Detailed statement

Abstract

The swing frame roll clamp can include a mounting plate mountable to a lift truck and a pair of opposing clamp arms that can be configured to selectively and alternately grip and release a cylindrical load, and each opposing clamp arm can be either a short arm or a long arm relative to the other opposing clamp arm.

Description

[Background technology]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS]

[0002]

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 376,731, filed September 22, 2022. BACKGROUND

[0003]

[0002] The present disclosure relates to roll clamps, and more particularly to a vehicle-mountable swinging frame roll clamp apparatus for engaging, transporting, and stacking rolls of paper and other materials.

[0004] Swivel-arm roll clamps designed for mounting on lift trucks and other vehicles are widely used to handle rolls of paper products, such as newsprint and kraft paper, as well as other materials. Swivel-arm roll clamps allow paper rolls or other cylindrical loads to be gripped or released from either a long-arm / short-arm configuration or an equal-arm configuration. Typically, roll clamps are rotatable to engage, transport, and deposit rolls with the roll's longitudinal axis either vertical or horizontal. When the roll is resting on a surface with its axis horizontal (referred to as a "bilge position"), a long-arm / short-arm configuration is preferably used, where the horizontally oriented upper arm of the clamp attachment extends further forward of the lift vehicle than the lower arm. This allows the upper arm to overreach the roll, allowing clamp pads on the ends of the upper and lower arms to engage the roll in diametrically opposed positions without the lower arm needing to be pushed under the roll, which could potentially cause the roll to roll away from the clamp. On the other hand, when rolls are transported or stacked with their longitudinal axes vertical, it is often preferable to use an equal arm configuration in which the arms on either side of the roll extend equally forward of the lift vehicle to facilitate insertion of the arms between closely adjacent rolls without damage. However, even when gripping or releasing rolls in a vertical orientation, it may be useful to use a long arm / short arm configuration if the rolls are gripped or released from a position adjacent a wall or other surface.

[0005] Existing swing frame paper roll clamps, such as the one disclosed in U.S. Pat. No. 4,435,119, allow clamp arms on either side of the clamp attachment to be moved toward or away from the vehicle. The rotor is mounted on a lift truck or other vehicle, and the swing frame clamp's faceplate is attached to the rotor's bearing furthest from the lift vehicle. The faceplate is a large monolithic plate containing multiple holes for fasteners to secure the faceplate to the rotor's bearing and defining a large central opening through which the rotary hydraulic connection is mounted. Upper and lower subframes, generally having an I-beam cross section, are welded to the faceplate above and below each subframe and pivotally attached to the faceplate by pins that engage respective pairs of support blocks projecting from the faceplate. The clamp arms are pivotally attached to the subframes and are rotated to clamp or release a load by hydraulic clamp rams connected to the clamp arms and one of the subframes, respectively. Extension or retraction of swing frame hydraulic rams attached to the faceplate and subframe causes the subframe to pivot about their central connection to the faceplate to swing the opposite ends of the subframe and attached clamp arms closer or farther from the lift truck.

[0006] Hydraulic fluid from the lift truck flows through a rotary hydraulic connection in the center of the faceplate, from which it enters conduits arrayed across the faceplate's surface and flows to the clamp's various hydraulic rams. The eight conduits supplying hydraulic fluid to the clamp rams are complex, each including a U-shaped piping section connected to a flexible hose section. Each piping section includes a first length of piping extending from the central rotary hydraulic connection toward the side of the faceplate opposite the clamp ram to which the conduit ultimately connects. A second length of piping extends perpendicular to the first length toward either the top or bottom of the faceplate. On either side of the central pivot, a portion of the innermost flange of each subframe is provided with a relief to allow the second length of piping to extend from the center of the faceplate to a point behind the web of the I-shaped subframe. A third length of piping, bent perpendicular to the second length, extends the conduit behind the web of each subframe toward the lateral center of the faceplate, where the piping is attached to a hose connected to one of the clamp rams. The hose allows the conduit to accommodate the motion of the clamp ram as it swings relative to the faceplate when the clamp arm is pivoted. Reliefs in the subframe flanges to accommodate the conduit feeding the clamp rams concentrate stress on the flanges, and because the conduit is attached to the faceplate behind the subframe, it is difficult to access for assembly or repair, such as replacing worn hose sections.

