Mast for cargo lifting vehicle

Description

1 / 9 Mast for cargo lifting vehicle Technical Field

[0001] The present invention relates to a mast for a load lifting vehicle. Fundamentals of the Technique

[0002] A mast is the vertical assembly at the front of a load-lifting vehicle (such as a forklift) that performs the work of lifting, lowering, and tilting the load.

[0003] Attached to the mast is the trolley. Attached to the trolley are the forks. The trolley is usually actuated by a hydraulic cylinder in the middle of the mast. When an operator pulls a lever, it raises the trolley, actuating this cylinder, thus raising the forks (and any load on them). Known masts raise by hydraulic displacement and lower by gravity.

[0004] Free lift is the maximum height to which the forks can be raised without changing the mast height. It is important to observe the free lift, especially if there is a desire to stack or unstack in confined spaces, such as trailers, containers, and racking systems. These applications have height restrictions and could cause product or equipment problems and potential safety issues for operators or nearby pedestrians.

[0005] There are numerous types of masts, such as a simplex mast, a duplex mast, a triplex mast, and a quadruple mast. A simplex mast is the simplest type of mast. It is a single-stage mast with a single channel. The mast and trolley rise simultaneously. It is built in different sizes to accommodate various lifting heights. This mast has very limited or no free lift and is used for lower lifting heights. However, the simplex mast provides very good operating visibility. This is because it has fewer components inside it to obstruct the operator's view. Petition 870250094496, dated 10 / 16 / 2025, page 5 / 20 2 / 9

[0006] Returning to Figure 1, this shows a simplex mast 100 in both the lowered and raised positions, that is, when the car 101 is lowered and raised. It can be observed that even in the lowered position, the lowered height of the mast is relatively high. The lowered height, also known as the collapsed height, is the distance from the floor to the top of the mast when the car 101 is lowered. As is known in the art, the lowered height is especially important to consider if a vehicle with the mast attached is traveling through confined spaces, such as doorways.

[0007] When raised so that the car and forks are fully raised, the extended height of the mast is very high due to the high height of the car 101 and the extended cylinder 102. As is known in the art, the extended height is the distance from the floor to the top of the mast when the car 101 is fully raised. High extended heights interfere with overhead structures and raise the center of gravity of the mast, which affects the stability and capacity of a load-lifting vehicle on which the mast may be mounted.

[0008] Furthermore, the simplex mast shown in Figure 1 has no headroom and therefore has limited applications. Additionally, this mast requires a relatively long 102 cylinder, which can be expensive. Simplex masts are generally used in outdoor areas where headroom is not a concern.

[0009] There is a need for an improved simplex or single-stage mast that addresses the disadvantages of the previous technique. Summary

[0010] The present teachings relate to a mast for a load-lifting vehicle comprising two opposing rails connected at a mast base, a carriage configured to move along the rails, a mast cross member configured to move along the rails, a first hydraulic cylinder and second hydraulic cylinders connected to the mast cross member, wherein the first cylinder is Petition 870250094496, dated 10 / 16 / 2025, page 6 / 20 3 / 9 is configured to move the car relative to the mast cross member, and the second cylinders are configured to move the mast cross member, the first cylinder, and the car relative to the mast base.

[0011] This configuration provides free mast lift, where the first cylinder can lift the car without increasing the mast height. Furthermore, this configuration is a single-stage or simplex mast, so good visibility is provided because of the relatively few components that block an operator's view of the forks (and load).

[0012] Preferably, the car comprises two opposing sections and a car cross member connecting the opposing sections, the two opposing sections formed to slide within the mast rails.

[0013] This configuration provides a car generally in a U shape and this shape allows the car to be lifted by the first cylinder, i.e. the side section slides past the mast cross member when the first cylinder is actuated.

[0014] Preferably, one end of the piston rod of the first cylinder is connected to the cross member of the carriage and one head of the first cylinder is mounted on the cross member of the mast.

[0015] With this configuration, the first cylinder can be considered to be hanging from the mast cross member, which allows it to move with the car, i.e., to be raised and lowered with the car. Furthermore, by extending and retracting the piston rod, the car can be raised and lowered relative to the mast cross member.

