connected to the third base directly or indirectly through other mechanisms, the lifting telescopic rod may drive the third base to move up and down, and at this time, the first link set may also adopt a sliding rail extending vertically or obliquely up and down, so long as the third base can move up and down relative to the second base.

Referring to fig. 7 to 9, the lifting telescopic rod 80 can move telescopically among a first lifting length, a middle lifting length and a second lifting length, wherein the middle lifting length is between the first lifting length and the second lifting length. As shown in fig. 7, when the lifting/lowering telescopic rod 80 is at the intermediate lifting/lowering length, the third base 60 is located at the lowered position, and the slide 74 is located at the rear end of the slide rail 54, and the third base 60 cannot be lowered any further. As shown in fig. 7 and 8, when the lifting/lowering telescopic rod 80 stretches from the middle lifting/lowering length to the first lifting/lowering length, the lifting/lowering telescopic rod 80 pushes the booster rod 75, and further drives the booster rod 72 to pivot with the first lifting/lowering rod 71, and the slide carriage 74 moves forward along the slide rail 54, so that the third base 60 moves upward toward the lifting position. As shown in fig. 7 and 9, when the lifting/lowering telescopic rod 80 is retracted from the middle lifting/lowering length to the second lifting/lowering length, the third base 60 is located at the lowered position and cannot be lowered any further, and the third base 60 pushes the second base 50 by the pivot shaft 76 and the pivot seat 53, and the slide seat 74 and the slide rail 54, so that the second base 50 swings backward.

Referring to fig. 4 to 6, the fourth base 90 is located above the third base 60, the fourth base 90 is configured to fix the seat portion, the second link set is connected between the fourth base 90 and the third base 60, so that the fourth base 90 can swing relative to the third base 60, in detail, the second link set includes a second lifting rod 121 and a second balance rod 122, the second lifting rod 121 and the second balance rod 122 are pivoted to the third base 60 and the fourth base 90 respectively, the second lifting rod 121, the fourth base 90, the second balance rod 122 and the third base 60 form a planar four-bar mechanism, so that the fourth base 90 can swing close to or far from the third base 60, but if the fourth base 90 is pivoted to the third base 60, the second link set is omitted, the fourth base 90 can still have the capability of swinging relative to the third base, and cannot be omitted. The fourth base 90 has a pivot portion 91 and a limiting portion 92 at a rear side thereof.

The sub-base 100 is pivotally connected to the pivot portion 91 of the fourth base 90 and is located at the rear side of the fourth base, and the sub-base 100 extends upward to have a seat back bracket 101 for fixing the seat back portion. The sub base 100 has an abutment seat 102, the abutment seat 102 will either approach and abut against the limit stop 92 or be away from and not abut against the limit stop 92 when the sub base 100 is pivoted relative to the fourth base 90.

The standing-up telescopic rod 110 is pivotally connected to the third base 60 and the sub-base 100, and can push the sub-base 100 and/or the fourth base 90 to swing when the standing-up telescopic rod 110 moves in a telescopic manner. Referring to fig. 10 to 12, the standing-up telescopic rod 110 can move telescopically among a first standing-up length, a middle standing-up length and a second standing-up length, wherein the middle standing-up length is between the first standing-up length and the second standing-up length. As shown in fig. 10 and 11, when the lift telescopic rod 110 moves telescopically between the first lift length and the middle lift length, the fourth base 90 abuts against the third base 60 or the second link group below as shown in fig. 6 and cannot swing downwards, and the lift telescopic rod 110 drives the sub-base 100 to swing relative to the fourth base 90, so that the swing of the sub-base 100 can further control the inclination and the erection of the seat back due to the fact that the seat back part is fixed on the sub-base 100. As shown in fig. 11, when the lift telescoping rod is in the intermediate lift length, the sub-base 100 swings until the abutment seat 102 contacts the abutment stopper 92, and the back of the chair correspondingly assumes an upright posture. As shown in fig. 11 and 12, when the lift telescopic rod 110 is further moved to the second lift length from the middle lift length, since the sub-base 100 abuts against the limiting portion 92 so that the sub-base 100 cannot swing upward with respect to the fourth base 90, the lift telescopic rod 110 is extended to the second lift length so that the sub-base 100 pushes the fourth base 90 to swing upward by means of the limiting portion 92 so that the fourth base 90 swings with respect to the third base 60, and since the seat portion is fixed to the fourth base 90, the forward tilting swing of the fourth base as shown in fig. 12 will provide a use effect for assisting the lift.