[0007] As previously mentioned, swinging frame roll clamp attachments mounted on lift tacks or other vehicles are used to grip and reposition roll-form products or other cylindrical loads. Such loads can be gripped and deposited from different orientations: a vertical orientation, in which the roll stands on one of its two flat ends, or a horizontal (“bilge”) orientation, in which the roll rests on its curved surface. Vehicle operators often do not know whether a load should be gripped or released from an equal-arm or long-arm / short-arm configuration until the load or destination, respectively, is reached. Similarly, even when a long-arm / short-arm configuration is used, operators often do not know on which side of the vehicle the short arms should be positioned until the load or destination is reached. Often, rolls or other such cylindrical loads are stored in enclosed areas where the vehicle has very little maneuvering space to change the clamp arm configuration, making it difficult for operators to properly position the load. Therefore, what is desired is an improved swinging frame roll clamp that offers improved maneuverability. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 shows a side elevation view of a swing frame roll clamp and a portion of a fork lift truck in a bilge position. [Figure 2] FIG. 2 shows a partial front view with portions removed to reveal the underlying structure of the swing frame roll clamp of FIG. 1 rotated to engage the roll on its vertical center axis. [Figure 3] FIG. 3 shows a cross-sectional view of the swing frame roll clamp of FIG. 2 taken along line AA. [Figure 4] FIG. 4 shows a prior art swing frame roll clamp having rollers and swing cylinders positioned so that the roll clamp is in an equal arm position. [Figure 5A]FIG. 5A shows the roll clamp of FIG. 4 with the swing cylinder positioned so that the roll clamp is in the short / long arm position and rotated so that the short arm is to the right. [Figure 5B] FIG. 5B shows the roll clamp of FIG. 4 with the swing cylinder positioned so that the roll clamp is in the short / long arm position and rotated so that the short arm is to the right. [Figure 6] FIG. 6 shows a side view of an improved swing roll clamp as described herein. [Figure 7] FIG. 7 shows a top view of the swing roll clamp of FIG. 6 with equal arm configuration. [Figure 8] FIG. 8 shows the effect of moving the arm pivot outward on the swing angle of the swing frame roll clamp. [Figure 9] FIG. 9 shows the effect of moving the arm pivot outward on the swing angle of the swing frame roll clamp. [Figure 10] FIG. 10 shows the position of the swing axis of the swing roll clamp of FIG. [Figure 11] FIG. 11 shows a top view of the swing roll clamp of FIG. 6 in a short / long arm configuration with the short arm on the left. [Figure 12] FIG. 12 shows a top view of the swing roll clamp of FIG. 6 in a short / long arm configuration, with the short arm on the right.

[0009] Detailed Description of the Preferred Embodiments

[0010]

[0019] Referring specifically to the drawings, and particularly to FIG. 1 , in which like parts are designated by like reference numerals, an exemplary swing frame roll clamp, generally designated 20, can be mounted on a fork lift truck 22, although the clamp can also be mounted on other types of vehicles. A faceplate 24 of the roll clamp 20 is attached to a rotor 26 that is attached to a carriage 28 of the lift truck. The carriage is positioned to move up and down within a lift truck mast 30 that can tilt fore and aft relative to the lift truck to vary the angular relationship of the clamp and / or engaging rolls relative to the surface supporting the lift truck.

