JP7511910B2 - Roll Grab - Google Patents

Description

The present invention relates to a roll grab, an attachment that is attached to the end of the lift arm of a front loader and is used to transport roll bales of cut grass.

Conventionally, roll grabs have been used as attachments for transporting, stacking, and unloading roll bales, which are cylindrical rolls of cut grass. They are attached to the lift arms of front loaders used with buckets and forks to grip both sides of the roll bale.

For example, this roll grab opens and closes the gripping arms using the driving force of a hydraulic cylinder installed in the roll grab body (see Patent Documents 1-7).

Japanese Patent Application Laid-Open No. 64-71416 Japanese Utility Model Application Publication No. 3-18728 Japanese Patent Application Laid-Open No. 3-87115 Japanese Utility Model Application Publication No. 4-12726 JP 2000-170198 A JP 2005-117984 A (Patent No. 4467943) JP 2008-308327 A (Patent No. 4,890,359)

However, the above-mentioned roll grab has a hydraulic cylinder in the roll grab body, which increases the weight of the roll grab body, making it difficult to attach and detach it from the end of the arm or to use it on a small front loader used for transporting work in narrow spaces.

Therefore, the present invention aims to provide a roll grab that is lightweight and can be easily attached and detached to the tip of the lift arm of a front loader.

In view of the above problems, the present invention provides a roll grab used to grip both sides of a roll bale, comprising: a frame- shaped main body frame fixed via a first link and an attachment part to an extendable rod of a hydraulic cylinder provided at the end of a lift arm of a front loader; two gripping arms rotatably supported on the left and right sides of the main body frame; and a link mechanism that includes the first link and links the extension and retraction movement of the hydraulic cylinder of the lift arm with the opening and closing movement of the two gripping arms.

In addition to the above-mentioned configuration, it is preferable that the link mechanism has a first link, the upper end of which is connected to the telescopic rod of the hydraulic cylinder and the lower end of which is connected to the lower stay of the mounting part on the main body frame, and which swings in the front-rear direction following the telescopic movement of the telescopic rod, a second link connected to the upper end of the first link and converts the swinging movement of the first link into reciprocating movement in the front-rear direction, and a third link connected to the second link and the base end of the gripping arm.

In addition to the above-mentioned configuration, it is preferable that the second link is formed in a substantially T-shape when viewed from a planar direction, and has a rear end connected to the upper end of the first link, and a side end extending in the left-right direction from the front end and connected to the third link.

In addition to the above-mentioned configuration, it is preferable that the mounting portion has a lower stay that protrudes toward the rear of the frame and fixes the first link from below so that it can swing freely, and an upper stay that fixes an auxiliary arm that connects the roll grab to the lift arm to keep the entire roll grab in a horizontal position.

According to the present invention described above, by providing a link mechanism that links the opening and closing movement of the gripping arm with the extension and contraction movement of the hydraulic cylinder of the front loader's lift arm, it is possible to reduce the weight of the roll grab body and make it easier to handle, such as attaching it.

FIG. 1 is a perspective view showing an example of an embodiment of a roll glove of the present invention. FIG. 2 is a plan view of FIG. 1 . FIG. 2 is a side view of FIG. 1 . FIG. 2 is a side view showing a state in which the roll grab of FIG. 1 is attached to the tip of a lift arm. 2A is a plan view of the link mechanism and its surroundings during the closing operation of the roll grab of FIG. 1 , and FIG. 2B is a side view of the link mechanism and its surroundings. 2A is a plan view of the link mechanism and its surroundings during the opening operation of the roll grab of FIG. 1 , and FIG. 2B is a side view of the link mechanism and its surroundings during the opening operation of the roll grab of FIG. 1 .

(Embodiment)
An example of a roll grab 1 according to an embodiment of the present invention will be described in detail with reference to Figures 1 to 6. In this embodiment, as shown in Figure 1, the gripping arms 20, 20 side of the roll grab 1 are in the front direction, and the mounting portion 12 side is in the rear direction.

