Single handrail telescopic ladder

Abstract

A single handrail telescopic ladder is provided. Which includes front tubes and rear tubes that are hinged to each other at a top; a single handrail tube that is scalability inserted into one of the front tubes; the front tubes are provided with a fixing hole, and a locking hole corresponding to the fixing hole is provided at a corresponding position of the single handrail tube; locking members pass through the fixing hole and the locking hole when the single handrail tube is pulled out from the front tubes to a predetermined position; and an elastic member that directly or indirectly acts on the locking members and provides a pre-tension force for the locking member; when the locking members are unlocked, the locking members exit from the fixing hole and/or locking hole, allowing the single handrail tube to automatically retract into the front tubes.

Claims

1. A single handrail telescopic ladder, comprising: two front tubes and two rear tubes, wherein one of the two front tubes and one of the two rear tubes at the same side are hinged at a top; pedals for a user to step on are provided between adjacent front tubes and between adjacent rear tubes; a single handrail tube, which is scalability inserted into one of the two front tubes; one of the two front tubes is provided with a fixing hole that penetrates both inside and outside, and a locking hole corresponding to the fixing hole is provided at a corresponding position of the single handrail tube; a locking member, which simultaneously passes through the fixing hole and the locking hole after the single handrail tube is pulled out from one of the two front tubes to a predetermined position, thereby achieving a fixation between the single handrail tube and one of the two front tubes; and an elastic member, which directly or indirectly acts on the locking member and provides a pre-tension force for the locking member towards a direction passing through the fixing hole and the locking hole; when the locking member is unlocked, the locking member exits from the fixing hole and locking hole, allowing the single handrail tube to automatically retract into one of the two front tubes; wherein an installation seat is fixedly provided on an outer wall of one of the two front tubes, and a button is provided on the installation seat, wherein the elastic member is a spring; wherein a guide structure is provided between the button and the installation seat, and the guide structure is provided with a guide hole configured for one end of the spring to insert and a guide protrusion configured for the other end of the spring to be sleeved.

2. The single handrail telescopic ladder according to claim 1, wherein a middle of the button is provided with an arc-shaped protrusion extending towards the installation seat, an outer side of a front end of the arc-shaped protrusion is provided with a chamfered slope, a middle of the arc-shaped protrusion is provided with a rotating shaft hole, the installation seat is provided with a rotating shaft passing through the rotating shaft hole, so that the button is rotatably connected to the installation seat; one end of the button is provided with the locking member that is inserted into the fixing hole and the locking hole, and the other end of the button interacts with the elastic member, wherein the spring applies elastic force to the other end of the button, so that the button is caused to rotate around a middle and the locking members is driven to have a pre-tension force to move in a direction passing through the fixing hole and the locking hole.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a schematic structural diagram of a ladder in an embodiment.

(2) FIG. 2 is a sectional view of an installation seat in an embodiment.

(3) FIG. 3 is a schematic structural diagram of a ladder in another embodiment.

(4) FIG. 4 is a sectional view of an installation seat in another embodiment.

(5) FIG. 5 is a schematic structural diagram of a button.

(6) FIG. 6 is a schematic structural diagram of the installation seat after removing the button.

(7) FIG. 7 is a schematic structural diagram using a pressing plate in yet one embodiment.

(8) FIG. 8 is a sectional view of the pressing plate in FIG. 7.

(9) FIG. 9 is a schematic structural diagram of the pressing plate in FIG. 7.

(10) FIG. 10 is a sectional view of the pressing plate after the front and rear tubes are closed.

(11) FIG. 11 is a sectional view of the pressing plate of still one embodiment.

(12) Numeral reference: 1front tube; 11fixing hole; 2rear tube; 3pedal; 4installation seat; 41rotating shaft; 5locking member; 51circular pull ring; 52pin shaft; 521thin section; 522thick section; 523step surface; 53spring; 54leaf spring; 6single handrail tube; 61locking hole; 7button; 71shaft hole; 72guide protrusion; 73guide hole; 74chamfered slope; 75arc-shaped protrusion; 8pressing plate; 81avoidance hole; 82limit protrusion; 83convex shaft; 84contact protrusion.

DESCRIPTION OF EMBODIMENTS

(13) The present disclosure will be further described based on the accompanying drawings and specific embodiments.

(14) As shown in FIGS. 1 and 2, this embodiment discloses a single handrail telescopic ladder, which includes two pairs of front tubes 1 and two pairs of rear tubes 2. The front tubes 1 and the rear tubes 2 are hinged to each other at a top to form a zigzag folding structure. Pedals 3 configured for a user to step on are provided between adjacent front tubes 1 and adjacent rear tubes 2. A hollow single handrail tube 6 can be inserted and retracted into one of the front tubes 1. The single handrail tube 6 is used for a user to grip when climbing up or down a ladder. At a top position of the front tubes, there is a fixing hole 11 that penetrates both inside and outside, and at a corresponding position of the single handrail tube 6, there is a locking hole 61 that corresponds to the fixing hole 11.

(15) An installation seat 4 is fixedly provided on an outer wall of the front tubes 1 with the single handrail tube 6, and the rear tubes 2 are hinged to the installation seat 4. Locking members 5 are provided on an inner wall of the installation seat 4, and the locking members 5 is a pull ring pin. The pull ring pin includes a circular pull ring 51 provided on an outer side of the installation seat 4, and a pin shaft 52 provided on an inner side of the installation seat 4 and insertable into the fixing hole 11 and the locking hole 61. The pin shaft 52 includes a thin section 521 and a thick section 522 from outside to inside, and a step surface 523 is formed between the thin section 521 and the thick section 522. The elastic member is a spring 53, the spring 53 is provided inside the installation seat 4. The spring 53 is sleeved onto the thin section 521, and one end of the spring 53 is in contact with the step surface 523, and the other end thereof is in contact with an inner wall of the installation seat 4, thereby applying a pre-tension force to the entire pull ring pin towards an inner side of the ladder.

