Hand cart lock device

Abstract

To provide a handcart lock device that can extremely easily perform a release operation of a lock portion when releasing braking of a brake lever.SOLUTION: A brake lever 18 is provided at a spaced position spaced below a handle portion 11 of a handcart 1A, and is operated toward an upper braking position close to the handle portion 11 when braking right and left rear wheels 15R. A lock portion 41 biased by a coil spring 42 is rotatably provided at the center of the handle portion 11 in a right-left direction, and a hook portion 45 configured to lock the brake lever 18 at the braking position is provided. When the brake lever 18 is operated further upward from the braking position to the closest position, the lock at the braking position by the hook portion 45 is released, and the lock portion 41 is automatically moved from the locked position to the unlocked position by the biasing force of the coil spring 42, and the brake lever 18 is returned to the spaced position.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a locking device for a pushcart such as a silver cart. [Background technology]

[0002] Generally, a pushcart comprises left and right steering frames extending downward from a steering section that is held by the user with both hands, and left and right leg frames connected to the lower ends of the steering frames and supporting the front and rear wheels so that they can roll freely.

[0003] Some pushcarts are also equipped with a brake lever located at a distance from the steering unit, and by operating this brake lever toward a braking position closer to the steering unit, the left and right rear wheels of the front and rear wheels are braked (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-11045 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the conventional pushcart, when the brakes are applied, a locking mechanism is required to lock the brake lever in the braking position. Such a locking mechanism has a locking part on the steering part that detachably locks the brake lever in the braking position, and by locking the brake lever that has been operated to the braking position, the left and right rear wheels are kept in the braked state.

[0006] In this case, when releasing the brake lever, it is necessary to perform an operation to release the locking portion each time from the locking position where the locking portion is locked at the brake position of the brake lever to the unlocking position where the brake lever is released, which makes the operation to release the locking portion very cumbersome.

[0007] The present invention was made in consideration of the above points, and its purpose is to provide a locking device for a pushcart that allows the locking part to be released very easily when releasing the brake lever. [Means for solving the problem]

[0008] To achieve the above object, the present invention is based on a pushcart having left and right steering frames extending downward from a steering unit that is held by a user with both hands, and left and right leg frames connected to the lower ends of the steering frames and supporting front and rear wheels so that they can roll freely. Furthermore, a brake lever is provided at a distance from the steering unit, which is operated toward a braking position approaching the steering unit so as to brake the left and right rear wheels, and a locking mechanism is provided at the steering unit for locking the brake lever in the braking position so that the left and right rear wheels cannot roll. The brake lever is also set to be operable from the braking position to a closest position, which is even closer to the steering unit. On the other hand, the locking mechanism is provided with a locking portion that releasably locks the brake lever at the braking position, and a biasing means that biases the locking portion from a locking position where the brake lever is locked at the braking position toward an unlocked position where the brake lever is released. When the brake lever is operated from the braking position to the closest position, the locking portion at the braking position is released, and the locking portion is moved from the locking position to the unlocked position by the biasing force of the biasing means, thereby returning the brake lever to the separated position.

[0009] The brake lever may be supported below the steering unit so as to be slidable in the vertical direction along each steering frame, and may be operated from a separated position where it is separated downward from the steering unit to a braking position where it approaches the steering unit from below, and from this braking position to a closest position where it approaches the steering unit from below. The locking portion may be supported so as to be rotatable about the axis of the steering unit, and may have a hook portion that locks the brake lever in a state of abutting against the brake lever from below so that movement of the brake lever to the separated position from the braking position is restricted, and when the brake lever is operated from the braking position to the closest position, the locking by the hook portion at the locking position with respect to the brake lever is released, and the locking portion moves to the unlocked position by the biasing force of the biasing means.

[0010] In contrast to this, the brake lever may be supported rotatably about a horizontal axis extending in the left-right direction at a vertical midpoint of each steering frame, and may be operated from a separated position away from the steering unit forward to a braking position approaching the steering unit from the front, and from this braking position to a closest position approaching the steering unit further forward.The locking portion may be supported rotatably about the axis of the steering unit and have a hook that locks the brake lever in a state of abutting against the brake lever from the front so that movement of the brake lever to the separated position forward at the braking position is restricted, and when the brake lever is operated from the braking position to the closest position, the locking by the hook portion at the locking position with respect to the brake lever is released, and the locking portion moves to the unlocked position by the biasing force of the biasing means.

[0011] Furthermore, the biasing means may be a coil spring wound around a portion of the steering section, one end of which is fixed to the steering section and the other end of which is fixed to the locking section, and the coil spring may be configured to extend when the brake lever is locked by the hook section at the braking position, and to contract when the locking by the hook section at the braking position is released, thereby applying a biasing force to the locking section.

