Footrest lifting and angle adjustment mechanism of an electric wheelchair

Abstract

A footrest lifting and angle adjustment mechanism for an electric wheelchair, comprising an upper fixed block, a first push rod, and a second push rod, wherein the upper fixed block is attached to the front end of the wheelchair frame, and wherein the first push rod comprises a first housing and the second push rod comprises a second housing, and wherein the upper end of the second housing and the first housing are each pivotally attached to the upper fixed block, and wherein the second housing is located on the front side of the first housing, and wherein a first sliding tube of the first push rod is pivotally attached to a section of the second housing facing away from the upper end, and wherein a footrest is attached to a second sliding tube of the second push rod, and wherein the first push rod is arranged at an angle.and wherein the articulated joint between the first housing and the upper fixed block is located on the rear side of the articulated joint between the first sliding tube and the second housing, and wherein the first sliding tube of the first push rod changes its length so that the second push rod drives the footrest to an upward and downward rotation around the upper end of the second housing, while the second sliding tube of the second push rod changes its length so that the distance between the footrest and the upper fixed block lengthens or shortens, characterized in that a drive motor, a screw, a nut and a guide tube are arranged in the second housing, wherein one end of the second sliding tube is fastened with the nut, while the other end of the second sliding tube extends to the outside of the second housing, and wherein a protective hood is arranged outside the second push rod,and wherein several first guide slots are formed on a tube wall of the guide tube arranged along the axis of the guide tube, and wherein the nut comprises a nut body mounted on the screw, a nut fastening block located outside the guide tube, a nut connecting block for making a connection between the nut fastening block and the nut body, and wherein the nut connecting block fits into the first guide slot, and wherein the nut fastening block is attached to the protective cap, and wherein the nut moves along the screw to drive the protective cap to move along the screw, and wherein the protective cap comprises a mask and two fixing columns arranged opposite each other, with a nut fastening block arranged on the left and right side of the nut body,and wherein a first guide slot is provided on the left and right side wall of the guide tube, and wherein the mask is attached between the two fixing columns.

Description

TECHNICAL AREA

[0001] The present invention relates to a footrest lifting and angle adjustment mechanism of an electric wheelchair. STATE OF THE ART

[0002] At the front of an electric wheelchair, a footrest is attached to support the foot. However, the footrests of currently available electric wheelchairs are mostly fixed and immobile, making it difficult for users to find a more comfortable sitting or reclining position. Since people have different leg lengths, fixed, immobile footrests limit the usability of the electric wheelchair.

[0003] US 8186695 B2 discloses a wheelchair with a chassis comprising a lower and an upper chassis section pivotally connected to each other via a substantially horizontal axis. The lower chassis section consists of two load-bearing longitudinal members oriented parallel to the direction of travel, spaced apart by at least one transverse member perpendicular to the direction of travel. The rear wheels are detachably mounted at the intersections of the transverse member with the longitudinal members. Front wheels, pivotable about a vertical axis, may be attached near or as part of the pivot connection. The seat is slidably mounted on the upper chassis section and is also pivotable about a horizontal axis. US3618968 A relates to a wheelchair with a basic structure consisting of two parallel lower load-bearing members and vertical supports. The rectangular seat frame is height-adjustable via guide elements along the supports.A swiveling backrest and leg rest are attached to the seat. Main and swivel casters are mounted on the base structure. US 20060086202 A1 discloses a movable leg rest with a first element pivotally connected to a base frame. A second element is telescopically guided within the first element. A motor-driven spindle drive with two internal threaded elements moves the first element via a connection and rotates it relative to the base frame. Simultaneously, the second element is moved linearly within the first element. CONTENT OF THE PRESENT INVENTION

[0004] An objective of the present invention is to provide a footrest lifting and angle adjustment mechanism for an electric wheelchair, with which an adjustment of the footrest position can be achieved to improve comfort during use.

[0005] To achieve the above objective, the present invention employs the following technical solution: a footrest lifting and angle adjustment mechanism for an electric wheelchair, comprising an upper fixed block, a first push rod, and a second push rod, wherein the upper fixed block is attached to the front end of the wheelchair frame, and wherein the first push rod comprises a first housing and the second push rod comprises a second housing, and wherein the upper end of the second housing and the first housing are each pivotally attached to the upper fixed block, and wherein the second housing is located on the front side of the first housing, and wherein a first sliding tube of the first push rod is pivotally attached to a section of the second housing facing away from the upper end, and wherein a footrest is attached to a second sliding tube of the second push rod, and wherein the first push rod is arranged at an inclination.and wherein the articulated joint between the first housing and the upper fixed block is located on the rear side of the articulated joint between the first sliding tube and the second housing, and wherein the first sliding tube of the first push rod changes its length so that the second push rod drives the footrest to an up-and-down rotation around the upper end of the second housing, while the second sliding tube of the second push rod changes its length so that the distance between the footrest and the upper fixed block lengthens or shortens.

