輔助站立輪椅 （文獻(xiàn)翻譯) 11輔助輪椅的設(shè)計(jì)美國(guó)專利4519649摘要:輪椅改良設(shè)計(jì)使在身體支撐于一個(gè)主框架上，可以使坐姿改變而無(wú)需使用外部的升降力達(dá)到獨(dú)立的站立姿態(tài)。輪椅包括配套驅(qū)動(dòng)輪、輔助輪和機(jī)構(gòu)的支撐，腰部支撐部件和靠背部件彼此形成的主結(jié)構(gòu)。前部的主結(jié)構(gòu)和腰部支撐部件的尖端部分設(shè)一個(gè)支點(diǎn)，并擴(kuò)展部件的支撐與支撐腰部支撐的部件，作為支撐點(diǎn)之間的中間點(diǎn)的主要結(jié)構(gòu)和腰部支點(diǎn)支撐部件。依靠推輪椅使用者的力量（身體抬起，使用者通過(guò)他或她的上肢的力量）和擴(kuò)展的力量。1 輪椅的各部件: 1.一個(gè)主框架配套驅(qū)動(dòng)輪和輔助輪;身體的支撐框架包括下肢軸互聯(lián)支撐構(gòu)件，腰部支撐構(gòu)件和靠背的構(gòu)件，該主結(jié)構(gòu)的身體支撐架被作為獨(dú)立的結(jié)構(gòu)組成，前端部分的腰部支撐構(gòu)件是身體支撐架軸連接前端部分支點(diǎn)的主體。裝有氣彈簧的一端，氣彈簧的軸連接到主體上，并在其另一端連接軸及其活塞桿腰部支撐部件和架等機(jī)構(gòu)的支撐，擴(kuò)展和回縮氣彈簧的原因，腰部支撐構(gòu)件旋轉(zhuǎn)支點(diǎn)主體。鎖定在可操作的連接，空氣為鎖定彈簧的氣體在任意位置之間的全面伸長(zhǎng)和一個(gè)完全縮回的位置，以便恢復(fù)彈簧在腰部規(guī)定的角度范圍內(nèi)任意角度與水平方面的支撐構(gòu)件其旋轉(zhuǎn)的支點(diǎn)方法，充分伸長(zhǎng)，氣彈簧相應(yīng)的座位和站立身體支撐架所述位置，分別表示完全縮回的位置。2. 其中一個(gè)要求 1 中所示的輪椅，表示鎖定方式包括閥門彈簧接收機(jī)構(gòu)，氣彈簧的操作桿。安裝一個(gè)可操作的雙節(jié)點(diǎn)支撐，操作線進(jìn)行閥門操作桿表示閥門的連接操作桿，其緊握操作桿，從而允許伸長(zhǎng)和收縮的氣彈簧，而釋放操作桿引起鎖定氣彈簧，以免伸長(zhǎng)或收縮。輔助站立輪椅 （文獻(xiàn)翻譯) 223.要求 1 中所示的輪椅，其中腰部支撐構(gòu)件連接下肢支持構(gòu)件，通過(guò)鏈接機(jī)制。 4.主框架作為 3 定義輪椅，其中鏈接機(jī)制，腰部支撐的構(gòu)件，其余構(gòu)件包括一個(gè)平行四邊形的 4 桿的鏈接。5.作為 3 定義輪椅，鏈接機(jī)制，腰部支撐的構(gòu)件，下肢支撐構(gòu)件包括有一個(gè)任意長(zhǎng)度的 4 桿的鏈接機(jī)制。2 說(shuō)明：2.1背景本發(fā)明涉及到了輪椅，這使得它可以與一個(gè)極其有限的或沒(méi)有的功能相結(jié)合，如截癱下肢殘疾人從坐姿改變他或她的姿勢(shì)，以獨(dú)立的姿態(tài)，使用其她推力（升殘疾人身體由他或她的上肢動(dòng)作） ，他或她每天練習(xí)，它的動(dòng)力無(wú)需使用任何外部電源。輪椅是一種所需的覆蓋范圍大幅走相同的議案，并可以作為一種短距離的運(yùn)輸車輛的車輛。因此，輪椅必須有一個(gè)全功能作為日常儀器，運(yùn)動(dòng)功能。這使得它可以為殘疾人開展工作所使用的輪椅。不過(guò)，按照的傳統(tǒng)輪椅，輪椅的使用者只可以做固定的姿勢(shì)工作，但能不能做到可以站立的姿勢(shì)時(shí)的工作，因?yàn)樗蛩氖挚赡懿荒苓_(dá)到很高的位置。近年來(lái)，輪椅使用外接電源（如電機(jī)驅(qū)動(dòng)器使用電池作為動(dòng)力源）為一個(gè)獨(dú)立的機(jī)制已經(jīng)提出了一個(gè)輪椅，這使用戶可以獨(dú)立以站姿的姿態(tài)下工作。然而，這種輪椅涉及的收費(fèi)工作和維護(hù)復(fù)雜的缺點(diǎn)，增加輪椅的重量和輪椅本身有限的多功能性是極其昂貴的。輔助站立輪椅 （文獻(xiàn)翻譯) 442.2 相關(guān)的圖紙F(tuán)IG. 1是一個(gè)側(cè)視圖。根據(jù)本發(fā)明的一個(gè)實(shí)例中的輪椅;輔助站立輪椅 （文獻(xiàn)翻譯) 55FIG. 2圖1的后視圖FIG. 3 是一個(gè)透視圖顯示的狀態(tài)，其中一個(gè)被用來(lái)作為一個(gè)擴(kuò)展部件的氣彈簧;輔助站立輪椅 （文獻(xiàn)翻譯) 66FIG. 4 是一個(gè)圖表，顯示的座位角度（站立的角度）和應(yīng)用于座椅和腳踏板的負(fù)荷之間的關(guān)系3 優(yōu)選實(shí)施的案例：在圖1和圖2，參考圖1代表一個(gè)主體，支撐驅(qū)動(dòng)2和第3輪輔助輪。肘支撐4個(gè)固定上部的主構(gòu)件，每邊1個(gè)。參考5代表身體支撐架肢體較低的支撐部件6，腰部支撐構(gòu)件7和8靠背構(gòu)件組成。這些構(gòu)件是連接相鄰部件彼此之間的相對(duì)回轉(zhuǎn)的方式。一個(gè)腳踏板和著地部件10是固定的低端下肢的支撐構(gòu)件6。 7腰部支撐構(gòu)件的尖端是彎曲的并且弓狀形式和一個(gè)支架11固定弓狀部分，其安裝前部的主框架由一個(gè)支點(diǎn)12 和1?？勘硺?gòu)件8，腰部支撐構(gòu)件7和下肢支撐構(gòu)件6連接兩個(gè)4桿的鏈接到另一個(gè)獨(dú)立的機(jī)構(gòu)，包括身體支撐架5。在這些鏈接，靠背8部件和腰部支撐部件7環(huán)節(jié)是連接 A 和 B 的支點(diǎn)12 1 4桿的平行四邊形鏈接，并鏈接腰部支撐構(gòu)件7和下肢的支撐構(gòu)件6是一個(gè)4桿的鏈路輔助站立輪椅 （文獻(xiàn)翻譯) 77連接的部件，6，7和鏈接 C 至支點(diǎn)12之間的聯(lián)合，并可能有一個(gè)任意的或可選的長(zhǎng)度。這兩個(gè)鏈接機(jī)制是安裝在主體1。一個(gè)氣彈簧作為一個(gè)升縮的部件13中間之間的主體1和腰部支撐構(gòu)件7收縮的彈簧13支撐，可以提高和支持點(diǎn)作為支點(diǎn)12腰部支撐構(gòu)件7 。這氣彈簧是一種利用高壓氣體密封在缸14如圖壓力的一個(gè)彈簧。 部件3啟動(dòng)，并在任意位置停止，活塞和氣缸內(nèi)的活塞連接到一桿15。一個(gè)氣彈簧接收機(jī)構(gòu)16安裝到主體1，而15桿裝有腰部支撐構(gòu)件7。操作一個(gè)閥門的操作按鈕17（以下簡(jiǎn)稱為“鎖定按鈕” ） ，可以通過(guò)遠(yuǎn)程控制操作桿18安裝到手肘支撐成員4。在圖紙上，參考數(shù)字19代表的操作線20是一個(gè)閥門操作桿。當(dāng)操作桿18啟動(dòng)，閥門操作桿20和17閥門的操作按鈕被啟動(dòng)箭頭指示的方向和釋放鎖氣彈簧13。握操作桿18時(shí)被釋放，另一方面，閥操作桿20和17閥門的操作按鈕啟動(dòng)以相反的方向鎖定，即氣彈簧13。在輪椅上，動(dòng)力依靠推輪椅的用戶（推高了用戶的上肢身體力量）和反應(yīng)氣彈簧的力量。用戶可以通過(guò)使用這兩種力的獨(dú)立姿態(tài)。的使用方式如下。輪椅上站起來(lái)，需要先剎車，膝蓋和腰部使用者的身體會(huì)被牢牢地固定皮帶輪椅。