[0016] The piston rod end of the first cylinder can be connected to the car's cross member using a spherical rod shackle.

[0017] Preferably, the piston rod ends of the second cylinders are connected to the mast cross member and the blank ends of the second cylinders are mounted on the mast base.

[0018] This configuration allows the second cylinders to retain the stationary mast cross member when the first cylinder Petition 870250094496, dated 10 / 16 / 2025, page 7 / 20 4 / 9 is extending, retracting, etc. Additionally, this allows the second cylinders to raise and lower the mast cross member when desired, which in turn raises the first cylinder and the carriage.

[0019] A piston rod in the first cylinder is configured to extend to raise the car and retract to lower the car.

[0020] The piston rods of the second cylinders can be configured to extend to raise the mast cross member, the first cylinder and the carriage and to retract to lower the mast cross member, the first cylinder and the carriage.

[0021] Optionally, the piston rods of the second cylinders are configured to extend only after the piston rod of the first cylinder is fully extended.

[0022] This ensures that the mast height is only raised after the maximum elevation using the first cylinder has been reached.

[0023] Optionally, the piston rod of the first cylinder is configured to extend only after the piston rods of the second cylinder are fully extended.

[0024] The second cylinders can be configured to hold the mast cross member stationary while the first cylinder moves the car relative to the mast cross member.

[0025] Preferably, the car cross member connects the two opposite sections at the first end of the car and a second end of the car, opposite the first end, is open. This allows the car to move relative to the mast cross member.

[0026] Preferably, the rails are connected by fixed support members that keep the rails parallel to each other. These provide support and stability to the mast.

[0027] The present teachings also provide another embodiment of a mast for a load-lifting vehicle comprising two opposing rails connected by a mast base, a Petition 870250094496, dated 10 / 16 / 2025, page 8 / 20 5 / 9 car configured to move along the rails, a mast cross member configured to move along the rails, two first hydraulic cylinders and a second single hydraulic cylinder connected to the mast cross member, wherein the first two cylinders are configured to move the car relative to the mast cross member and the second single cylinder is configured to move the mast cross member, the first cylinder and the car relative to the base of the mast.

[0028] This embodiment functions essentially the same way as the first embodiment and has all the same advantages. Instead of a single centrally mounted cylinder, configured to move the car relative to the mast cross member, two cylinders mounted adjacently on respective rails are provided. Instead of two cylinders adjacent to their respective rails configured to move the mast cross member, the first cylinder and the car relative to the mast base, a single centrally mounted cylinder is provided to perform the same function.

[0029] The mast configurations, according to the present teachings, provide a relatively low collapsed height, provide free lift, and are economical due to the use of relatively basic and well-known components in the art. Furthermore, the use of these components, in particular the use of the first and second hydraulic cylinders, provides a very reliable configuration. Pulleys or chains, which require more maintenance and can fail, are not required. In addition, unlike some configurations of the prior art, a telescopic cylinder is not required, and the mast, according to the present teachings, relies on well-known single-stage hydraulic cylinders. Brief Description of the Figures

[0030] The invention will now be illustrated by the following description of embodiments thereof, given only by way of example, with reference to the accompanying drawings, in which:

[0031] Fig. 1 shows a known simplex mast in both Petition 870250094496, dated 10 / 16 / 2025, page 9 / 20 6 / 9 positions lowered and raised;

[0032] Fig. 2 shows the mast in accordance with the present teachings in the fully lowered position;

[0033] Fig. 3 shows the mast in accordance with teachings in a semi-elevated position;

[0034] Fig. 4 shows the mast in accordance with the present teachings in a fully elevated position;

[0035] Fig. 5 shows side views of the mast according to the present teachings in a fully lowered position, a semi-raised position and a fully raised position; and

[0036] Fig. 6 shows additional views of the mast in accordance with the present teachings. Detailed Description of Preferred Options

[0037] With reference to Fig. 2, this shows the mast 200 according to the present teachings in a lowered position; The mast 200 comprises two opposing rails 201. The rails are connected by fixed support members 202, which maintain the rails at a fixed distance (parallel) and provide support and stability to the mast 200. The mast further comprises a carriage 203 configured to slide within the rails, i.e., to move up and down within the opposing rails. For example, the opposing rails may provide channels, which are similar in appearance to I-beams. The rails provide a guide for the carriage 203 to pass through. As is known in the art, forks 204 may be mounted on the carriage.