(16) When the user pulls out the single handrail tube, the pin shaft 52 will pass through the fixing hole 11 and the locking hole 61 under an action of the spring 53, thereby supporting the single handrail tube 6 and maintaining its extended state. When the single handrail tube 6 is needed for storage, the circular pull ring 51 is simply pulled outward to realize the unlocking.

(17) As shown in FIGS. 3, 4, 5, and 6, in an implementation mode, a button 7 is provided on an inner wall of the installation seat 4. A middle of the button 7 is provided with an arc-shaped protrusion 75 extending towards the installation seat 4. An outer side of a front end of the arc-shaped protrusion 75 is provided with a chamfered slope 74, and a middle end thereof is provided with a shaft hole 71. The installation seat 4 is provided with an accommodation space configured for accommodating the button 7, and a rotating shaft 41 passing through the shaft hole 71 is provided on a wall of the accommodation space, thereby enabling the button 7 to rotate around its middle. An upper end of the button 7 is provided with the locking members 5 that can be inserted into the fixing hole 11 and the locking hole 61, and a lower end thereof interacts with a spring 53. The spring 53 applies an elastic force to a lower end of the button 7, and the button 7 is caused to rotate around its center and the locking members 5 is driven to have a pre-tension force towards a direction passing through the fixing hole 11 and the locking hole 61.

(18) A guide structure is provided between the lower end of the button 7 and the installation seat 4. The guide structure includes a guide hole 73 on an inner side of the button 7 configured to insert one end of the spring 53, and a guide protrusion 72 provided inside the installation seat 4 and configured for the other end of the spring 53 to be sleeved.

(19) When the user pulls out the single handrail tube, the locking members 5 will pass through the fixing hole 11 and the locking hole 61 under an action of the spring 53, thereby supporting the single handrail tube 6 and maintaining its extended state. When the single handrail tube 6 is needed for storage, the button 7 is simply pressed to realize the unlocking.

(20) As shown in FIGS. 7 to 10, in an implementation mode, a pressing plate 8 is provided on a wall of the front tubes 1 facing the rear tubes 2, and an overall shape of the pressing plate 8 is a U-shaped structure that matches an outer wall contour of the front tubes 1. Convex shafts 83 extending inward are provided in a middle of two opposite side walls of the U-shaped pressing plate 8. The convex shafts 83 are inserted into the front tubes 1 to achieve a rotational connection between the pressing plate 8 and the front tubes 1. An inner side of an upper end of the pressing plate 8 is provided with the locking members 5, and the locking members 5 are integrally formed with the pressing plate 8. An inner side of a lower end of the pressing plate 8 is provided with a spring 53, and the spring 53 applies an elastic force to the pressing plate 8, and the pressing plate 8 is caused to rotate around its middle and the locking members 5 at the upper end is driven to have a pre-tension force that moves in a direction of passing through the fixing hole 11 and the locking hole 61.

(21) One side of the front tubes 1 corresponding to the pressing plate 8 is provided with a limit protrusion 82 extending towards the pressing plate 8. The spring 53 is sleeved onto the limit protrusion 82, and the pressing plate 8 is provided with an avoidance hole 81 at a position corresponding to the limit protrusion 82. A length of the limit protrusion 82 is less than or equal to a thickness of the pressing plate 8. After the front tubes 1 and the rear tubes 2 are combined to compress the pressing plate 8, the limit protrusion 82 will enter the avoidance hole 81.

(22) After the ladder is folded, the front tubes 1 and the rear tubes 2 are combined to compress the pressing plate 8 to overcome the pre-tension force of the spring 53, so that the locking members 5 can at least exit from the locking hole 61 of the single handrail tube 6, thereby completing an unlocking of the single handrail tube 6 and achieving a storage of the single handrail tube 6. When the ladder is unfolded, the user can directly pull out the single handrail tube 6 outward. When the locking hole 61 is moved to align with the fixing hole 11, the locking members 5 will be instantly inserted into the locking hole 61, thus completing a locking of the single handrail tube 6.

(23) As shown in FIG. 11, in an implementation mode, an upper end of the pressing plate 8 can be rotatably connected to the front tubes 1 by providing the convex shafts 83. An inner side of the lower end of the pressing plate 8 is provided with a contact protrusion 84 extending towards the front tubes 1. The locking members 5 and the elastic member are located inside the single handrail tube 6. The locking members 5 passes through the locking hole 61 and the fixing hole 11 from inside to outside and extends to the outside of the front tubes 1 to contact with the contact protrusion 84. In an implementation mode, the elastic member adopts a V-shaped leaf spring 54, and the locking members 5 are protrusions that are provided on the leaf spring 54 and integrally formed with the leaf spring 54.

(24) When the ladder is folded, the front tubes 1 and the rear tubes 2 are combined to compress the pressing plate 8, so that the contact protrusion 84 compresses the locking members 5 inward to overcome the pre-tension force of the leaf spring 54, and the locking members 5 are caused to at least exit from the fixing hole 11 of the front tubes 1. Thus, unlocking the single handrail tube 6 and achieving storage of the single handrail tube 6.