準(zhǔn)備完成后，安裝操作桿18肘支撐構(gòu)件4可啟動(dòng)，氣彈簧17鎖定按鈕被壓下，以便打開氣彈簧鎖。在氣彈簧的鎖被釋放的階段，開始動(dòng)作。在這種情況下，用戶把他或她的手的手肘支撐件4，然后推動(dòng)機(jī)構(gòu)，以減少他或她的體重經(jīng)座位15桿氣彈簧，這樣延伸，使氣體反應(yīng)的座位輪椅開始提升。用戶在待機(jī)期間，18桿處在一個(gè)理想的高度，以消除鎖定按鈕17的推力和鎖定氣彈簧。因此，可以固定在那個(gè)位置的座位。要返回從站立的姿勢(shì)到坐姿，首先鎖定氣彈簧被釋放的18桿，并同時(shí)抓住肘部支撐件4用戶會(huì)降低他或她的身體，以能夠使引導(dǎo)他她的體重的座位上。在這種情況下，用戶的重量，克服了氣體反應(yīng)和桿氣彈簧的合力，這樣的座位開始緩慢降低。在這種情況下，用戶可以固定在所需的位置鎖定氣彈簧座椅。以上所述，站立時(shí)腰部支撐構(gòu)件的最大角度相對(duì)水平面為75度，其角度可以很容易地設(shè)置用戶所需的任何值。在站立的的靠背部件8角度可始終保持不變，使鏈接8構(gòu)件和腰部支撐成員7的平行四邊形的4桿的水平。下肢支持成員6部分可以逐步擴(kuò)展方面的腰部支撐構(gòu)件按7，以便它可以對(duì)應(yīng)的伸長(zhǎng)與他或她的膝關(guān)節(jié)他或她的膝蓋以下的部分用戶在伸長(zhǎng)的位置行動(dòng)。這個(gè)伸長(zhǎng)的實(shí)現(xiàn)，因?yàn)橛幸粋€(gè)任意長(zhǎng)度的4桿鏈接腰部支撐部件7和下肢的支撐構(gòu)件6的鏈接。在以上所述的闡述中，延伸的數(shù)量是50毫米，最大的站立，但值可以適當(dāng)調(diào)整，根據(jù)用戶的愿望。俯臥的支撐是站立時(shí)必要，直到腰部支撐部件7變?yōu)橄鄬?duì)水平面的30°，但超過(guò)30°時(shí)，站立只能由氣彈簧的力量來(lái)完成。其他各種調(diào)整，可根據(jù)用戶的重量，通過(guò)適當(dāng)調(diào)整氣彈簧的反應(yīng)，此外，氣彈簧，可輕松更換。圖4底角（獨(dú)立角度的腰部支撐構(gòu)件7）和負(fù)載之間的關(guān)系是一個(gè)圖表，顯示一個(gè)座位和座位之間的角度和負(fù)載 B 腳踏板9。橫坐標(biāo)代表的座位角（度） ，縱負(fù)荷（kgf） 。從輔助站立輪椅 （文獻(xiàn)翻譯) 88圖中可以明顯的看出，主要承擔(dān)用戶的重量座位時(shí)的角度小，是由腳踏板和座椅時(shí)的角度是較大的承載。因此，用戶可以不施加過(guò)多的力量需要保持坐姿或站立的姿勢(shì)。此外，部分是因?yàn)轶w重的載荷，甚至在座位的最高站立時(shí)，用戶可以放心對(duì)背部，并順利的工作在站立姿勢(shì)。雖然是固定的腳踏板和著地部件10下肢支撐構(gòu)件在上述體現(xiàn)6中，用戶可以移動(dòng)，同時(shí)保持獨(dú)立的姿態(tài)，如果還裝有小輪子的輪椅。驅(qū)動(dòng)輪也可能是其操作開關(guān)的電動(dòng)型，安裝操作方便輪椅手肘支撐。雖然是不可折疊的輪椅但它可以改變一個(gè)可折疊的類型納入一個(gè)折疊的機(jī)制。按照本發(fā)明，身體支撐架由下肢支撐構(gòu)件，腰部支撐構(gòu)件和靠背機(jī)構(gòu)8驅(qū)動(dòng)伸長(zhǎng)部件的鏈接機(jī)制的巧妙結(jié)合。因此，輪椅使用者可以很容易地從坐姿改變到一個(gè)獨(dú)立站立的位置，反之亦然。即使當(dāng)用戶承擔(dān)獨(dú)立的姿態(tài)，他或她可以支持身體的支撐框架，使他或她能夠順利地開展工作在獨(dú)立的站姿姿態(tài)。由于用戶可以利用和保持獨(dú)立的姿態(tài)，褥瘡和殘疾人關(guān)節(jié)攣縮與很少或沒(méi)有下肢的功能是可以預(yù)防的。伸縮機(jī)構(gòu)的氣彈簧的使用，使得其持續(xù)并順利地從坐姿改變身體的位置姿態(tài)，反之亦然?？梢栽O(shè)置其位置，并固定在所需的姿態(tài)，更可以使用戶在沒(méi)有任何幫助的情況下的姿勢(shì)轉(zhuǎn)變。此外，從坐姿轉(zhuǎn)移到獨(dú)立的姿態(tài)，反之亦然，因?yàn)槭謩?dòng)都可以生效，本發(fā)明的輪椅操作簡(jiǎn)便，并能消除用戶反復(fù)使用和保養(yǎng)所造成可能的危險(xiǎn)。.輔助站立輪椅 （文獻(xiàn)翻譯) 99WheelchairUnited States Patent 4519649Abstract:A wheelchair is disclosed in which a body support frame pivoted to a main frame can move from a seated posture to a stand-up posture and vice versa without using an external elevating force. The wheelchair includes the main frame for supporting driving wheels and auxiliary wheels and a body support frame formed by interconnecting a lower limb support member, a waist support member and a back rest member to one another. The forward portion of the main frame and the tip portion of the waist support member are turnably supported by a pivot, and an extension member for turnably supporting the waist support member with the pivot as the support point is interposed between the main frame and the waist support member. The motive force for the stand-up operation of the body support frame relies upon the push-up force of the user of the wheelchair (the body lift-up force of the user by his or her upper limbs) and the force of the extension member.1. A wheelchair comprising: a main frame supporting driving wheels and auxiliary wheels;a body support frame including pivotally interconnected lower limb support member, waist support member and backrest member, said main frame and said body support frame being formed as independent