[0011]

[0020] The rotor 26 generally includes a base plate 32 with a hook 34 attached to it that engages with a forklift carriage 28. The base plate 32 is attached to the outer ring of a bearing 36. Gear teeth formed inside the inner ring of the bearing 36 mesh with gear teeth on a pinion rotatable by a hydraulic motor 38. The rotor provides powered rotation of the roll clamp 20 about an axis of rotation 40 that is generally parallel to the longitudinal axis of the lift truck. Rotation of the clamp allows engagement and handling of a cylindrical roll 42 of paper or other material when the roll's central axis is oriented horizontally, as shown in FIG. 1, for loading the roll into a machine such as a printing press, or vertically for transport or stacking.

[0012]

[0021] 2 and 3, pivotally attached to the clamp's faceplate 24 by respective pivot pins 44 are a pair of subframes 46, 48 each having a flange 86, 88 distal from the center of the faceplate and a flange proximal to the center of faceplates 87, 89. Extension or retraction of a hydraulic swing frame ram 50, which is pivotally connected at one end to the faceplate 24 by a pin 52 and at the other end to a swing arm bracket 54 by a second pin 56, pivots the subframe relative to the faceplate 24 about an axis extending transverse to the clamp's axis of rotation 40. The swing ram bracket 54 is rigidly secured to the subframes 46, 48 by a pin 60 that pivotally secures a shorter clamp arm 62 to the subframe and a pin 64 that secures a short arm clamp ram 66 to the subframe. The longer clamp arm 68 is also pivotally connected to the subframes 46, 48 by pivot pins 70 and is pivoted relative to the subframes by a plurality of hydraulic long arm clamp rams 72 connected to the subframe by pins 74 and to the long clamp arm by pins 76. Clamp pads 79 are pivotally mounted to the distal ends of the long clamp arm 68 and the short clamp arm 62 and are positioned to engage the roll of paper or other material 42 when the long arm clamp ram 72 and the short arm clamp ram 66 are extended, causing the clamp arms to pivot toward each other.

[0013]

[0022] To enable gripping of cylindrical loads while resting horizontally or in a "bilge position," or adjacent to a wall or other obstacle, swing-frame roll clamp attachments such as those shown in FIGS. 1-3 are configured with a pair of opposing arms, one longer than the other. Thus, for example, when roll 42 is positioned with its axis in a horizontal plane, the roll clamp's upper (long) arm 68 preferably extends further forward of the lift vehicle than the lower (short) arm 62 so that the upper arm can overreach the roll and clamp pads 79 on the ends of the long and short clamp arms can engage the roll in diametrically opposed positions without the need to wed the lower arm under the roll. Similarly, when the roll is resting vertically adjacent to a wall, the long arm can overreach the side of the roll that is not adjacent to the wall and grip the roll in diametrically opposed positions without the need to wed the short arm between the roll and the wall.

[0014]

[0023] On the other hand, when rolls are transported or stacked with their longitudinal axes vertical, it may be preferable for the arms on both sides of the roll to extend equally forward of the lift vehicle to facilitate insertion between closely adjacent rolls without damage. Additionally, it is often useful to move the clamps or rolls laterally relative to their longitudinal axes to align them without moving the lift vehicle during stacking or loading or unloading of the transport vehicle, or to slightly change the height of a roll when placing horizontally oriented rolls in the machine. By extending or retracting the swinging frame ram 50, the forklift operator can pivot the subframes 46, 48 about their central connection to the faceplate 24 and (virtually) move the attached clamp arms 62, 68 between an unequal arm length position 80 and an equal arm length position 82.

[0015]

[0024] Figures 4, 5A, and 5B illustrate this capability. Referring to Figure 4, for example, a swing-frame roll clamp attachment 200 for a lift truck can be used to grip and move a cylindrical load 202 using a clamp arm assembly 204 pivotally mounted to a bracket 206 on a mounting plate 215. The clamp arm assembly 204 can include a long arm 208 and a short arm 210, each terminating in a clamp pad 212 shaped to firmly grip a cylindrical surface. A swing cylinder 214 is used to position the clamp arm assembly in either a long / short arm configuration relative to the load 202 or an equal arm configuration relative to the load. In Figure 4, for example, the swing cylinder 214 is extended so that the side of the clamp arm assembly 204 proximal to the short arm 210 is angled outward by a swing angle 218 relative to the mounting plate 215. In this position of the swing cylinder 214, the swing frame roll clamp attachment 200 is in an equal arm configuration suitable for gripping a cylindrical roll that is vertically stationary adjacent to another cylindrical roll, where overreach is not required or is impractical to achieve due to barriers on either side of the load.