[0012] A slider that moves linearly up and down between the separated position and the closest position of the brake lever is connected to the brake lever, and a sliding body that slides up and down within the slider is provided. Furthermore, brake pads that press against the left and right rear wheels when the brake lever is in the braking position are connected to the sliding body via a wire, so that the slider also approaches the steering unit when the brake lever is operated toward the braking position, and also moves away from the steering unit when the brake lever is in the separated position. The wire may be connected to a lower end of the sliding body, and the sliding body may be configured to abut against a bottom of the slider via an elastic body that can expand and contract when the brake lever is operated toward the braking position. [Effects of the Invention]

[0013] In summary, when releasing the brake lever, if the brake lever, which is locked by the locking portion at the braking position close to the steering unit, is operated to the closest position closer to the steering unit, the locking portion at the braking position is released, and the locking portion automatically moves from the locked position to the unlocked position due to the biasing force of the biasing means. Therefore, when releasing the brake lever, there is no need to perform a release operation to move the locking portion from the locked position, which locks the brake lever at the braking position, to the unlocked position, where the brake lever is released. As a result, when releasing the brake lever, it is only necessary to operate the brake lever to the closest position, and the locking portion can be automatically moved from the locked position to the unlocked position simply by operating the brake lever to the closest position.

[0014] Furthermore, when releasing the brake lever, if the brake lever, which is locked in a braking position approaching the steering unit while being abutted from below by a hook-shaped locking portion, is operated further upward to the closest position relative to the steering unit, the locking of the brake lever by the hook portion from below so as to restrict movement of the brake lever from the braking position to the downward separated position is released, and the locking portion, which has been restricted in movement at the locked position by the engagement of the hook portion with the brake lever, automatically moves to the unlocked position by the biasing force of the biasing means. As a result, when releasing the brake lever, simply operating the brake lever further upward to the closest position can automatically move the locking portion from the locked position to the unlocked position.

[0015] In contrast, when releasing the brake lever, if the brake lever, which has been locked in a state in which the hook portion abuts from the front at the braking position approaching the steering unit, is operated to the closest position approaching the steering unit from further forward, the locking by the hook portion of the brake lever, which has restricted movement from the braking position to the forward separated position, is released, and the locking portion automatically moves to the unlocked position by the biasing force of the biasing means. As a result, when releasing the brake lever, simply operating the brake lever further rearward to the closest position makes it possible to automatically move the locking portion from the locked position to the unlocked position.

[0016] Furthermore, a coil spring is used as the biasing means, wound around a portion of the steering section, with one end of this coil spring fixed to the steering section and the other end fixed to the locking section, and the coil spring is extended at the locking position of the locking section that locks the brake lever in the braking position, and when the locking at the braking position by the locking section is released, the coil spring is contracted to apply a biasing force to the locking section. As a result, when the brake lever is further operated to the closest position to release the brake lever, the biasing force of the coil spring can smoothly move the locking section from the locking position to the unlocked position.

[0017] In addition, the brake pads are connected via wires to a sliding body that can slide within a slider that moves toward or away from the steering unit in conjunction with the operation of the brake lever, and when the brake lever is operated toward the braking position, the sliding body abuts against the bottom of the slider via an elastic body that can expand and contract. Therefore, if the brake lever is accidentally and suddenly operated to the braking position, the sliding body elastically abuts against the bottom of the slider via the elastic body, and the pressure of the brake pads on the left and right rear wheels is alleviated. This makes it possible to prevent sudden braking due to erroneous operation of the brake lever to the braking position. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view of a pushcart equipped with a locking device according to a first embodiment of the present invention, with the brake lever in a separated position, as viewed obliquely from the front right side. [Figure 2] FIG. 2 is a front view of the pushcart of FIG. 1 as seen from the front. [Figure 3] 2 is a right side view of the pushcart of FIG. 1 as seen from the right side. [Figure 4] FIG. 2 is a rear view of the pushcart of FIG. 1 as seen from behind. [Figure 5] FIG. 2 is a perspective view of the pushcart of FIG. 1 as seen obliquely from the front left side. [Figure 6] FIG. 6 is a plan view of the pushcart of FIG. 5 as seen from above. [Figure 7] 1 with the brake lever in the braking position, as viewed from the diagonally front right side. [Figure 8] FIG. 8 is a front view of the pushcart of FIG. 7 as seen from the front. [Figure 9] FIG. 8 is a right side view of the pushcart of FIG. 7 as seen from the right side. [Figure 10] FIG. 10 is a perspective view of the pushcart of FIG. 9 as seen obliquely from the front left side. [Figure 11] FIG. 11 is a plan view of the pushcart of FIG. 10 as seen from above. [Figure 12] FIG. 7 is a cross-sectional view taken along line AA in FIG. 6. [Figure 13] FIG. 12 is a cross-sectional view taken along line BB in FIG. [Figure 14] FIG. 3 is a cross-sectional view taken along line CC in FIG. 2. [Figure 15] FIG. 9 is a cross-sectional view taken along line DD in FIG. 8. [Figure 16] FIG. 10 is a perspective view of a pushcart equipped with a locking device according to a second embodiment of the present invention, viewed obliquely from the front right side with the brake lever in the separated position. [Figure 17] FIG. 17 is a front view of the pushcart of FIG. 16 as seen from the front. [Figure 18] 17 is a right side view of the pushcart of FIG. 16 as seen from the right side. [Figure 19] FIG. 17 is a rear view of the pushcart of FIG. 16 as seen from behind. [Figure 20] 17 is a perspective view of the pushcart of FIG. 16 with the brake lever in the braking position, as seen obliquely from the front right side. [Figure 21] FIG. 21 is a front view of the pushcart of FIG. 20 as seen from the front. [Figure 22] 21 is a right side view of the pushcart of FIG. 20 as seen from the right side. [Figure 23] FIG. 18 is a cross-sectional view taken along line EE in FIG. [Figure 24] FIG. 22 is a cross-sectional view taken along line FF in FIG. 21. [Figure 25] FIG. 18 is a cross-sectional view taken along line GG in FIG. [Figure 26] FIG. 22 is a cross-sectional view taken along line HH in FIG. 21. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, a pushcart according to an embodiment of the present invention will be described with reference to the drawings.