structures, a front end portion of said waist support member of said body support frame being pivotally connected to a front end portion of said main frame by pivot means;a pair of elbow supports each fixed to an upper portion of said main frame at respective sides thereof, said waist support member of said body support frame being disposed between said pair of elbow supports in a seating position of said body support frame;a gas spring fitted, at one end thereof, to a gas spring receiver pivotally connected to said main frame, and pivotally connected at its other end by a piston rod thereof to said waist support member of said body support frame such that extension and retraction of said gas spring causes said waist support member to rotate about said pivot means with respect to said main frame; and輔助站立輪椅 （文獻(xiàn)翻譯) 1010locking means in operable connection with said gas spring for locking said gas spring in an arbitrary position between a fully extended and a fully retracted position so as to fix said waist support member at an arbitrary angle with respect to the horizontal within a prescribed angular range of its rotation about said pivot means, said fully extending and fully retracted positions of said gas spring corresponding to seating and standing positions of said body support frame, respectively.2. A wheelchair as defined in claim 1, wherein said locking means comprises a valve operation lever carried by said gas spring receiver for operating a valve of said gas spring, an operation lever mounted on one of said pair of elbow supports, and an operation wire operably connecting said valve operation lever and said operation lever, whereby gripping of said operation lever operates said valve thereby permitting extension and retraction of said gas spring whereas releasing said operation lever causes locking of said gas spring so as to prevent the extension or retraction thereof.3. The wheelchair as defined in claim 1, wherein said waist support member and said back rest member, and said waist support member and said lower limb support member are connected to said main frame by link mechanisms, respectively.4. The wheelchair as defined in claim 3, wherein said link mechanism for said waist support member and said back rest member consists of a parallelogrammic 4-rod link mechanism.5. The wheelchair as defined in claim 3, wherein said link mechanism for said waist support member and said lower limb support member consists of a 4-rod link mechanism having an arbitrary length.輔助站立輪椅 （文獻(xiàn)翻譯) 1111Description:BACKGROUNDThis invention relates to a wheelchair which makes it possible for the handicapped with an extremely limited or no lower-limb function such as a paraplegic to change his or her posture from a seated posture to a stand-up posture and vice versa, using his or her push-up force (the body lift-up action of the handicapped by his or her upper limb) which he or she daily exercises, as the motive force, without using any external power.The wheelchair is a kind of vehicle which is required to cover a range of motion substantially the same as walking and can be regarded as a short-distance transportation vehicle. Accordingly, the wheelchair must have a full function as a daily instrument, a moving function and a function which