[0006] When using a wheelchair according to the present invention, the footrest rotates forwards, backwards, upwards and downwards by means of the first push rod, while the distance between the footrest and the wheelchair frame is adjustable by means of the second push rod, so that the wheelchair can accommodate various sitting and even lying gestures of users to improve user comfort.

[0007] According to the present invention, a drive motor, a screw, a nut, and a guide tube are arranged in the second housing, wherein one end of the second sliding tube is fastened with the nut, while the other end of the second sliding tube extends to the outside of the second housing, and wherein a protective hood is arranged outside the second sliding tube, and wherein several first guide slots are formed on a tube wall of the guide tube arranged along the axis of the guide tube, and wherein the nut comprises a nut base body mounted on the screw, a nut fastening block located outside the guide tube, a nut connecting block for establishing a connection between the nut fastening block and the nut base body, and wherein the nut connecting block fits into the first guide slot, and wherein the nut fastening block is fastened with the protective hood.and wherein the nut moves along the screw to drive the protective cap to move along the screw.

[0008] To prevent the user's trousers from being wrapped in the second push rod, a protective hood is provided in the present invention; the protective hood prevents the second push rod from moving, and at the same time the protective hood can move with the movement of the footrest, thereby achieving a better safety of the present invention.

[0009] According to the present invention, the protective hood comprises a mask and two opposing fixing columns, wherein a nut fixing block is arranged on each side of the nut base body, and wherein a first guide slot is provided on each side wall of the guide tube, and wherein the mask is fixed between the two fixing columns. The above arrangement prevents the protective hood from wobbling from side to side, thus improving the stability of the present invention.

[0010] Preferably, a nut positioning block is arranged on the nut connection block, wherein the pipe wall of the guide tube is confined between the nut positioning block and the nut fastening block. The above arrangement further prevents the protective hood from oscillating, thus providing the structure of the present invention with greater stability.

[0011] Preferably, a matching guide projection and a second guide slot are formed between the inner wall of the nut fastening block and the outer wall of the guide tube. In the present invention, a guide projection or a second guide slot is arranged on the outer wall of the guide tube, making the guide tube easier to process and simultaneously simplifying the guiding movement of the nut according to the present invention.

[0012] Preferably, several internal projections are arranged on the inner wall of the nut mounting block, wherein the radial section of the outer edge of the internal projection extending along the screw is arcuate, and wherein the arcuate surface of the internal projection and the outer wall of the guide tube come into contact. With the above arrangement, the contact area between the nut and the guide tube is reduced in order to decrease the frictional force between the nut and the guide tube, thus simplifying the assembly of the guide tube and the nut.

[0013] Preferably, several elastic elements are arranged between the nut connection block and the inner wall of the guide tube. Each elastic element comprises a housing, a steel bead, and a spring. The housing is attached to the nut connection block, and the steel bead, under the action of the spring, bears against the inner wall of the guide tube. This arrangement makes the nut more stable, preventing wobble. Since the elastic element is attached to the nut, the nut can be directly formed by injection molding, simplifying processing and reducing manufacturing costs.

[0014] Preferably, the guide tube is formed by a front half-tube and a rear half-tube, wherein an upper fixed seat and a lower cover plate are arranged at each axial end of the guide tube, and wherein the front half-tube and the rear half-tube are fastened by a fastening element between the upper fixed seat and the lower cover plate, and wherein the first guide slot is formed between the front half-tube and the rear half-tube. The above arrangement simplifies the manufacture of the guide tube of the present invention, while also facilitating the assembly of the guide tube and the nut, thereby reducing the manufacturing costs of the wheelchair of the present invention.

[0015] Preferably, the nut mounting block comprises a left nut mounting block located on the left side of the guide tube, a right nut mounting block located on the right side of the guide tube, and a front nut mounting block located on the front side of the guide tube, wherein the left nut mounting block, the right nut mounting block, and the front nut mounting block are connected to each other to form a U-shaped structure, and wherein the left nut mounting block and the right nut mounting block are each secured by a fixing column, and wherein the mask is attached to the front side of the front nut mounting block. With the above arrangement, the movement of the nut and the protective cover of the present invention becomes more stable.