The roll grab 1 is mainly composed of a main frame 10 that is fixed to the tip of the lift arm 51 of the front loader 50 via an attachment part 12, gripping arms 20, 20 that are pivotally supported on the main frame 10, and a link mechanism 30 that links the extension and retraction movement of the hydraulic cylinder 52 of the lift arm 51 with the opening and closing movement of the gripping arms 20, 20.

The main frame 10 has a horizontally long, roughly rectangular frame body 11 and pivotal support parts 13, 13 that pivotally support the gripping arms 20, 20 on the left and right sides of the frame body 11, and a first link 31 and an auxiliary arm 40 of the link mechanism 30, which will be described later, are fixed via an attachment part 12 that protrudes rearward from the frame body 11. The pivotal support parts 13, 13 are fixed at a position slightly diagonally rearward from the left and right sides of the frame body when viewed from a plan view.

More specifically, the mounting portion 12 has a lower stay 12a that fixes the first link 31 from below so that it can swing back and forth, and an upper stay 12b that fixes the auxiliary arm 40 that connects the lift arm 51 to the first link 31 to keep the entire roll grab 1 in a horizontal position.

The gripping arms 20, 20 have an arm portion 21 that connects to the third links 33, 33 of the link mechanism 30 described below, and a gripping portion 22 that presses the roll bale R, which is the object to be gripped, from the side.

The arm portion 21 is formed of an approximately L-shaped angular frame when viewed from the planar direction, and has a first pin 21b journaled on the support portions 13, 13 of the main frame 10 at the bent intermediate position, and a second pin 21c journaled on the first link 31 on the base end portion 21a side.

The gripping portion 22 is roughly rectangular when viewed from the side, and is made of a roughly L-shaped frame of round pipe material that is bent inward from the planar direction.

The link mechanism 30 has a first link 31, the upper end of which is connected to the telescopic rod 53 of the hydraulic cylinder 52 of the lift arm 51, and a lower end which is connected to the lower stay 12a of the mounting part 12 on the main frame 10, and which swings in the front-rear direction following the telescopic movement of the telescopic rod 53, a second link 32 which is connected to the upper end of the first link 31 and converts the swinging movement of the first link 31 into a reciprocating movement in the front-rear direction, and third links 33, 33 which are connected to the second link 32 and the base end of the gripping arm 20.

The first link 31 has an upper end 31a connected to the telescopic rod 53 of the hydraulic cylinder 52 of the lift arm 51, and a lower end 31b connected to the lower stay 12a of the mounting part 12 so that it can swing freely. The upper end 31a of the first link 31 swings in the front-rear direction around the lower end 31b. It is also preferable that the upper end 31a is formed at an incline so that the connection position with the telescopic rod 53 and the connection position with the second link 32 are connected at different heights.

The second link 32 is formed in a roughly T-shape when viewed from the planar direction, and has a rear end 32a connected to the upper end 31a of the first link 31, and side ends 32b, 32b connected to the third link 33 extending in the left-right direction from the front end 32c. These side ends 32b, 32b have a pin 32d that pivotally supports the third link 33. It is preferable that this second link 32 reciprocates in the front-rear direction at least within a range that does not protrude forward beyond the frame body 11 of the main frame 10.

The third links 33, 33 are rotatably connected to the side ends 32b, 32b of the second link 32, and are horizontally elongated flat plates with bearing holes formed at both ends. They are rotatably connected to the pins 32d, 32d of the side ends 32b, 32b of the second link 32 and the second pin 21c on the base end 21a side of the gripping arms 20, 20.

Next, the opening and closing operation of the roll grab that grips the roll bale R will be explained with reference to Figures 4-6.

As shown in FIG. 4, the roll grab 1 is attached to the tip of the lift arm 51 of the front loader 50, and the operation setting of the telescopic rod 53 of the hydraulic cylinder 52 of the lift arm 51 is controlled by a switch or the like provided at the operator's seat, etc.