[0020] Fig. 1 shows a perspective view of a pushcart equipped with a locking device according to a first embodiment of the present invention, with the brake lever in the released position, as viewed diagonally from the front right. Fig. 2 shows a front view of the pushcart of Fig. 1, Fig. 3 shows a right side view of the pushcart of Fig. 1, as viewed from the right side, and Fig. 4 shows a rear view of the pushcart of Fig. 1, as viewed from the rear. Fig. 5 shows a perspective view of the pushcart of Fig. 1, as viewed diagonally from the front left, and Fig. 6 shows a plan view of the pushcart of Fig. 5, as viewed from above.

[0021] As shown in Figures 1 to 6, the pushcart 1A is used as a silver cart and is equipped with a handle 11 at its upper end as a steering mechanism. The handle 11 extends left and right so that it is easy for the user to grip. The pushcart 1A also has handle brackets 10, 10 extending downward from the left and right ends of the handle 11, and handle frames 12, 12 as steering frames extending downward from the left and right handle brackets 10, 10, respectively. Each handle bracket 10 consists of an upper portion 101 extending straight up and down, and a lower portion 102 bending inward from the upper portion 101 and extending straight downward.

[0022] The handle section 11 is composed of a cylindrical core material 111 and a cylindrical outer surface material 110 that covers the periphery of this core material 111. The left and right handle frames 12, 12 each include an upper handle frame portion 121, 121 attached to the lower part 102 of the handle bracket 10, and a lower handle frame portion 122 extending downward from the lower end of each upper handle frame portion 121. Each handle frame 12 is fixed in an optimal position with the upper end of each lower handle frame portion 122 inserted into the lower end of the upper handle frame portion 121 in a manner that allows the length to be adjusted.

[0023] The lower ends of the lower handle frame portions 122 are fixed in a state in which they are inserted into both left and right ends of a generally U-shaped frame 123 that opens upward. The upper ends of the left and right sides of this U-shaped frame 123 are firmly connected to each other by an upper horizontal frame 124 that extends in the left-right direction.

[0024] Leg support brackets 13, 13 are fixedly attached to the lower left and right sides of the U-shaped frame 123, i.e., approximately in the vertical center. The upper ends of front wheel leg frames 14, 14 are rotatably supported by horizontal pins 141 at the lower front end positions of the left and right leg support brackets 13, 13. The left and right leg support brackets 13, 13 are firmly connected by a lower horizontal frame 125 that extends laterally between approximately the middle portions of the left and right sides of the U-shaped frame 123.

[0025] Each front wheel leg frame 14 has an upper straight section 142 that extends substantially horizontally forward from the lower front end of each leg support bracket 13, and a lower straight section 143 that extends diagonally downward and forward from the front end of this upper straight section 142. A front wheel 14F is supported for free roll at the lower end of each lower straight section 143. The lower ends of the front wheel leg frames 14 are firmly connected to each other by front horizontal frames 144 that extend in the left-right direction.

[0026] The upper ends of rear wheel leg frames 15, 15 are rotatably supported by horizontal pins 151 at the lower rear ends of the left and right leg support brackets 13, 13. Each rear wheel leg frame 15 is formed in a straight line extending diagonally downward and rearward from the lower rear end of the leg support bracket 13, and a rear wheel 15R is supported at its lower end so that it can roll freely. The lower ends of the rear wheel leg frames 15 are firmly connected to each other by rear horizontal frames 152 extending in the left-right direction.

[0027] Brake pads 16 for braking the respective rear wheels 15R are rotatably supported at the lower end of each rear wheel leg frame 15. A brake lever 18 (braking lever) extending in the left-right direction is provided below the handlebars 11. Both left and right ends of this brake lever 18 are supported by the respective handlebar brackets 10, and it is operable to slide up and down along the respective handlebar frames 12 below the handlebars 11. When the brake lever 18 is in a separated position away from the handlebars 11 and downward, the brake pads 16 are prevented from pressing against the respective rear wheels 15R, and the vehicle is maintained in a state in which it can travel.

[0028] A seat 17 on which a user can sit is provided between the upper straight sections 142 of each front wheel leg frame 14. The seat 17 has a roughly U-shaped seat frame 171 that opens to the rear. This seat frame 171 is rotatably supported via horizontal shafts 172 at the upper front end positions of each leg support bracket 13. The seat frame 171 abuts against the upper straight sections 142 of each front wheel leg frame 14 and is held in a horizontal position that allows a user to sit on it.

[0029] Furthermore, a pair of left and right folding links 3, 3 for folding each front wheel leg frame 14 and each rear wheel leg frame 15 is provided between the middle of the lower straight section 143 of each front wheel leg frame 14 and the middle of each rear wheel leg frame 15 on both the left and right sides of the U-shaped frame 123. Each folding link 3 includes a front link 31 whose front end is rotatably supported on the middle of the lower straight section 143 of the front wheel leg frame 14 and extends rearward, and a rear link 32 whose rear end is rotatably supported on the middle of the rear wheel leg frame 15 and extends forward.

