US3420565A

US3420565A - Roll clamp for lift truck and method

Info

Publication number: US3420565A
Application number: US615259A
Authority: US
Inventors: Robert L Messinger
Original assignee: Eaton Yale and Towne Inc
Current assignee: Yale Materials Handling Corp
Priority date: 1967-02-10
Filing date: 1967-02-10
Publication date: 1969-01-07
Anticipated expiration: 1986-01-07

Description

Jan- 7, 1969 R. l.. MESSINGER ROLL CLAMP FOR LIFT TRUCK AND METHOD Filed Feb. 1o, 1967 Sheet INVNTOR. M55/N65? u* l y fx y R. L.. MESSINGER ROLL CLAMP FOR LIFT TRUCK AND METHOD Jan. 7, 1969 Sheet 2 of2 Filed Feb. l0. 1967 I N VENTOR. /Qof/er l. /Wfss/fveff? roA/fys United States Patent O 3,420,565 ROLL CLAMP FOR LIFT TRUCK AND METHOD Robert L. Messinger, Langhorne, Pa., assignor to Eaton Yale & Towne Inc., Cleveland, Ohio, a corporation of Ohio Filed Feb. 10, 1967, Ser. No. 615,259 U.S. Cl. 294-86 Int. Cl. B66f 9/18; B66c l/10 9 Claims ABSTRACT OF THE DISCLOSURE A roll clamp having linearly movable arms. One f the 'arms is pivoted and can be positively locked in either of two positions for manipulating rolls as by pushing, as well as for lifting rolls of different diameters.

The problem In the lifting and handling of large rolls of sheet material, as for example rolls of paper and the like, it is often desirable to push or otherwise manipulate a roll, as ywell 'as to grasp it for lifting purposes. Thus, a roll is grasped, lifted and moved; and, then it is pushed firmly into a confined space for most efficient storage.

Knowledge of the pertinent prior art indicates that while the clamping anms and jaws of roll clamping apparatus for industrial lift trucks have been movable for grasping and lifting purposes, they have not been capable of being positively locked in p-lace for pushing and like manipulation purposes.

Also, knowledge of the prior art indicates that the width of the clamp exceeds the normal width of the body of the truck to which it is attached. This is 'a su-bstantial hindrance to the flexibility of the truck, because it limits the trucks ability to get into and out of tight places to pick up and place a roll.

It is, therefore, obvious that a substantial advance to the art would 'be provided by a novel roll clamp for an industrial lift truck, wherein the pivoted arm could be locked in positions for manipulating rolls, so that it would have much greater ilexibility of use than simply grasping and lifting.

It is also evident that a substantial advance to the art would be provided by a novel roll clamp wherein the clamping arms are movable by hydraulic rams and further that movement and locking of the linearly and pivotally movable arm is effected automatically and simultaneously upon actuation of its hydraulic ram.

It is also evident that a substantial advance to the art would be provided by a novel roll clamp wherein the width of the clamping arms is maintained within the normal width of the body of the lift truck.

Objects of the invention are, therefore, to provide a novel r-oll clamp for an industrial lift truck embodying the foregoing features.

Of course, in addition to the foregoing, it is desirable for `an industrial lift truck roll clamp of the class herein contemplated, to be able to handle a wide range of diameters of rolls. This is also accomplished by the present invention by adapting both of the arms for linear movement toward and' away 4from one another; and, further by adapting one of the clamping arms for pivotal movement relative to the other arm. By this arrangement, a wide range of roll sizes. is accommodated by a relatively Vice short linear movement of either of the arms. This provides a very compact and sturdy structure and makes possible the use of relatively short and, thus, strong hydraulic actuating rams for moving the grasping arms.

Another Ifeat-ure of the invention that will become evident as this description progresses is that the roll clamp is adapted to pick up rolls lying horizontally. Thus, the linearly and pivotally movable arm is made of greater length than the short anm which is linearly movable only, so that it can reach over a roll lying horizontally. Thus, the shorter, linearly movable arm is positioned beneath the roll at a point near its contact with the floor; and, the longer arm contacts the top of the roll at a point substantially diametrically opposite the lower contact point. This steadies the roll and effectively holds it within t'he arms to grasp the roll for pick up.