makes it possible for the handicapped to carry out work by use of the wheelchair. However, in accordance with the conventional wheelchair, the user of the wheelchair can do the work only in the seated posture but cannot do work which can be done only in a stand-up posture because his or her hands cannot reach a high position.Wheelchairs using an external power source (such as motor drive using a battery as the power source) for a stand-up mechanism have been proposed in recent years for a wheelchair which enables the user to do a work in a stand-up posture. However, the wheelchairs of this kind involve the drawbacks that the charging work and maintenance are complicated, that the weight of the wheelchair increases and that the wheelchair itself is extremely expensive with limited versatility.輔助站立輪椅 （文獻(xiàn)翻譯) 1212DRAWINGSFIG. 1 is a side view showing the wheelchair in accordance with one embodiment of the present invention;輔助站立輪椅 （文獻(xiàn)翻譯) 1313FIG. 2 is a rear view of FIG. 1;輔助站立輪椅 （文獻(xiàn)翻譯) 1414FIG. 3 is a perspective view showing the state in which a gas spring as an extension member is used; FIG. 4 is a diagram showing the relation between the seat angle (stand-up angle) and the load applied to the seat and to the foot plate.輔助站立輪椅 （文獻(xiàn)翻譯) 1515PREFERRED EMBODIMENTIn FIGS. 1 and 2, the reference numeral 1 represents a main frame which supports driving wheels 2 and auxiliary wheels 3. An elbow support 4 is fixed to the upper part of the main frame 1 on each side. Reference numeral 5 represents a body support frame which consists of a lower limb support member 6, a waist support member 7 and a back rest member 8. These members are connected in such a manner that the adjacent members are turnable relative to each other. A foot plate 9 and a landing member 10 are fixed to the lower end of the lower limb support member 6. The tip of the waist support member 7 is bent in an arcuate form and a bracket 11 is fixed to the arcuate portion and is turnably fitted to the forward portion of the main frame 1 by a pivot 12. The stand-up mechanism of the body support frame 5 consists of the back rest member 8, the waist support member 7 and the lower limb support member 6 which are connected to one another by two 4-rod links. Among these links, the link for the back rest member 8 and the waist support member 7 is a parallelogrammic 4-rod link connecting the links a and b to the pivot 12, and the link for the waist support member 7 and the lower limb support member 6 is a 4-rod link which connects the joint between the both members 6, 7 and the link c to the pivot 12 and may have an arbitrary or optional length. These two link mechanisms are fitted to the main frame 1.A gas spring 13 as an extension member is interposed between the main frame 1 and the waist support member 7 so that the retracting motion of the spring 13 supports and can raise up and down the waist support member 7 with the pivot 12 as the support point. This gas spring is a kind of spring which utilizes the pressure of a high pressure gas sealed in a cylinder 14 as shown in FIG. 3 so that a piston and a rod 15 connected to the piston inside the cylinder are actuated and are stopped at an arbitrary position. A gas spring receiver 16 is fitted to the main frame 1 while