[0030] The rear end of each front link 31 and the front end of each rear link 32 are rotatably supported via a horizontal shaft 33 extending in the left-right direction. This horizontal shaft 33 is supported at the lower ends of extension links 34 extending downward from both the left and right ends of the U-shaped frame 123. Each front link 31 and each rear link 32 can be converted between a traveling state around the horizontal shaft 33 and a folded state via the extension links 34 on both the left and right sides of the U-shaped frame 123.

[0031] Fig. 7 shows a perspective view of the pushcart 1A of Fig. 1 when the brake lever is in the braking position, as viewed diagonally from the front right. Fig. 8 shows a front view of the pushcart 1A of Fig. 7 when viewed from the front, and Fig. 9 shows a right side view of the pushcart 1A of Fig. 7 when viewed from the right side. Fig. 10 shows a perspective view of the pushcart 1A of Fig. 9 when viewed diagonally from the front left, and Fig. 11 shows a plan view of the pushcart 1A of Fig. 10 when viewed from above.

[0032] As shown in FIGS. 7 to 11, when the brake lever 18 is pulled up from a separated position (the position shown in FIGS. 1 to 6) allowing the vehicle to travel toward the handlebars 11 (upward), it moves to a braking position (the position shown in FIGS. 7 to 11) where it approaches the handlebars 11 from below. When the brake lever 18 is pulled up to the braking position, the brake pads 16 are pressed against the rear wheels 15R via brake operation wires W (wires), thereby braking the rear wheels 15R. Each brake operation wire W is inserted into a tube WT that slidably covers the outside of the wires. In this case, the front ends of the brake pads 16 are connected to each other via a brake rod 19 extending in the left-right direction, and the lower ends of the brake operation wires W are connected to both left and right ends of the brake rod 19.

[0033] Fig. 12 is a cross-sectional view taken along line AA in Fig. 6, and Fig. 13 is a cross-sectional view taken along line BB in Fig. 11. As shown in Figs. 12 and 13, the upper part 101 of each handle bracket 10 is provided with rectangular chambers 21 that extend linearly in the vertical direction at both left and right ends of the brake lever 18 within the operable range of the brake lever 18. Each chamber 21 is provided with a rectangular slider 22 that slides vertically within the chamber 21. The inner surfaces of the upper parts 101 of each handle bracket 10 are open in directions facing each other (towards the brake lever 18). The left and right ends of the brake lever 18 are connected to the outer peripheral walls of each slider 22 via openings in the inner surfaces of the upper parts 101 of each handle bracket 10, and the sliders 22 move vertically within each chamber 21 as the brake lever 18 is operated vertically.

[0034] A sliding body 23, the upper end of which is connected to the underside of the brake operating wire W, is housed in each slider 22 and is slidable up and down inside the slider 22. A compression spring 24 serving as an elastic body is compressed between the bottom of the slider 22 and the underside of the sliding body 23. When the brake lever 18 is operated toward the braking position, the sliding body 23 elastically abuts against the bottom of the slider 22 via the compression spring 24, and the brake lever 18 and the brake operating wire W are elastically connected via the compression spring 24.

[0035] Fig. 14 is a cross-sectional view taken along line CC in Fig. 2, and Fig. 15 is a cross-sectional view taken along line DD in Fig. 8. As shown in Fig. 14 and Fig. 15, a locking mechanism 4 is provided in the center of the handle portion 11 in the left-right direction, which locks the brake lever 18 in a braking position so that the left and right rear wheels 15R, 15R cannot roll when the brake pads 16 come into contact with them.

[0036] The locking mechanism 4 is housed in an annular groove 40 formed by cutting the outer cover 110 circumferentially down to the core material 111 in the left-right central portion of the handle portion 11. The locking mechanism 4 is rotatably supported about the axis of the core material 111 of the handle portion 11 and includes a locking portion 41 that releasably locks the brake lever 18 in the braking position, and a coil spring 42 as biasing means that biases the locking portion 41 from a locking position (position shown in FIG. 15) that locks the brake lever 18 in the braking position toward a release position (position shown in FIG. 14) where the brake lever 18 is released from braking. In this case, the width of the groove 40 in the left-right central portion of the handle portion 11 is approximately the same as the width of the locking portion 41.

[0037] The locking portion 41 has a notched groove 43 cut out within a range of about 40° in the circumferential direction, and a fixing pin member 44 fixed to the core material 111 of the handle portion 11 via this notched groove 43 allows rotation around the axis within the circumferential range of the notched groove 43. In addition, the locking portion 41 has a hook portion 45 protruding radially outward. The hook portion 45 locks the brake lever 18 from below and abuts against the central portion of the brake lever 18 so as to restrict movement of the brake lever 18 from the braking position to the separated position. The hook portion 45 is converted by rotation of the locking portion 41 between an locking position (position shown in FIG. 15) where the hook portion 45 locks the brake lever 18 from below within the notched groove 43, and an unlocking position (position shown in FIG. 14) where the hook portion 45 is released from the locking position from below.

[0038] The coil spring 42 is wound approximately halfway around the locking portion 41, with one end fixed to the fixing pin member 44 (handle portion 11) and the other end fixed to the base of the hook portion 45. This coil spring 42 expands when the brake lever 18 is locked by the hook portion 45 in the braking position, and contracts when the locking at the braking position by the hook portion 45 is released, and the biasing force generated by the contraction biases the hook portion 45 (locking portion 41) toward the unlocking position. In this case, when the hook portion 45 is in the locked position, the locking portion 41 abuts against the center of the brake lever 18 from below so as to embrace it, so that the locking portion 41 is held in the locked position against the biasing force of the coil spring 42.