[0016]

[0025] 5A shows swing frame roll clamp attachment 200 in a reverse short / long arm configuration, where swing cylinder 214 is retracted so that the side of clamp arm assembly 204 adjacent short arm 208 abuts mounting plate 215, while the side of clamp arm assembly 204 adjacent long arm 210 is angled outward relative to mounting plate 215 by swing angle 220. In this short / long arm configuration, swing frame roll clamp attachment 200 can overreach roll 202 to securely grip it, even if it is adjacent a wall or other obstacle. FIG. 5B similarly shows the swing frame attachment in a short / long arm configuration, but with rotor 216 positioning short arm 210 to the left of long arm 208.

[0017]

[0026] Thus, the swing-frame roll clamp attachment 200 shown in Figures 4, 5A, and 5B facilitates grasping of cylindrical loads, such as rolls, regardless of anticipated obstacles such as walls, floors, or adjacent rolls, and allows for direct insertion or withdrawal of the clamp. Direct insertion / removal occurs when the vehicle to which the clamp is attached does not need to change angle to deposit the load or back up after depositing the load. This flexibility is achieved by alternating between equal-arm and short / long-arm configurations. The former is achieved by positioning the clamp fully on the long-arm side (swinging), and the latter is achieved by positioning the clamp fully on the short-arm side (swinging).

[0018]

[0027] In many cases, the lift truck operator can predict which side of the clamp the short arm will need to occupy and pre-orient the clamp for optimal clamp placement and subsequent load / unloading. When the proper clamp orientation cannot be predicted, the proper orientation must be determined upon arrival at the destination, and the clamp often requires a 180-degree rotation if the current orientation is opposite to the required orientation. Examples of unpredictable clamp orientation include traditional situations where a human directly operates the lift truck or when automated lift trucks are utilized in the process. However, in many cases, there is not enough maneuverability next to the load to allow the clamp arm to rotate to the desired position. This means the lift truck must be moved to an area with sufficient space, rotate the clamp arm 180 degrees around an axis perpendicular to the axis along which the clamp arm swings, and then re-approach the load in the desired position.

[0019]

[0028] An improved swinging frame roll clamp is provided that eliminates the need to rotate the clamp arm when the short arm approaches a load in the wrong orientation. In some embodiments, this feature also allows for the elimination of a rotating body, which significantly reduces the weight of the attachment. In some embodiments, the pivot point of the swinging arm assembly can be moved farther from the mounting plate than exists in current swinging frame roll clamps. In such embodiments, the improved swinging frame roll clamp allows for the handling of loads having larger diameters than can be accurately positioned with existing swinging frame roll clamps.

[0020]

[0029] 6 and 7 illustrate an improved swing-frame roll clamp 300 selectively attachable to a lift truck 302 having a mast 304 used to lift, transport, and lower a load gripped by the roll clamp 300. The roll clamp 300 preferably includes a clamp arm assembly 306 pivotally mounted to a bracket 308, which is in turn secured to a mounting plate 310 that can attach the roll clamp 300 to the lift truck 302. The clamp arm assembly 306 preferably does not include a short arm and a long arm. Rather, the clamp arm assembly 306 includes opposing arms 316 and 318 of equal length, each having a clamp pad 320 attached to its end, and each arm is manipulated during opening and closing movements via a clamp cylinder 322. The clamp arms 316, 318 are configured to swing about a swing axis through a pivot point on the bracket 308.