As regards picking up a roll that is standing on end, the operator of the truck merely jockeys the ends of the arms into correct position and moves them together in a grasping fashion to hold the roll for movement.

A further feature of the invention that will become evident as the description progresses is that the clamp is rotatable about a horizontal axis. Thus, rolls may be gripped while standing on end and then rotated to be laid down, or may be rotated and thereby turned end for end. Further, rolls may be gripped while lying down on their side and then turned 90 to be stood on end, or rotated 180 and thus turned end for end. Thus, a roll can be gripped and picked up from substantially any position and also placed in substantially any position.

A still further feature of the invention is that each clamping arm is provided at the free end with a pivotally movable gripping jaw that automatically embraces the surface of a roll in an improved, grasping fashion.

I have thus outlined the general nature of my invention and its relation to the prior art in order that the description thereof that follows may be better understood, and in order that my contributions to the art may be better appreciated. There are, of course, additional features of my invention that will be described hereinafter and which will form the subject lmatter of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which my disclosure is based may be readily utilized as the basis for the designing of other structures for carrying out the several purposes of the invention. It is important, therefore, that the claims granted to me sh'all be construed suiciently broadly 'to prevent the appropriation of my invention by others skilled in the art.

Referring now to the drawings:

FIGURE l is a front-elevational view of the entire clamping mechanism of invention with the jaws positioned horizontally and for vertical spread; and

FIGURE 2 is a side-elevational view of FIGURE 1.

Referring now to the drawings, the reference numeral 10 represents the roll clamp of the present invention. A hanger block 12, shown at the left side of FIGURE 2', an angle mount'14 and a lower clip 16 make up part of the standard mechanism of the lift truck, not shown, for attaching the invention to the front end of the truck. These elements form no part of the present invention, and therefore, are shown and described only generally. The attachmet mechanism also includes a rotating mechanism, indicated generally by the reference numeral 18. This includes a horizontally oriented pivot shaft 20 upon which the invention is mounted for rotation at the will of the operator through the control and power provided by the rotating mechanism 18.

It will be understood, therefore, that the invention is adapted to be pivotally mounted on the lift truck and, if desired, may be lifted and lowered by mechanism carried by the truck, such as hydraulic lift rams.

Additionally, however, as will become evident, the

jaw carrying arms

22 and 24 can be moved toward and away from one another for grasping and manipulating purposes by their own control arms.

The roll clamp includes a frame comprising a rotatable front plate 26 supported by the rotatable pivot shaft 20, FIGURE 2. A body subassembly 28 is secured to the -rotatable front plate 26 by means of cross plates 30, FIGURES l and 2. As best shown in FIGURE l, the body subassembly 28 includes a rst pair of lineal guideways 32 on which are slidable a first pair of complementary guideways 34 which in turn support the lower or short gripper arm 22.

The body subassembly 28 also includes a second pair of guideways 36 on which is slidable a pair of complementary guideways 38 which in turn support the upper or longer gripper arm 24 of the roll clamp of invention.

A rst hydraulic rarn 40 is employed to manipulate the gripper arm 22 and a second hydraulic ram 42 is employed to manipulate the longer gripper arm 24. The first ram 40 has the cylinder head end 44 fastened to the upper cross plate by bolting at 46. The exposed end of the piston rod 48 is connected to the central portion of the arm assembly 22 by bolting at 50.

The second ram 42 has the cylinder head end 52 fastened to the lower cross plate 30 by bolting at 54. The exposed end of the piston rod 56 is connected to the central portion of the arm assembly 24 by bolting at 58.

By application of pressurized hydraulic fluid from hydraulic circuit means, not shown, the

gripper arms

22 and 24 can thereby be moved linearly relative to one another for grasping and manipulating purposes in a particular manner that will become evident as this description progresses.