[0039] The slider 22 of each handle bracket 10 is housed in the chamber 21 with a gap S (see FIG. 13) at the top when the brake lever 18 is locked in the braking position. In other words, the brake lever 18 can slide upward on the slider 22 by the amount of the gap S at the top in the chamber 21, and is thus set to be operated from a braking position where each rear wheel 15R is braked to a closest position where the brake lever 18 approaches the handle portion 11 further upward.

[0040] In short, when the brake lever 18 is operated from the locked state in the braking position to the closest position, a vertical space is created between the brake lever 18 in the braking position and the hook portion 45 that was holding it from below in the engaging position, and as a result, the engaging portion 41 automatically moves from the engaging position to the unlocked position by the force of the coil spring 42, and the brake lever 18 is returned to the separated position.

[0041] Therefore, in this embodiment, when releasing the brake lever 18, the brake lever 18, which is engaged by the hook portion 45 of the engaging portion 41 at the braking position where it approaches the handle portion 11 from below, is moved upward to the closest position where it approaches the handle portion 11 even closer, thereby creating a vertical space between the hook portion 45 and the brake lever 18, and the engaging portion 41 automatically moves from the engaged position to the disengaged position by the biasing force of the coil spring 42, returning the brake lever 18 to the separated position. Therefore, when releasing the brake lever 18 at the braking position, there is no need to perform a release operation to move the engaging portion 41 from the engaged position where it engages the brake lever 18 at the braking position to the disengaged position where the brake lever 18 is released. As a result, when releasing the brake lever 18, it is only necessary to operate the brake lever 18 to the closest position, and the engaging portion 41 can be automatically moved from the engaged position to the disengaged position simply by operating the brake lever 18 to the closest position.

[0042] Furthermore, the coil spring 42 is wound approximately halfway around the locking portion 41, with one end fixed to the fixing pin member 44 and the other end fixed to the base of the hook portion 45, and is configured to extend when the locking portion 41 is in the locking position where it locks the brake lever 18 in the braking position, and contract when the locking at the braking position by the locking portion 41 is released, thereby applying a biasing force to the locking portion 41. As a result, when the brake lever 18 is operated to the closest position to release the brake, the biasing force of the coil spring 42 can smoothly move the locking portion 41 to the unlocked position.

[0043] Furthermore, the brake pads 16 are connected via a brake operation wire W to a sliding body 23 that is slidable within a slider 22 that moves toward or away from the handle portion 11 in conjunction with the operation of the brake lever 18, and when the brake lever 18 is operated toward the braking position, the sliding body 23 is brought into contact with the bottom of the slider 22 via an expandable compression spring 24. Therefore, when the brake lever 18 is erroneously and suddenly operated toward the braking position, the sliding body 23 elastically contacts the bottom of the slider 22 via the compression spring 24, thereby reducing the pressure of the brake pads 16 against the left and right rear wheels 15R, 15R. This makes it possible to prevent sudden braking due to erroneous operation of the brake lever 18 to the braking position.

[0044] Next, a second embodiment of the present invention will be described with reference to the drawings.

[0045] Fig. 16 is a perspective view of a pushcart equipped with a locking device according to a second embodiment of the present invention, with the brake lever in the released position, as viewed diagonally from the front right. Fig. 17 is a front view of the pushcart of Fig. 16, Fig. 18 is a right side view of the pushcart of Fig. 16, as viewed from the right side, and Fig. 19 is a rear view of the pushcart of Fig. 16, as viewed from the rear.

[0046] As shown in Figures 16 to 19, pushcart 1B is used as a silver cart and is provided with a handle portion 51 at the top end as a steering mechanism. Handle portion 51 is provided with a handle bar 511 that extends straight in the left-right direction so that it is easy for the user to grip, and support pieces 512, 512 that protrude downward from both the left and right ends of handle bar 511. Handle bar 511 is made up of a cylindrical core material 510 and a cylindrical outer surface material 513 that covers the periphery of core material 510.

[0047] The handcart 1B also includes a handle frame 52 as a steering frame, the upper end of which is connected to the lower end of each support piece 512 of the handle portion 51 via a handle bracket 50. Each handle frame 52 extends straight downward from the handle bracket 50.

[0048] The upper ends of a pair of left and right front wheel leg frames 53, 53 (leg frames) extending vertically relative to the lower end of each handle frame 52 are inserted in an adjustable length manner and fixed in an optimum position. Each front wheel leg frame 53 has an upper straight section 531 extending straight in the vertical direction from the lower end of the handle frame 52, and a lower straight section 533 extending diagonally downward and forward from the lower end of the upper straight section 531 with a bent section 532 in between.

[0049] A front wheel 14F is supported for free rolling at the lower end of the lower straight portion 533 of each front wheel leg frame 53. The lower ends of the lower straight portions 533 are firmly connected to each other by a horizontal frame 530 extending in the left-right direction.