the rod 15 is fitted to the waist support member 7. A valve operation button 17 (hereinafter referred to as a “l(fā)ock button“) can be operated by remote-controlling an operation lever 18 which is fitted to the elbow support member 4. In the drawings, the reference numeral 19 represents an operation wire, and 20, a valve operation lever.When the operation lever 18 is gripped, the valve operation lever 20 and the valve operation button 17 are actuated in the direction indicated by an arrow and release the lock of the gas spring 13. When the grip of the operation lever 18 is released, on the other hand, the valve operation lever 20 and the valve operation button 17 are actuated in the reverse direction whereby the gas spring 13 is locked.輔助站立輪椅 （文獻(xiàn)翻譯) 1616The motive force of the stand-up of the wheelchair in this embodiment relies upon the push-up force of the user of the wheelchair (the force of pushing up the body by the user's upper limbs) and the reaction of the gas spring. The user can take the stand-up posture by use of these two kinds of force. The mode of use is as follows.To stand up, the wheelchair may first be braked, and the knees and waist of user's body may then be fixed firmly to the wheelchair by a belt. After this preparation is completed, the operation lever 18 fitted to the elbow support 4 may be gripped and the lock button 17 of the gas spring is depressed so as to release the lock of the gas spring. In the stage where the lock is released, the gas spring starts operating. In this instance, the user puts his or her hand upon the elbow support 4 and then pushes up to reduce his or her weight acting upon the seat so that the rod 15 of the gas spring extends due to the gas reaction and the seat of the wheelchair starts elevating. During stand-up, the user releases the grip of the operation lever 18 at a desired height so as to eliminate the push force of the lock button 17 and to lock the gas spring. The seat can thus be fixed at that position.To return to the seated posture from the stand-up posture, first the lock of the gas spring may be released by the operation lever 18 and the user may then lower his or her body while gripping the elbow support 4 so as to apply his or her weight to the seat. In this instance, the weight of the user overcomes the gas reaction and the rod of the gas spring contracts so that the seat starts lowering slowly. In this case, too, the user can fix the seat at a desired position by locking the gas spring.In the embodiment described above, the maximum angle of stand-up of the waist support member is 75 degrees relative to the horizontal but the angle can be easily set to any value desired by the user. The angle of the back rest member 8 during stand-up can be always kept constant with respect to the horizontal by the parallelogrammic 4-rod link for the back rest member 8 and waist support member 7. The portion of the lower limb support member 6 can extend gradually with respect to the waist support member 7 so that it can correspond to the extension of the portion of the user below his or her knees with the extension of his or her knee joint during stand-up. This extension is attained because the link for the waist support member 7 and the lower limb support member 6 is constructed by