The lower or shorter clamping arm 22, in detail As best shown in FIGURE 2 the clamping arm assembly 22 includes an L-shaped support plate 60 that is welded at upper and lower points 62 to each of the first complementary guideways 24. The piston rod 48 of ram is secured to a connecting plate assembly 64 and thus to the central portion of the L-shaped support plate 60. The L-shaped support plate includes a vertical plate portion 66 that is formed integrally with a horizontal plate portion 68. An arcuate or curved clamping plate 70 has the upper edge welded at 62 to the upper edge of the vertical plate portion 66. The lower, outer edge 72 of plate 70 is welded at 74 to the outer end of the horizontal plate portion 68. This provides a compact, stiff and strong, generally triangular Weldment.

Vertical movement of the clamping arm assembly 22 between the solid line position and the dotted line position by means of the first ram 40 is indicated in FIGURE 2. It is to be noted that it can be dropped below floor line, if desired. This will take place when the unit is pivoted for spreading the arms to grasp a larger roll.

At the outer end of the horizontal plate portion 68, there is a pivoted jaw 78. Each of the plates 68 and the jaw 78 has aligned pivot sleeves 80, attached by welding, and a pivot pin 82 is passed through and secured as by an appropriate cross pin or set screw, not shown.

The jaw 78 is automatically pivoted to a desired gripping orientation by contact with a roll, and is returned to a neutral position by means of a control spring 84. A yoke 86 is fastened to a median portion of the horizontal plate portion 68 and has a hole 88 through which the back hook end Vof the spring 84 is passed. The forward end of spring S4 has a loop end 90 and receives the back hook end 92 of a connecting rod 94. The forward end of the connecting rod 94 is pivotally connected at 96 to the underneath side of the lower jaw 78.

The upper or longer clamping arm 24, in detail As also shown more clearly in FIGURE 2, the clamping arm assembly 24 includes an arm carrier Weldment 4 98. Weldment 98 includes spaced plate means 100, also shown in FIGURE 2, bridged by an upper spacer plate 102 and a lower spacer plate 104 which provide a rigid box-like structure. By means of a vertical cross plate 106, best shown in FIGURE 2, the upper spacer plate 102 and the spacer plate 104, the carrier Weldment 98 is fastened to the second complementary guideways 38, FIGURE l, for linear movement thereon.

The piston rod 56 of ram 42 is secured to a cross plate 108, FIGURE 2 and thus to the central portion of the carrier Weldment 98.

The swinging arm assembly 24 comprises a swinging arm Weldment 110 that includes spaced arms 112, fabricated from plate stock, that are pivotally mounted to the arm carrier Weldment 98 by cross shaft 114. The cross shaft 114 is supported in the spaced plate means 100 by appropriate, aligned holes therein; and, the spaced arms 112 also each includes a hole to receive the shaft 114. A washer 116 and a suitable retainer cross pin at each end completes the assembly.

Extending between each of the spaced arms 112, to complete the Weldment 110, is an outer plate 118 and an inner plaie 120, welded in place for purposes of stiffening the spaced arms as a box-like Weldment. The outer plate 118 extends out beyond the inner plate 120 as best shown in FIGURE 2.

Vertical movement of the clamping arm assembly 24 between the solid line position and the dotted line position by means of the second hydraulic ram 42 is indicated in FIGURE 2. The particular manner in which the simultaneous pivoting action is also accomplished will be made evident as the description continues.

At the outer end of the swinging arm Weldment 110, there is an upper pivoted jaw 79. Each of the outer plate 118 and the jaw 79 has aligned pivot sleeves 80, attached as by welding, and a pivot pin 82 is passed through and secured as by an appropriate cross pin or set screw, not shown.

The jaw 79 is automatically pivoted to a desired gripping orientation by contact with the surface of a roll, and is returned to a neutral position by means of a control spring 8S. A yoke 87 is fastened to a median portion of the upper plate 118 and has a hole 88 through which the back hook end of spring 8S is passed. The forward end of spring 8S has a hoop end 90 and receives the back hook end 92 of a connecting rod 95. The forward end of the connecting rod is pivotally connected at 96 to the underneath side of the upper jaw 79.