Referring to fig. 4 to 6, the footrest link assembly 130 and the footrest telescopic link 140 are disposed on the third base, the footrest link assembly 130 can be fixed by the footrest portion 30, and the footrest telescopic link 140 drives the link mechanism of the footrest link assembly 130 to translate and swing, so as to push the footrest portion 30 to extend, expand and retract.

The electric chair base can achieve the use function of assisting in rising and adjusting the height of the chair surface. Referring to fig. 6 and 13, the lifting telescopic rod 80 can be extended to drive the first lifting rod 71 and the auxiliary rod 72 of the first link assembly to pivot, drive the third base 60 to lift, and lift the seat portion 10, the back portion 20 and the footrest portion 30 disposed above the third base 60 to adjust the height. Referring to fig. 13 and 14, the lifting telescopic rod 110 can be extended to drive the sub-base 100 and the fourth base 90 to tilt forward, so that the seat portion 10 and the back portion 20 tilt forward to assist the user to stand up. Because the functions of adjusting the height and assisting the rising are respectively from the lifting telescopic rod to drive the third base to lift and the lifting telescopic rod to drive the fourth base to swing, the height of the third base can not influence the swing of the fourth base and the function of assisting the rising is provided, and the chair seat 10 can be adjusted to any height so as to start the use function of assisting the rising, so that the height of the chair seat can be adjusted according to the requirements of a user.

In addition to the above functions, the electric chair base of the present utility model can also provide a lying posture, even commonly called "gravity-free chair", referring to fig. 15, the lifting telescopic rod 110 can be shortened to drive the auxiliary base 100 to tilt backward, so that the chair back 20 can tilt backward, and the leaning linkage 130 can be driven by the leaning telescopic rod 140 to push and spread the leaning part 30 forward, so that the user can lie down. Referring to fig. 15 and 16, the lifting/lowering telescopic rod 80 can be further shortened to drive the second base 50 to tilt backward for further lying, so that a more comfortable lying posture can be obtained.

It should be noted that the electric chair has the functions of adjusting the height, assisting in rising and lying down as a "gravity-free chair", but if only the functions of adjusting the height and tilting the seat are needed, the parts such as the second link group, the fourth base, the auxiliary base, the rising telescopic rod, etc. are removed and omitted, and the seat part is directly or indirectly arranged on the third base, which is also a possible embodiment of the present utility model.

Referring to fig. 17 and 18, in another embodiment of the present utility model, the first lifting rod, the auxiliary rod and the first balancing rod in the first link set may be turned upside down instead of affecting the above-mentioned usage function. In more detail, the top end of the first lifting rod 71 is slidably and pivotally disposed on the third base 60, the bottom end is pivotally connected to the pivot seat 53 of the second base 50, the top end of the auxiliary rod 72 is pivotally connected to the third base 60, and the bottom end is pivotally connected to the first lifting rod 71, such that the third base 60 can move up and down relative to the second base 50 when the first lifting rod 71 and the auxiliary rod 72 pivot, further, the top end of the first lifting rod 71 is pivotally connected to the sliding seat 74, the third base 60 has the sliding rail 61, and the sliding seat 74 is slidably disposed on the sliding rail 61, such that the first lifting rod 71 can slide and swing relative to the third base 60. The first balance bar 73 is configured as the first lifting bar 71, the top end is pivoted to the sliding seat 74, and the bottom end is pivoted to the second base 50, so that the first balance bar 73 can support and drive the third base 60 to move along with the first lifting bar 71, and the third base 60 keeps translating without tilting or only slightly swinging during lifting movement. The power-assisted rod 75 is connected to the first lifting rod 71 and swings together with the first lifting rod 71, the lifting telescopic rod 80 is pivoted to the pivoting seat 42 of the power-assisted rod and the second base, and when the lifting telescopic rod 80 stretches and contracts, the power-assisted rod 75 can drive the first lifting rod 71 to pivot, so as to drive the third base 60 to lift, or after the third base 60 descends to a descending position and cannot descend any further, the third base 60 pushes the second base 50 to enable the second base 50 to tilt backwards and pivot, so that the same use functions as those of the previous embodiment are realized.