the 4-rod link having an arbitrary length. In the embodiment described above, the quantity of extension is 50 mm with respect to the maximum stand-up but the value can be properly adjusted in accordance with the user's desire. Push-up during stand-up is necessary until the waist support member 7 becomes 30° relative to the horizontal but when it exceeds 30°, stand-up can be accomplished only by the force of the gas spring. Various other adjustments can be made in accordance with the weight of the user by appropriately adjusting the reaction of the gas spring and moreover, the gas spring can be replaced easily.輔助站立輪椅 （文獻(xiàn)翻譯) 11FIG. 4 is a diagram showing the relation between the seat angle (the stand-up angle of the waist support member 7) and the load A applied to the seat and between the seat angle and the load B applied to the foot plate 9. The abscissa represents the seat angle (degrees) and the ordinate the load (kgf). As is obvious from the diagram, the weight of the user is primarily borne by the seat when the angle is small and is borne by the foot plate and the seat when the angle is great. Accordingly, the user can keep the seated posture or the stand-up posture without the need of exerting an excessive force. Moreover, since a part of the weight is borne by the seat even at the time of the maximum stand-up, the user can rest against the back and smoothly carry out work in the stand-up posture.Although the foot plate 9 and the landing member 10 are fixed to the lower end of the lower limb support member 6 in the foregoing embodiment, the user can move the wheelchair while keeping the stand-up posture if small wheels are further fitted. The driving wheel may also be of an electric type with its operation switch being fitted to the elbow support member for easy operation of the wheelchair. Although the wheelchair of the foregoing embodiment is not foldable, it can be changed to a foldable type by incorporating a folding mechanism.In accordance with the present invention, the body support frame consists of the lower limb support member, the waist support member and the back rest member 8 and is actuated by the ingenious combination of the extension member with the link mechanisms. Accordingly, the user of the wheelchair can easily change from a seated position to a stand-up position and vice versa. Even when the user assumes a stand-up posture, he or she can support his or her body by the body support frame so that he or she can smoothly carry out a work in the stand-up posture. Since the user can take and keep the stand-up posture, decubitus and contracture of the joints of the handicapped with a minimal or no lower-limb function can be prevented. The use of the gas spring as the extension member makes it possible to continuously and smoothly change the body support frame from the seated posture to the stand-up posture and vice versa. The seat can be set and fixed at a desired position even during the shift of the posture without any difficulty to the user. Moreover, since the shift from the seated posture to the stand-up posture and vice versa can all be effected manually, the wheelchair of the present invention is easy to operate and can eliminate otherwise likely dangers to the user and complicated maintenance procedures.