[0021]

[0030] Thus, unlike swing frame roll clamp attachment 200 of FIG. 4, swing frame roll clamp attachment 300 has an equal-arm configuration in its neutral position, where the angles of the clamp arms relative to mounting plate 310 are the same. Conversely, the short / long arm configuration is achieved either by fully retracting swing actuator 312 from its neutral position, in which case arm 316 becomes a short arm and arm 318 becomes a long arm, or by extending swing actuator 312 from its neutral position until arm 318 contacts member 319, in which case arm 316 becomes a long arm and arm 318 becomes a short arm. In other words, the arms are designed to be equal when facing forward, rather than long and short when fully swung to one side and equal when fully swung to the other side. In this design, the long and short configurations are accessible when fully swung to either side, and operation of swing actuator 312 determines which arm is the short arm and which arm is the long arm. This design eliminates the need for a rotator in applications where the roll is not intended to be lifted from, carried into, or lowered to a bilge location. However, in some embodiments, a rotator can be included when it is desirable to pick up, carry, or deposit cargo at the bilge location. Those skilled in the art will appreciate that the swing actuator 312 will typically include a hydraulic cylinder, but will also appreciate that other actuators, such as electric actuators, can be used.

[0022]

[0031] Additionally, in some embodiments, swing frame roll clamps can position the pivot point of the swing arm assembly farther from the mounting plate than is present in current swing frame roll clamps. As noted above, with equal arm orientations in the neutral position of the swing cylinder 312, the effective "swing angle" is cut in half. Half the angle is used when swinging to the right, and half is used when swinging to the left. To achieve the same long-arm and short-arm configuration as prior art swing frame roll clamps, the swing angle must be increased. To achieve this increased swing angle, the pivot point of the swing frame roll clamp attachment is moved forward. This increases the available swing range by pivoting further away from the mounting plate. This can be seen by comparing Figures 8 and 9. In Figure 8, the pivot axis is relatively close to the mounting plate, so spacing 315 is small and does not allow for large angular deflections of the clamp arm. However, in Figure 9, the pivot axis is moved farther from the mounting plate, and spacing 314 allows for greater deflection. 10 and 11 show that the effect of moving the pivot axis defined by flange 308 outward is to significantly increase the swing angle of clamp arms 316 and 318.

[0023]

[0032] However, in other embodiments, the swing angle of clamp attachment 300 can be increased by including two swing cylinders 312, one attached to each of arms 316 and 318, which are adjusted by hydraulically connecting the head end of one swing cylinder to the rod end of the other swing cylinder. In this design, when pressure is applied to the swing cylinders, one pushes and the other pulls.

[0024]

[0033] As described above, the improved swinging frame clamp attachment 300 eliminates the need for clamp rotation / reorientation and the load required to accommodate a barrier adjacent to the load to be gripped / deposited. Eliminating the need for rotation, in turn, allows for a reduction in the attachment's weight by eliminating the rotor, one of the heavier components of a swinging frame roll clamp. Eliminating rotation also reduces the time per operation. Moving the swinging pivot forward increases the available swing angle of the disclosed swinging frame roll clamp attachment. This design also allows the clamp to install rolls of a larger diameter range directly against a wall or boundary using a direct insertion / extraction method. For example, the swinging frame roll clamp 300 disclosed in FIGS. 6-11 may install a roll directly against a wall, or against another roll as shown in FIG. 12. However, the swinging frame roll clamp 200 shown in FIGS. 4, 5A, and 5B requires a 41 mm gap between the roll and the boundary when stacking or gripping rolls of the same diameter.