[0038] With reference to Fig. 3, this shows the mast 200 according to the present teachings in a semi-elevated position; this is achieved through the use of a central cylinder or first cylinder 301. The first cylinder 301 is mounted on a mast cross member 302. The mast cross member spans the distance between the rails 201 and is configured so that the side sections 303 of the carriage 203 slide between the respective rails 201 and the mast cross member 302. In particular, the Petition 870250094496, dated 10 / 16 / 2025, page 10 / 20 7 / 9 The head of the first cylinder is mounted on the mast cross member 302 so that a piston rod 304 of the first cylinder passes through the mast cross member 302. The first cylinder 301 is mounted only on its head to the mast cross member, so that the blind end of the first cylinder 301 is disassembled or hanging. The first cylinder 301 is positioned centrally, that is, approximately equidistant from each rail 201. The piston rod 304 extending from the first cylinder 301 is connected to a carriage cross member 305. The carriage cross member 305 and the aforementioned side sections 303 connected to it form the carriage 203. Specifically, the carriage cross member 305 spans the distance between the rails and connects to each side section 303 at the first end of the carriage. A second end of the carriage 203, opposite the first end, is open.When the car is fully lowered, as shown in Fig. 2, the car cross member 305 rests on the mast cross member 302.

[0039] The extension of the piston rod 304 of the first cylinder raises the car 203, causing it to slide along the rails 201, specifically the side sections 303 slide along the rails. The first cylinder 301 is configured to move the car 203 relative to the mast cross member 302. The forks 204 attached to the car 203 rise with the car along with any load on the forks. As will be explained below, the mast cross member 302 is held in place (stationary) when the piston rod 304 of the first cylinder 301 is extending and retracting. In the preferred embodiment, the piston rod 304 of the first cylinder is connected to the car cross member 305 using a spherical rod shackle, but any known means of connection may be used.

[0040] It should be noted from Fig. 3 that the carriage 203 (and the forks 204) can lift up to approximately half the height of the mast 200 without increasing the height of the mast. That is, the mast 200, according to current teachings, offers a considerable amount of free lift. Petition 870250094496, dated 10 / 16 / 2025, page 11 / 20 8 / 9

[0041] Going back to Fig. 4, this shows car 203 fully raised. This is achieved by two external cylinders or second hydraulic cylinders 401. Each second cylinder 401 is positioned adjacent to a respective rail 201. A piston rod 402 extends from a first end of each second cylinder and connects to the mast cross member 302. The opposite end or second end of each second cylinder 401 is connected to a base 403 of the mast 200. The base 403 connects the two rails 201. The mast is configured in such a way that, when the piston rods 402 extend, they raise the mast cross member 302, as well as the carriage 203, which is connected to the mast cross member 302 by the first cylinder 301, the first cylinder also being raised by the extension of the second cylinders 401. That is, the carriage 203 is moved relative to the base 403 of the mast by the second cylinders 401.The mast is configured so that when the second cylinders extend, they raise the car above the mast height by 200, that is, the fully raised car increases the height of the mast.

[0042] In Fig. 5, the free lifting capacity of the aforementioned 200 mast can also be seen, according to the present teachings. For example, a vehicle, such as a forklift with the 200 mast mounted on it, can enter a confined space, such as a shipping container, and lift a load without increasing the height of the mast. Later, when the vehicle has left the confined space, it can lift the load to the maximum stacking height, etc.

[0043] Fig. 6 shows additional views of mast 200 according to the present teachings. The mast may be considered to be a two-stage mast or a pseudo two-stage mast. The first stage 601 is when the first cylinder extends and retracts to raise and lower the carriage 203 relative to the mast cross member. The second stage 602 is when the second cylinders extend and retract to raise and lower the mast cross member, the carriage, and the first cylinder relative to the mast base. The expert in the field will observe that the second stage may occur 602 before Petition 870250094496, dated 10 / 16 / 2025, page 12 / 20 9 / 9 of the first stage 601. That is, the second cylinders can lift the car before the first cylinder extends. This will still achieve the same free lift outlined above, where the first cylinder extends first.