The pivoting mejzanism for the upper clamping arm 24, in detail As set forth in the introductory portion of this specification, it is a purpose of the invention to lock the upper or longer arm 24 in either of two positions so that the arm can be used to push and otherwise manipulate a roll of material. This is accomplished by the present invention in two ways:

(l) By latch and stop means at the top position; and,

(2) By cam means at the bottom position.

The latch and stop means As best shown in FIGURE 2, a latch arm 122 is pivotally mounted to each plate of the arm carrier weldment 98. For this purpose, as shown in FIGURE l, a pivot stub shaft 124 extends outwardly from each plate 100. Each latch arm 122, as shown in FIGURE 2, has the bottom end journaled on the pivot stub shaft 124.

The latch arm 122 includes a latch notch 126 at the top and the spaced arms 112 each carry a latch pin 128, which is located to fall into the notch 126 when the several parts swing to a position for such action to take place.

Each latch arm element 122 also includes a cam surface 130 whose function in cocking the latch 122 back to a retracted position so that the notch 126 clears the pin 128, will be brought out below.

A latch return spring 132 is effective to pull the latch arm 122 to a holding position when the latch is in `a position to be so moved. Each latch arm 122 has a spring hook plate 134, best shown in FIGURE l, with a hole 136 to receive the hook end of the latch return spring 132. At the other end, the spring 132 is hooked to a rod element 138, best shown in FIGURE 2, fastened to the arm carrier weldment 98.

Beneath the rear end of each of the spaced arms 112 of the swinging arm weldment 110, there is a stop block 140. The stop block 140 is fastened to the outside of each plate 160 in engageable alignment with an arm 112. Each stop block 140 carries a set screw 142 and lock nut 144 for adjusing the stop position of an arm 112.

The latch arm 122 holds the swinging arm weldment 110 against clockwise rotation in the upper solid line position. The adjustable set screw 142 of the stop block 140 holds the arm weldment 110 against counterclockwise rotation.

An arrangement of par's wherein the latch arm and Stop block provide opposite anti-rotation is to be encompassed within the scope of the invention.

Each of the spaced arms 112 also carries a cam roller follower 146 which is engageable with a cam track 148 now to be described. It will be explained that the swinging arm weldment 110 is moved vertically downwardly from the solid line position by the second hydraulic ram 42. As it is so moved, the cam surface 130 on the latch 122 is moved by an abutment and releases the latch arm from the latch pin 128; and, the cam track 148 produces the pivoting action indicated. Additionally, as distinguished from the prior art of present knowledge, the cam track 148 is effective to positively lock the upper arm 24 in the dotted line position for both positive manipulating as by pushing, and also for positive grasping for lifting purposes.

The cam track 148 is formed in a block of steel 150, fastened to the outside of the body subassembly 28. A steel block 150 and track 148 is provided at each side as shown in FIGURE l. Since the subassembly 28 is xed relaiive to the

movable arms

22 and 24, the cam track 148 is held fast.

It will be noted that the cam track comprises a straight or vertical portion 152 and a sharply cut-back portion 154. The cut-back portion 154 functions as the locking portion.

Operation of the invention; downward movement from the solid line position of FIGURE 2 to the dotted line position As the second hydraulic ram 42, FIGURE l, is called upon to move the upper arm 24 down from the solid line position of FIGURE 2, the ca m surface 130 of the latch arm 122 engages the upper, outer corner 156 of the steel cam block 150. This cocks the latch arm 122 forward and releases the latch notch 126 from the latch holding pin 12S. The arm 24 is then free to pivot. However, the arm 24 does not pivot at the instant of latch release because the cam roller 146 has entered the straight portion 152 of the cam track 148. This holds the arm in the same attitude as shown in solid outline in FIGURE 2. However, subsequently when the cam follower roller 146 enters the sharply cut-back portion 154 of the track 148, the arm 24 pivots downwardly to assume the attitude of the dotted line position shown in FIGURE 2. Simultaneously, the arm 24 is locked in this dotted line attitude by the cut-back portion 154.