For example, when closing the gripping arms 20, 20 to press and grip the side of the roll bale R, as shown in FIG. 5, the operator sets the telescopic rod 53 of the hydraulic cylinder 52 of the lift arm 51 to contract. At this time, the first link 31 in the link mechanism 30 rotates rearward, and the second link 32 moves back following the first link 31. Then, the base ends 21a, 21a of the gripping arms 20, 20 also move back following via the third links 33, 33, so that the gripping parts 22, 22 rotate inward and press against the side of the roll bale R, thereby gripping and lifting it.

When opening the gripping arms 20, 20 to move the gripping parts 22, 22 away from the side of the roll bale R, the operator sets the telescopic rod 53 of the hydraulic cylinder 52 of the lift arm 51 to extend, as shown in FIG. 6. At this time, the first link 31 in the link mechanism 30 rotates forward, and the second link 32 moves forward following the first link 31. Then, the base end 21a of the arm part 21 also moves forward following the first link 31 via the third links 33, 33, causing the gripping parts 22, 22 to rotate outward, allowing the roll bale R to be lowered away from the side.

Although not shown, an auxiliary arm 40 consisting of multiple link members can be connected to the upper stay 12b of the mounting portion 12 on the main frame 10 and the lift arm 51 to function as a parallel link mechanism, so that the roll grab 1 can be kept horizontal when stacking or unloading roll bales R.

Therefore, the above-mentioned roll grab 1 is equipped with a link mechanism that links with the hydraulic cylinder 52 of the lift arm 51 of the front loader 50 used for buckets, forks, etc., making it possible to reduce the weight of the roll grab 1 body and make it easier to attach and detach.

The above embodiment illustrates a preferred embodiment of the present invention, but the present invention is not limited to the above embodiment, and improvements and modifications are possible within the scope of the claims.

1 roll grab,
10 Main body frame, 11 Frame body, 12 Mounting portion, 12a Lower stay, 12b Upper stay, 13 Axle support portion,
20 gripping arm, 21 arm portion, 21a base end portion, 21b first pin, 21c second pin, 22 gripping portion,
30 Link mechanism, 31 First link, 31a Upper end, 31b Lower end, 32 Second link, 32a Rear end, 32b Side end, 32c Front end, 32d Pin, 33 Third link,
40 Auxiliary arm,
50 Front loader, 51 Lift arm, 52 Hydraulic cylinder, 53 Telescopic rod,
R roll bale.

Claims (4)

A roll grab used to grip both sides of a roll bale,
A roll grab characterized by comprising : a frame-shaped main body frame fixed via a first link and an attachment part to an extendable rod of a hydraulic cylinder provided at the tip of a lift arm of a front loader; two gripping arms rotatably supported on the left and right sides of the main body frame; and a link mechanism including the first link, which links the extendable and retractable action of the hydraulic cylinder with the opening and closing action of the two gripping arms. The roll grab according to claim 1, characterized in that the link mechanism has a first link, the upper end of which is connected to the telescopic rod of the hydraulic cylinder and the lower end of which is connected to the lower stay of the mounting part of the main body frame, and which swings in the forward and backward directions following the telescopic movement of the telescopic rod, a second link, which is connected to the upper end of the first link and converts the swinging movement of the first link into a reciprocating movement in the forward and backward directions, and a third link, which is connected to the second link and the base end of the gripping arm. The roll grab of claim 2, characterized in that the second link is formed in a roughly T-shape when viewed from the planar direction, and has a rear end connected to the upper end of the first link, and a side end extending in the left-right direction from the front end and connected to the third link. The roll grab according to any one of claims 1 and 2, characterized in that the mounting portion is provided in a rearward direction of the frame body and has a lower stay that fixes the first link from below so that it can swing freely, and an upper stay that fixes an auxiliary arm that connects between the lift arm and the roll grab to keep the entire roll grab in a horizontal position.

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