[0050] A leg bracket 534 is fixed to the lower end of the upper straight portion 531 of each front wheel leg frame 53, and the upper ends of a pair of left and right rear wheel leg frames 55, 55 (leg frames) extending diagonally downward and rearward are supported by this leg bracket 534 so as to be rotatable about horizontal shafts 551. A rear wheel 15R is supported at the lower end of each rear wheel leg frame 55 so as to be rollable. The lower ends of the rear wheel leg frames 55 are firmly connected to each other by horizontal frames 552 extending in the left-right direction.

[0051] Brake pads 16 for braking the respective rear wheels 15R are rotatably supported on the lower end of each rear wheel leg frame 55. Brake levers 59 extending in the left-right direction are rotatably supported on the front side of the handlebar 511 of the handle unit 51 around horizontal axes on both left and right ends. When the brake lever 59 is rotated so as to be pulled toward the handle unit 51 (toward the user), each brake pad 16 is actuated via the brake operating wire W to brake the rear wheel 15R.

[0052] A seating surface 56 on which a user can sit is provided between the lower ends of the upper straight portions 531 of the front wheel leg frames 53. The seating surface 56 includes a seat frame 57 that is roughly U-shaped and opens rearward.

[0053] The seat frame 57 includes a pair of left and right side frame pieces 572, 572 that are rotatably supported at positions rearward of the center in the fore-and-aft direction via horizontal shafts 571 on the leg brackets 534 at the lower ends of the upper straight sections 531 of the front wheel leg frames 53, and a front connecting frame piece 573 that connects the tips (front ends) of the side frame pieces 572. The base ends (rear ends) of the left and right side frame pieces 572, 572 of the seat frame 57 are connected by a rear connecting frame piece 574 that extends in the left-right direction.

[0054] Furthermore, a pair of left and right folding links 6, 6 for folding each rear wheel leg frame 55 relative to each front wheel leg frame 53 is provided between the lower end of the lower straight section 533 of each front wheel leg frame 53 and the lower end of each rear wheel leg frame 55. Each folding link 6 includes a front link 61 whose front end is rotatably supported on the lower end of the lower straight section 533 of the front wheel leg frame 53 and extends rearward, and a rear link 62 whose rear end is rotatably supported on the lower end of the rear wheel leg frame 55 and extends forward.

[0055] The front link 61 and the rear link 62 are rotatably supported via a horizontal shaft 63 extending in the left-right direction, and the front end of the rear link 62 abuts against a protrusion 611 that protrudes approximately horizontally from the rear end of the front link 61, thereby maintaining each rear wheel leg frame 55 in a state in which it can travel relative to each front wheel leg frame 53. In addition, a biasing spring 64 is stretched between the protrusion protruding from the rear end of the front link 61 and a position closer to the front than the center of the rear link 62, and the biasing force of this biasing spring 64 maintains each rear wheel leg frame 55 in a state in which it can travel relative to each front wheel leg frame 53 and in a folded state.

[0056] A pair of left and right vertical links 65, 65 extending in the up-down direction are rotatably connected between an intermediate position of each front link 61 and the front side of each side frame piece 572 of the seat frame 57 via upper and lower horizontal shafts 651, 652. When the seat frame 57 is rotated around the horizontal shaft 571, each vertical link 65 bends and stretches the front link 61 and the rear link 62 in conjunction with this rotation, thereby converting each rear wheel leg frame 55 relative to each front wheel leg frame 53 between a state ready for travel and a folded state.

[0057] Fig. 20 shows a perspective view of the pushcart of Fig. 16 when the brake lever is in the braking position, as seen diagonally from the front right. Fig. 21 shows a front view of the pushcart of Fig. 20 when seen from the front, and Fig. 22 shows a right side view of the pushcart of Fig. 20 when seen from the right side.

[0058] As shown in Figures 20 to 22, the brake lever 59 is formed in a generally U-shape that opens downward, and is rotatably supported on the handle bracket 50 at the upper end of each handle frame 52. When the brake lever 59 is pulled toward the handle unit 11 (rearward) from a separated position (position shown in Figures 16 to 19) where the vehicle is capable of traveling, it rotates to a braking position (position shown in Figures 20 to 22) where it approaches the handle bar 511 of the handle unit 51 from the front. When the brake lever 59 is pulled to the braking position, each brake pad 16 operates to press against each rear wheel 15R via the brake operating wire W, thereby braking each rear wheel 15R.

[0059] Figure 23 is a cross-sectional view taken along line EE in Figure 17, and Figure 24 is a cross-sectional view taken along line FF in Figure 21. As shown in Figures 23 and 24, a protrusion 591 that protrudes rearward is integrally formed on each of the left and right ends of the brake lever 59. The tip (rear end) of each protrusion 591 is supported by each handle bracket 50 via a horizontal shaft 592 that extends in the left-right direction. Each handle bracket 50 is provided with a protrusion 501 that protrudes forward.

[0060] The upper surface of the protruding piece 501 of each handle bracket 50 and the front lower surface of each protruding piece 591 of the brake lever 59 are formed into flat surfaces that abut without any gap when the brake lever 59 is in a spaced position away from the handlebar 511 and forwardly spaced from the handlebar 511. In other words, the front lower surface of each protruding piece 591 of the brake lever 59 comes into contact with the upper surface of the protruding piece 501 of each handle bracket 50, and the brake lever 59 is held in the spaced position.