[0016] Preferably, the upper end of the first housing is pivotally attached to the upper fixed block to form a first pivot point, while the upper end of the second housing is pivotally attached to the upper fixed block to form a second pivot point, wherein the vertical position of the second pivot point is higher than that of the first pivot point, and wherein the lower end of the first sliding tube of the first push rod is pivotally attached to the second housing to form a third pivot point, and wherein the maximum stroke length of the first push rod is La, and wherein the longitudinal distance between the first pivot point and the second pivot point is Lb, and wherein the vertical distance between the first pivot point and the second pivot point is Lc.and wherein, in the case of a vertically oriented second sliding tube of the second push rod, the longitudinal distance between the third joint connection point and the second joint connection point is Ld and the vertical distance between the second joint connection point and the third joint connection point is Le, (Lb-Ld), 2 +(Lc+L e) 2 =La 2 With the above arrangement, the second push rod of the present invention can rotate forwards and upwards until it reaches the horizontal state, in order to extend the replacement range of the wheelchair of the present invention.

[0017] In the present invention, the footrest position is adjustable, and the wheelchair has a wider range of uses; at the same time, the present invention has a safer, more stable structure. List of characters • Fig. Figure 1 shows a view of the present invention in use. • Fig. Figure 2 shows another view of the present invention in use. • Fig. Figure 3 shows another view of the present invention in use. • Fig. Figure 4 shows a schematic structural view of a second push rod in a horizontal state according to the present invention. • Fig. Figure 5 shows a cross-sectional view of the present invention. • Fig. Figure 6 shows another cross-sectional view of the present invention. • Fig. Figure 7 shows a schematic structural view of a mother of the present invention. • Fig. Figure 8 shows a schematic structural view of a guide tube of the present invention. DETAILED DESCRIPTION

[0018] The present invention will be explained in more detail below in connection with figures and detailed embodiments.

[0019] As in Fig. 1 to Fig. Figure 4 shows a footrest lifting and angle adjustment mechanism for an electric wheelchair according to the present invention, comprising an upper fixed block 1, a first push rod 2, and a second push rod 3, wherein the upper fixed block 1 is attached to the front end of the wheelchair frame, and wherein the first push rod 2 comprises a first housing 21 and the second push rod 3 comprises a second housing 31, and wherein the upper end of the second housing 31 and the upper end of the first housing 21 are each pivotally attached to the upper fixed block 1, and wherein the second housing 31 is located on the front side of the first housing 21, and wherein a first sliding tube 22 of the first push rod 2 is pivotally attached to the lower end of the second housing 31, and wherein a footrest 4 is attached to a second sliding tube 32 of the second push rod 3, and wherein the first push rod 2 is arranged at an inclination.and wherein the articulated joint between the first housing 21 and the upper fixed block 1 is located on the rear side of the articulated joint between the first sliding tube 22 and the second housing 31, and wherein the first sliding tube 22 of the first push rod 2 changes its length so that the second push rod 3 drives the footrest 4 to an upward and downward rotation about the upper end of the second housing 31, while the second sliding tube 32 of the second push rod 3 changes its length so that the distance between the footrest 4 and the upper fixed block 1 lengthens or shortens.

[0020] The upper end of the first housing 21 is pivotally attached to the upper fixed block 1 to form a first pivot point 11, while the upper end of the second housing 31 is pivotally attached to the upper fixed block 1 to form a second pivot point 12, wherein the vertical position of the second pivot point 12 is higher than that of the first pivot point 11, and wherein the lower end of the first sliding tube 22 of the first push rod 2 is pivotally attached to the second housing 31 to form a third pivot point 13, and wherein the maximum stroke length of the first push rod 2 is La, and wherein the longitudinal distance between the first pivot point 11 and the second pivot point 12 is Lb, and wherein the vertical distance between the first pivot point 11 and the second pivot point 12 is Lc.and where, in the case of a vertically oriented second sliding tube 32 of the second push rod 3, the longitudinal distance between the third joint connection point 13 and the second joint connection point 12 is Ld and the vertical distance between the second joint connection point 12 and the third joint connection point 13 is Le, then (Lb-Ld)2 +(Lc+Le)2 =La2.,