[0044] Fig. 6 shows views of only the mast cross member 302 and cylinders 301, 401 to show these components more clearly. The mounting of the first cylinder 301 on the mast cross member 302 can be seen, where the first cylinder is suspended by the head of the first cylinder from the mast cross member 302. The mast cross member 302 and the first cylinder 301 can be raised and lowered by the second cylinders 401. Flexible hydraulic supply lines 603 are provided to accommodate the raising and lowering of the first cylinder 301. Furthermore, the good visibility afforded to an operator of the mast 200 can be observed from Fig. 6.

[0045] The specialist in the field will observe that the present teachings are not limited to the configuration shown in Figures 2 to 6 and that the positions of the hydraulic cylinder can be changed. For example, two cylinders could be used in place of the first cylinder and these cylinders positioned adjacent to the rails, i.e., two cylinders could be used for the first stage 601. A single cylinder, mounted centrally, could be used for the second stage. Essentially, the configuration of the first cylinder 301 and the configuration of the second cylinders 401 could be interchanged. Other variations are possible, such as two cylinders for each of the first stage 601 and the second stage 602. This could result in the four cylinders being positioned adjacent to the rails, which could provide improved visibility in the central area of ​​the mast 200.

[0046] The cylinder can be single-acting (actuated only when extended) or double-acting (actuated both when extended and retracted).

[0047] The invention is not limited to the embodiments described in this document, which may be varied within the scope of the claims that follow. Petition 870250094496, dated 10 / 16 / 2025, page 13 / 20

Claims

1 / 3 CLAIMS 1. Mast for a load lifting vehicle, characterized by comprising: two opposing rails connected by a base; a car configured to move along the rails; a mast cross member configured to move along the rails; a first hydraulic cylinder and second hydraulic cylinders connected to the mast cross member; wherein the first cylinder is configured to move the car relative to the mast cross member and the second cylinders are configured to move the mast cross member, the first cylinder and the car relative to the base.

2. Mast, according to claim 1, characterized in that the carriage comprises two opposing sections and a carriage cross member connecting the opposing sections, the two opposing sections being formed to slide within the mast rails.

3. Mast, according to claim 2, characterized in that one end of the piston rod of the first cylinder is connected to the cross member of the carriage and one head of the first cylinder is mounted to the cross member of the mast.

4. Mast, according to claim 3, characterized in that the piston rod end of the first cylinder is connected to the car's cross member using a spherical rod shackle.

5. Mast, according to any one of claims 1 to 4, characterized in that the piston rod ends of the second cylinders are connected to the mast cross member and the blind ends of the second cylinders are mounted on the base.

6. Mast, according to any one of claims 1 to 5, characterized in that a piston rod of the first cylinder is configured to extend to raise the car and retract to lower the car.

7. Mast, according to claim 6, characterized in that the piston rods of the second cylinders are configured to extend to raise the mast cross member, the first cylinder and the carriage and to retract to lower the mast cross member, the first cylinder and the carriage.

8. Mast, according to claim 7, characterized in that the piston rods of the second cylinders are configured to extend only after the piston rod of the first cylinder is fully extended.

9. Mast, according to claim 7, characterized in that the piston rod of the first cylinder is configured to extend only after the piston rod of the second cylinder is fully extended.

10. Mast, according to either claim 1 or 9, characterized in that the second cylinders are configured to hold the mast cross member stationary while the first cylinder moves the car relative to the mast cross member.

11. Mast, according to claim 2, characterized by the car's transverse member connecting the two opposite sections at the first end of the car and a second end of the car, opposite the first end, being open.

12. Mast, according to any one of claims 1 to 12, characterized in that the rails are connected by fixed support members that keep the rails parallel to each other.

13. Mast for a load-lifting vehicle, characterized by comprising: two opposing rails connected by a base; a car configured to move along the rails; a mast cross member configured to move along the rails; two first hydraulic cylinders and a single second hydraulic cylinder connected to the mast cross member; wherein the first two cylinders are configured to move the car relative to the mast cross member and the second cylinder is configured to move the mast cross member, the first cylinder and the car relative to the base.

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