[0025]

[0034] It is understood that the invention claimed herein is not limited to the particular embodiments described, but rather that variations may be made without departing from the scope of the invention as defined in the appended claims, as interpreted in accordance with current legal principles, including the doctrine of equivalents or any other principle that expands the enforceable scope of the claims beyond their literal scope. The incorporation by reference of the above documents is limited so that no subject matter contrary to the explicit disclosure herein is incorporated. The incorporation by reference of the above documents is further limited so that claims contained in the documents are not incorporated herein by reference. The incorporation by reference of the above documents is further limited so that any definitions provided therein are not incorporated herein by reference unless expressly included herein. In the event of a conflict between the usages in this document and those of the documents so incorporated by reference, the usage of the incorporated references should be considered supplementary to the usage in this document. In the event of an incompatible conflict, the usage in this document controls. Unless the context dictates otherwise, a reference in a claim to the number of instances of an element, whether a reference to one instance or to more than one instance, requires at least the recited number of instances of the element, but is not intended to exclude from the scope of the claim structures or methods having more instances of that element than recited. The term "comprises" or its derivatives, when used in the claims, is used in a non-exclusive sense that is not intended to exclude the presence of other elements or steps in the claimed structure or method.

Claims

1. A swinging frame roll clamp includes a mounting plate mountable to a lift truck and a pair of opposing clamp arms configured to selectively and alternately grip and release a cylindrical load, each opposing clamp arm being capable of being either a short arm or a long arm relative to the other opposing clamp arm.

2. 10. The swing frame roll clamp attachment of claim 1, wherein each opposing clamp arm is either a short arm or a long arm based on operation of a swing actuator between a fully retracted position and a fully extended position.

3. 3. The swing frame roll clamp of claim 2, wherein at least one of the fully extended and fully retracted positions is defined by contact between a respective clamp arm and a stop member.

4. 3. The swing frame roll clamp of claim 2, wherein the swing actuator is capable of being configured for equal arm configurations in relation to positions between the fully extended position and the fully retracted position.

5. 2. The swing frame roll clamp of claim 1, wherein the swing frame roll clamp does not include a rotor that swings about a swing axis and rotates the clamp arm about an axis perpendicular to the swing axis.

6. 1. A swing frame roll clamp comprising: a mounting plate mountable to a lift truck; and a pair of opposing clamp arms configured to selectively and alternately grip and release cylindrical loads, the opposing clamp arms configured to swing relative to the mounting plate between a fully retracted position and a fully extended position via operation of a swing actuator, each of the fully retracted and fully extended positions comprising a short / long arm configuration of the swing frame roll clamp.

7. 2. The swing frame roll clamp of claim 1, wherein at least one of the fully extended and fully retracted positions is defined by contact between a respective clamp arm and a stop member.

8. 10. The swing frame roll clamp of claim 1, wherein the swing actuator is capable of being configured in equal arm configurations in relation to positions between the fully extended position and the fully retracted position.

9. 2. The swing frame roll clamp of claim 1, wherein the swing frame roll clamp does not include a rotor that swings about a swing axis and rotates the clamp arm about an axis perpendicular to the swing axis.

10. 1. A swing frame roll clamp attachment comprising: a mounting plate mountable to a lift truck; and a pair of opposing clamp arms swingable about a first axis and configured to selectively and alternately grip and release cylindrical loads, the roll clamp attachment having a short arm on one side of the first axis and configurable to prevent the short arm from rotating about an axis perpendicular to the first axis.

11. 11. The swing frame roll clamp of claim 10, wherein each opposing clamp arm can be either a short arm or a long arm relative to the other opposing clamp arm.

12. 12. The swing frame roll clamp attachment of claim 11, wherein each opposing clamp arm is either a short arm or a long arm based on movement of the swing actuator between a fully retracted position and a fully extended position.

13. 13. The swing frame roll clamp of claim 12, wherein at least one of the fully extended and fully retracted positions is defined by contact between a respective clamp arm and a stop member.

14. 13. The swing frame roll clamp of claim 12, wherein the swing actuator is configurable to equal arm configurations in relation to positions between the fully extended position and the fully retracted position.

15. 11. The swing frame roll clamp of claim 10, which does not include a rotor that rotates the clamp arm about the axis perpendicular to the first axis.

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