[0021] As in Fig. 5 to Fig. As shown in Figure 8, a drive motor, a screw 5, a nut 6, and a guide tube 7 are arranged in the second housing 31, wherein one end of the second sliding tube 32 is fastened with the nut 6, while the other end of the second sliding tube 32 extends to the outside of the second housing 31, and wherein a protective hood 8 is arranged outside the second push rod 3, and wherein several first guide slots 70 are formed on a tube wall of the guide tube 7 arranged along the axis of the guide tube 7, and wherein the nut 6 comprises a nut base body 61 mounted on the screw 5, a nut fastening block 62 located outside the guide tube 7, a nut connecting block 63 for establishing a connection between the nut fastening block 62 and the nut base body 61, and wherein the nut connecting block 63 fits into the first guide slot 70, and wherein the nut fastening block 62 is fastened with the protective hood 8.and wherein the nut 6 moves along the screw 5 to drive the protective hood 8 to move along the screw 5.

[0022] As in Fig. 2 and Fig. As shown in Figure 8, the guide tube 7 is formed by a front half-tube 71 and a rear half-tube 72, wherein an upper fixed seat 73 and a lower cover plate 74 are arranged at each of the axial ends of the guide tube 7, and wherein the front half-tube 71 and the rear half-tube 72 are fastened by a fastening element between the upper fixed seat 73 and the lower cover plate 74, and wherein there is a certain distance between the front half-tube 71 and the rear half-tube 72 in order to form the first guide slot 70.

[0023] As in Fig. 5 to Fig. As shown in Figure 7, the protective hood 8 comprises a mask 81 and two fixing columns 82 arranged opposite each other, wherein a nut fixing block 62 is arranged on each left and right side of the nut base body 61, and wherein a first guide slot 70 is provided on each left and right side wall of the guide tube 7, and wherein the mask 81 is fixed between the two fixing columns 82.The nut fastening block 62 comprises a left nut fastening block 621 located on the left side of the guide tube 7, a right nut fastening block 622 located on the right side of the guide tube 7, and a front nut fastening block 623 located on the front side of the guide tube 7, wherein the left nut fastening block 621, the right nut fastening block 622, and the front nut fastening block 623 are formed integrally to form a U-shaped structure, and wherein the left nut fastening block 621 and the right nut fastening block 622 are each fastened by a fastening element with a fixing column, and wherein the mask 81 is fastened by the fastening element on the front side of the front nut fastening block 623.

[0024] As in Fig. 5 to Fig.As shown in Figure 7, a nut positioning block 631 is arranged on the nut connection block 63, wherein the tube wall of the guide tube 7 is confined between the nut positioning block 631 and the nut fastening block 62. A matching guide projection 64 and a second guide slot 75 are formed between the inner wall of the nut fastening block 62 and the outer wall of the guide tube 7. Several inner projections 65 are arranged on the inner wall of the nut fastening block 62, wherein the radial section of the outer edge of the inner projection 65 extending along the screw 5 is arcuate, and wherein the arcuate surface of the inner projection 65 and the outer wall of the guide tube 7 come into contact.Between the nut connection block 63 and the inner wall of the guide tube 7 several elastic elements 9 are arranged, wherein the elastic element 9 comprises a housing of the elastic element 91, a steel bead 92 and a spring 93, and wherein the housing of the elastic element 91 is attached to the nut connection block 63, and wherein the steel bead 92 of the elastic element 9, under the action of the spring 93, abuts the inner wall of the guide tube.

[0025] When using a wheelchair according to the present invention, the footrest rotates forwards, backwards, upwards, and downwards by means of the first push rod, while the distance between the footrest and the wheelchair frame is adjustable by means of the second push rod. The second push rod according to the present invention can rotate to a horizontal position under the action of the first push rod, so that the wheelchair accommodates various sitting and even reclining positions for the user, thus improving user comfort. With the present invention, the footrest position is adjustable, and the wheelchair has a wider range of uses. At the same time, the present invention provides a safer and more stable structure.