[0061] The protrusion 501 of each handle bracket 50 has an insertion hole 502 for fixing the upper end of the tube WT of the brake operation wire W, and the upper end of the brake operation wire W is led out through the insertion hole 502 to the front side of the lower surface of each protrusion 591 of the brake lever 59. The upper end of the brake operation wire W is attached to the front part of the lower surface of each protrusion 591 of the brake lever 59. When the brake lever 59 is braked by pulling it from a spaced position relative to the handlebar 511 to a braking position, the front part of the lower surface of each protrusion 591 of the brake lever 59 rotates about the horizontal axis 592 and moves away from the upper surface of the protrusion 501 of each handle bracket 50, and the brake operation wire W is pulled out from the tube WT, and the brake pads 16 brake each rear wheel 15R.

[0062] Fig. 25 is a cross-sectional view taken along line GG in Fig. 17, and Fig. 26 is a cross-sectional view taken along line HH in Fig. 21. As shown in Fig. 25 and Fig. 26, a locking mechanism 7 is provided in the center of the handlebar 511 of the handle section 51 in the left-right direction, which locks the brake lever 59 in the braking position so that the left and right rear wheels 15R, 15R cannot roll when the brake pads 16 come into contact with them.

[0063] The locking mechanism 7 is housed in an annular groove 70 formed by cutting the outer cover 513 circumferentially down to the core material 510 in the left-right central portion of the handlebar 511. The locking mechanism 7 is rotatably supported about the axis of the core material 510 of the handlebar 511, and is equipped with a locking portion 71 that releasably locks the brake lever 18 in the braking position, and a coil spring 72 as biasing means that biases the locking portion 71 from a locking position (position shown in Figures 24 and 26) where the locking portion 71 locks the brake lever 59 in the braking position, toward a release position (position shown in Figures 23 and 25) where the brake lever 59 is released from braking. In this case, the width of the groove 70 in the left-right central portion of the handlebar 511 is approximately the same as the width of the locking portion 71.

[0064] The locking portion 71 has a notched groove 73 cut out in the circumferential direction thereof, and a fixing pin member 74 is fixed to the reduced-diameter portion 510 of the handlebar 511 via this notched groove 73, allowing rotation around the axis within a predetermined range in the circumferential direction of the notched groove 73 (for example, within about 50°). The locking portion 71 also has a hook portion 75 protruding radially outward. The hook portion 75 engages with the center of the brake lever 59 from the front so as to embrace the brake lever 59 from the front, restricting movement of the brake lever 59 to the front-separated position when the brake lever 59 is in the braking position. The hook portion 75 can be moved within the predetermined range in the circumferential direction of the notched groove 73 between an engaged position (position shown in FIGS. 24 and 26 ) where the hook portion 75 engages the brake lever 59 from the front, and an unengaged position (position shown in FIGS. 23 and 25 ) where the hook portion 75 is unengaged from the brake lever 59 from the front.

[0065] The coil spring 72 is wound approximately halfway around the locking portion 71, with one end fixed to the fixing pin member 74 (handle portion 51) and the other end fixed to the base of the hook portion 75. This coil spring 72 expands when the brake lever 59 is locked by the hook portion 75 in the braking position, and contracts when the locking at the braking position by the hook portion 75 is released, and the biasing force generated by the contraction biases the hook portion 75 (locking portion 71) toward the unlocking position. In this case, when the hook portion 75 is in the locked position, the locking portion 71 abuts against the center of the brake lever 59 from the front so as to embrace it, so that the locking portion 71 is held in the locked position against the biasing force of the coil spring 72.

[0066] The brake lever 59 is set to be operated to a closest position where it approaches the handle portion 51 from the front when it is locked by the locking portion 71 at the braking position. In other words, when the brake lever 59 is operated from the locked state at the braking position to the closest position, a space is created in the front-to-rear direction between the brake lever 59 at the braking position and the hook portion 75 that has been holding the brake lever 59 from the front at the locking position, and the locking portion 71 automatically moves from the locking position to the unlocked position by the biasing force of the coil spring 72, returning the brake lever 59 to the separated position.

[0067] Therefore, in this embodiment, when releasing the brake lever 59, if the brake lever 59, which is locked in a state in which it is held from the front by the hook portion 75 at the braking position approaching the handlebar 511, is operated to the closest position approaching the handlebar 511 further forward, the brake lever 59 is released from contact with the hook portion 75 that had restricted movement of the brake lever 59 from the braking position to the forward separated position, and the locking portion 71, whose movement was restricted at the locked position by contact with the brake lever 59, automatically moves to the unlocked position by the biasing force of the coil spring 72. As a result, when releasing the brake lever 59, simply by operating the brake lever 59 further forward to the closest position, the locking portion 71 can be automatically moved from the locked position to the unlocked position.

[0068] The present invention is not limited to the above-described embodiments, and includes various other modifications. For example, in the above-described embodiments, the locking devices 4, 7 are provided as pushcarts 1A, 1B, which are applied to a silver cart. However, the present invention may also be applied to pushcarts such as strollers and carts.

[0069] Furthermore, in the above-described embodiments, the coil springs 42 and 72 are used as the biasing means for the locking mechanisms 4 and 7, but an elastic body such as rubber may also be used as the biasing means.

[0070] Furthermore, in the first embodiment, the compression spring 24 is mounted between the bottom of the slider 22 and the sliding body 23 in each chamber 21 at both the left and right ends of the brake lever 18, but an elastic body such as rubber may be mounted instead.