Summarizing the above description, the utility model provides the functions of adjusting the height and tilting the chair surface by the lifting telescopic rod and the related components in the electric chair base, the mechanism is simple and has various functions, and if the lifting telescopic rod and the related components are added, the lifting telescopic rod and the related components are more complete and have the functions of adjusting the height, assisting the lifting and lying of the gravity-free chair, the mechanism is simple and the actions of the components are simple and easy to understand, the utility model is beneficial to a control system and related operation settings, can effectively control the manufacturing cost, and has great market value.

Claims (10)

1. A powered chair base comprising:

A first base;

The second base is arranged on the first base and can swing around a horizontal axis relative to the first base;

A third base;

The first connecting rod group is connected with the second base and the third base, so that the third base can move up and down between a descending position close to the second base and a ascending position far away from the second base;

The lifting telescopic rod is connected with the third base and one of the first connecting rod groups and the first base, can move in a telescopic mode among a first lifting length, a middle lifting length and a second lifting length, the middle lifting length is between the first lifting length and the second lifting length, the lifting telescopic rod drives the third base to move in a lifting mode between the lifting position and the descending position when moving in a telescopic mode between the first lifting length and the middle lifting length, the third base is located at the descending position when the lifting telescopic rod is located at the middle lifting length, and the second base swings relative to the first base around the horizontal axis when the lifting telescopic rod moves in a telescopic mode between the middle lifting length and the second lifting length.

2. The chair base of claim 1, wherein the first link assembly comprises a first lifting rod and an auxiliary rod, wherein one end of the first lifting rod is slidably and pivotally arranged on one of the second base and the third base, the auxiliary rod is pivotally connected to the one of the second base and the third base, the other end of the first lifting rod is pivotally connected to the other of the second base and the third base, and the third base can move up and down between the lowered position and the raised position when the first lifting rod and the auxiliary rod pivot.

3. The chair base of claim 2, wherein said first linkage further comprises a first balance bar, one end of said first balance bar is slidably and pivotally mounted to one of said second base and said third base along with said first lifting bar, and the other end is pivotally connected to the other of said second base and said third base.

4. The chair base of claim 2, wherein one of the second base and the third base comprises a sliding rail, the first link assembly comprises a sliding seat slidably disposed on the sliding rail, and the first lifting rod is pivotally connected to the sliding seat.

5. The chair base of claim 3, wherein one of the second base and the third base comprises a sliding rail, the first link assembly comprises a sliding seat slidably disposed on the sliding rail, the first lifting rod is pivotally connected to the sliding seat, and the first balance rod is pivotally connected to the sliding seat.

6. The chair base of claim 2, wherein the first linkage further comprises a booster rod connected to one of the booster rod and the first lifting rod for swinging together, wherein one end of the lifting rod is pivoted to the booster rod, and the other end of the lifting rod is pivoted to the first base.

7. The chair base of any one of claims 1 to 6, further comprising a fourth base, a sub-base and a lift telescoping rod, wherein the fourth base is capable of swinging relative to the third base, the fourth base has a limiting portion, the sub-base is pivotally connected to the fourth base to be capable of pivotally abutting or not abutting the limiting portion relative to the fourth base, the lift telescoping rod is connected to the third base and the sub-base, the lift telescoping rod is capable of telescoping movement between a first lift length, a middle lift length and a second lift length, the middle lift length is between the first lift length and the second lift length, the sub-base is caused to swing relative to the fourth base when the lift telescoping rod is in the middle lift length, the sub-base abuts the limiting portion when the lift telescoping rod is in the middle lift length, and the sub-base abuts the fourth base when the lift telescoping rod is moved from the middle lift length to the second sub-lift length.

8. The chair base of claim 7, further comprising a second linkage comprising a second lifting rod and a second balance rod, wherein the second lifting rod is pivotally connected to the third base and the fourth base, the second balance rod is pivotally connected to the third base and the fourth base, and the fourth base can swing close to or away from the third base by forming a four-bar linkage with the third base, the second lifting rod, the fourth base and the second balance rod.

9. An electric chair comprising an electric chair base as claimed in any one of claims 1 to 6, further comprising a seat portion and a back portion, wherein the seat portion and back portion are located above the third base and are moved by the third base when the third base is moved.

10. An electric chair comprising the electric chair base according to any one of claims 7 to 8, further comprising a seat portion and a chair back portion, wherein the seat portion is disposed on the fourth base to move therewith, and the chair back portion is disposed on the sub-base to move therewith.