Claims

[1] Footrest lifting and angle adjustment mechanism of an electric wheelchair, comprising an upper fixed block, a first push rod and a second push rod, the upper fixed block being attached to the front end of the wheelchair frame, the first push rod comprising a first housing and the second push rod comprising a second housing, the upper end of the second housing and the first housing being pivotally attached to the upper fixed block, the second housing being located on the front side of the first housing, a first sliding tube of the first push rod being pivotally attached to a section of the second housing facing away from the upper end, a footrest being attached to a second sliding tube of the second push rod, and the first push rod being inclinedand wherein the articulated joint between the first housing and the upper fixed block is located on the rear side of the articulated joint between the first sliding tube and the second housing, and wherein the first sliding tube of the first push rod changes its length so that the second push rod drives the footrest to an up-and-down rotation around the upper end of the second housing, while the second sliding tube of the second push rod changes its length so that the distance between the footrest and the upper fixed block lengthens or shortens, , characterized by, that in the second housing a drive motor, a screw, a nut and a guide tube are arranged, wherein one end of the second sliding tube is fastened to the nut, while the other end of the second sliding tube extends to the outside of the second housing, and wherein a protective hood is arranged outside the second sliding tube, and wherein several first guide slots are formed on a tube wall of the guide tube arranged along the axis of the guide tube, and wherein the nut comprises a nut body mounted on the screw, a nut fastening block located outside the guide tube, a nut connecting block for making a connection between the nut fastening block and the nut body, and wherein the nut connecting block fits into the first guide slot, and wherein the nut fastening block is fastened to the protective hood, and wherein the nut moves along the screw,to drive the protective hood to move along the screw, and that the protective hood comprises a mask and two fixing columns arranged opposite each other, wherein a nut fixing block is arranged on the left and right sides of the nut body, and wherein a first guide slot is provided on the left and right side walls of the guide tube, and wherein the mask is fixed between the two fixing columns. [2] Footrest lifting and angle adjustment mechanism of an electric wheelchair according to claim 1, characterized by , that a nut positioning block is arranged on the nut connection block, wherein the pipe wall of the guide tube is confined between the nut positioning block and the nut fastening block. [3] Footrest lifting and angle adjustment mechanism of an electric wheelchair according to claim 1, characterized by, that a matching guide projection and a second guide slot are formed between the inner wall of the nut mounting block and the outer wall of the guide tube. [4] Footrest lifting and angle adjustment mechanism of an electric wheelchair according to claim 1, characterized by , that several internal projections are arranged on the inner wall of the nut fastening block, wherein the radial section of the outer edge of the internal projection running along the screw is arranged in an arc shape, and wherein the arc shape of the internal projection and the outer wall of the guide tube come into contact. [5] Footrest lifting and angle adjustment mechanism of an electric wheelchair according to claim 1, characterized by, that several elastic elements are arranged between the nut connection block and the inner wall of the guide tube, wherein the elastic element comprises a housing of the elastic element, a steel bead and a spring, and wherein the housing of the elastic element is attached to the nut connection block, and wherein the steel bead of the elastic element, under the action of the spring, impacts the inner wall of the guide tube. [6] Footrest lifting and angle adjustment mechanism of an electric wheelchair according to claim 1, characterized by, that the guide tube is formed by a front half-tube and a rear half-tube, wherein an upper fixed seat and a lower cover plate are arranged at each of the axial ends of the guide tube, and wherein the front half-tube and the rear half-tube are fastened by a fastening element between the upper fixed seat and the lower cover plate, and wherein the first guide slot is formed between the front half-tube and the rear half-tube. [7] Footrest lifting and angle adjustment mechanism of an electric wheelchair according to claim 1, characterized by, that the nut fastening block comprises a left nut fastening block located on the left side of the guide tube, a right nut fastening block located on the right side of the guide tube and a front nut fastening block located on the front side of the guide tube, wherein the left nut fastening block, the right nut fastening block and the front nut fastening block are connected to each other to form a U-shaped structure, and wherein the left nut fastening block and the right nut fastening block are each fastened with a fixing column, and wherein the mask is fastened on the front side of the front nut fastening block. [8] Footrest lifting and angle adjustment mechanism of an electric wheelchair according to claim 1, characterized by, that the upper end of the first housing is pivotally attached to the upper fixed block to form a first pivot point, while the upper end of the second housing is pivotally attached to the upper fixed block to form a second pivot point, wherein the vertical position of the second pivot point is higher than that of the first pivot point, and wherein the lower end of the first sliding tube of the first pushrod is pivotally attached to the second housing to form a third pivot point, and wherein the maximum stroke length of the first pushrod is La, and wherein the longitudinal distance between the first pivot point and the second pivot point is Lb, and wherein the vertical distance between the first pivot point and the second pivot point is Lc,and wherein, in the case of a vertically oriented second sliding tube of the second push rod, the longitudinal distance between the third joint connection point and the second joint connection point is Ld and the vertical distance between the second joint connection point and the third joint connection point is Le, (Lb-Ld) , 2 +(Lc+Le) 2 =La 2 .

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