[0071] Furthermore, in each of the above-described embodiments, the locking mechanism 4, 7 is housed in an annular groove 40, 70 in the left-right center of the handle portion 11, 51, where the outer surface material 110, 513 is cut circumferentially down to the core material 111, 510, but the locking mechanism may also be attached directly to the handle portion made of a single tube. [Explanation of symbols]

[0072] 1A Wheelbarrow 1B Wheelbarrow 11 Handle section (steering section) 12 Handle frame (steering frame) 13 Front wheel leg frame (leg frame) 14F front wheel 15 Rear wheel leg frame (leg frame) 15R rear wheel 18 Brake lever (braking lever) 22 Slider 23 Sliding body 24 Compression spring (elastic body) 4 Locking mechanism 41 Locking part 42 Coil spring (biasing means) 45 Hook part 51 Handle section (steering section) 52 Handle frame (steering frame) 53 Front wheel leg frame (leg frame) 55 Rear wheel leg frame (leg frame) 59 Brake lever (braking lever) 7 Locking mechanism 71 Locking part 72 Coil spring (biasing means) 75 Hook part W Brake operation wire (wire)

Claims

1. A pushcart having left and right steering frames extending downward from a steering section that is held by a user with both hands, and left and right leg frames connected to the lower ends of the steering frames and supporting front and rear wheels so that the wheels can roll freely, A brake lever is provided at a separated position away from the steering unit, and is operated toward a braking position approaching the steering unit so as to brake the left and right rear wheels of the front and rear wheels; the steering unit is provided with a locking mechanism that locks the brake lever in the braking position so that the left and right rear wheels cannot roll, The brake lever is set to be operable from the braking position to a closest position closer to the steering unit, The locking mechanism is a locking portion that detachably locks the brake lever in a braking position; a biasing means for biasing the locking portion from a locking position where the locking portion is locked at the braking position of the brake lever toward a locking release position where the brake lever is released from braking; and When the brake lever is operated from the braking position to the closest position, the locking portion at the braking position is released, and the locking portion is moved from the locking position to the unlocked position by the biasing force of the biasing means, thereby returning the brake lever to the separated position.

2. the brake lever is supported below the steering unit so as to be slidable in the vertical direction along each of the steering frames, and is set to be operated from a separated position at which it is separated downward from the steering unit to a braking position at which it approaches the steering unit from below, and to be operated from this braking position to a closest position at which it approaches the steering unit from further below, 2. A locking device for a pushcart as set forth in claim 1, wherein the locking portion is supported so as to be rotatable about the axis of the steering portion, and has a hook portion that locks the brake lever in a state in which it abuts against the brake lever from below so that movement of the brake lever to the downward separated position is restricted when the brake lever is in the braking position, and when the brake lever is operated from the braking position to the closest position, the locking by the hook portion at the locking position with respect to the brake lever is released and the locking portion moves to the unlocked position by the biasing force of the biasing means.

3. The brake lever is supported rotatably around a horizontal axis extending in the left-right direction at a vertical midpoint of each steering frame, and is set to be operated from a distanced position away from the front of the steering unit to a braking position approaching the steering unit from the front, and also to be operated from the braking position to a closest position approaching the steering unit from the front, 2. A locking device for a pushcart as set forth in claim 1, wherein the locking portion is supported so as to be rotatable about the axis of the steering portion, and has a hook portion that locks the brake lever in a state of abutting against the brake lever from the front so that movement of the brake lever to the forward separated position is restricted when the brake lever is in the braking position, and when the brake lever is operated from the braking position to the closest position, the locking by the hook portion at the locking position with respect to the brake lever is released and the locking portion moves to the unlocked position by the biasing force of the biasing means.

4. As the biasing means, a coil spring is applied, one end of which is wound around a part of the periphery of the steering section and fixed to the steering section, and the other end of which is fixed to the locking section, 4. A pushcart locking device according to claim 2, wherein the coil spring is extended when the brake lever is locked by the hook portion in the braking position, and contracts when the locking by the hook portion in the braking position is released, thereby applying a biasing force to the locking portion.

5. A slider is connected to the brake lever, and the slider moves linearly in the up-down direction between the separated position and the closest position of the brake lever. The slider is provided with a sliding body that slides in the up-down direction inside the slider. Brake pads that come into pressure contact with the left and right rear wheels when the brake lever is in the braking position are connected to the sliding body via wires, and when the brake lever is operated toward the braking position, the slider also approaches the steering unit, and when the brake lever is in the separated position, the slider also moves away from the steering unit; 3. The locking device for a pushcart according to claim 2, wherein the wire is connected to the lower end of the sliding body, and when the brake lever is operated toward the braking position, the sliding body abuts against the bottom of the slider via an elastic body that can expand and contract.

6. A slider is connected to the brake lever, and the slider moves linearly in the up-down direction between the separated position and the closest position of the brake lever. The slider is provided with a sliding body that slides in the up-down direction inside the slider. Brake pads that come into pressure contact with the left and right rear wheels when the brake lever is in the braking position are connected to the sliding body via wires, and when the brake lever is operated toward the braking position, the slider also approaches the steering unit, and when the brake lever is in the separated position, the slider also moves away from the steering unit; 5. The locking device for a pushcart according to claim 4, wherein the wire is connected to the lower end of the sliding body, and when the brake lever is operated toward the braking position, the sliding body abuts against the bottom of the slider via an elastic body that can expand and contract.

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