Upward` movement of the upper arm 24 from the dotted line position of FIGURE 2 back tothe solid line position As the second hydraulic ram 42, FIGURE 1, is called upon to move the upper arm 24 upwardly from the dotted line position, a sequence of events takes place. First, the sharply cut-back cam surface 154 initially pivots the arm up to the attitude of the solid line position, causing engagement between the back of the cam and the stop block Set screw 142. However, it is not yet at the actual top solid line position shown. This initial pivoting releases the lower lock condition and places the latch pin 128 in locking attitude.

Subsequent linear movement of the arm 24 places the cam follower roller 146 in the straight track portion 152 and, as it continues to move up, the cam surface 130 of the latch 122 moves past the upper corner 156 of the cam block 150. The spring 132 causes the latch notch 126 to drop onto the latch pin 128. Thus, after unlocking and pivoting have taken place, followed by some linear movement, locking the arm 24 in the solid line attitude then takes place. However, the arm 24 is still not yet at the position shown in the solid line of FIGURE 2.

Subsequent linear movement of the second ram 42 is effective, however, to place the arm 24 back at the solid line position.

The sequence, therefore, comprises the following steps:

(l) Unlocking the arm by movement out of the cutback cam portion, and simultaneously pivoting the arm upwardly or outwardly as the case may be so that the bottom of the arm abuts the stop block;

(2) Linearly moving the arm, thereby permitting the cam portion of the latch to release the latch notch into engaging relationship with the latch pin; and,

(3) Then, linearly moving the arm to the end of its linear path to assume the solid line position shown.

SUMMARY An important advantage of the invention is that while the arms may be used to push a roll of material, the width of the clamp never exceeds the normal width of the body of the truck to which it is mounted.

A further important advantage of the invention is that the pivoted arm is positively locked in each of its two operating positions.

A further important advantage of the invention is that when the arm is moved from one to the other of its positions, or vice versa, it is automatically positively locked in the position to which moved and this takes place without attention on the part of the truck operator.

Thus, the contribution of the present invention to the art resides in the feature that the pivotal arm is always rigid and is always positively held in an active position for grasping as well as otherwise manipulating a roll; and, movement between positions is automatically contributed as the arm moves from one position to the other.

I believe that the considerable merits and the greater simplicity of my invention will now be understood and appreciated by those skilled in the art.

I claim:

1. In a roll clamp of the class described:

a frame having first linear guide means thereon,

a first grasping arm carried by said first linear guide means and means for linearly moving said first grasping arm along said first linear guide means,

second linear guide means on said frame,

an arm carrier, and means for linearly moving said arm carrier along said second linear guide means,

a second grasping arm pivotally mounted to said arm carrier and movable between rst and second pivoted positions upon movement of said carrier, and including lock means, cooperable with lock means on said arm carrier in the rst pivoted position,

cam means on said frame,

cam means on said second grasping arm engageable with said frame cam means upon movement of said arm carrier to move said second arm to said second pivoted position, said ca-m means including means to lock said second arm in said second pivoted position,

and means on said second arm lock means engageable with means on said frame, upon movement of said carrier, to release and lock said lock means.

2. The invention according to -claim 1 wherein said lock means holds said second arm against one of clockwise and counterclockwise pivoting movement,

and stop means on said carrier and engageable with said second arm, holding said second arm against the other of clockwise and counterclockwise pivoting movement.

3. The invention according to claim 1 including stop means on said arm carrier and engageable with said second grasping arm, and in combination with said rst lock mean-s, holding said second arm against pivoting movement.

4. The invention according to claim 1 wherein said lock means comprises lever means pivoted to one of said `arm and said arm carrier, and latch pin means on the other of said arm and said arm carrier,

said pivoted lever means including latch notch means receiving said lat-ch pin means in locking relation when the several parts swing to a position for such action to take place,

and means normally biasing said latch lever means toward said latch pin means.

5. The invention according to claim 4 wherein said last recited engageable Imeans on said second arm comprises a cam surface on said lever means and engageable with said frame cam means upon movement of said carrier.

6. The invention according to claim 1 wherein said cam means on said frame is one of cam track and cam follower means; and, said cam means on said second grasping arm is the other of a cam track and cam follower means.

7. The invention according to claim 6 wherein said cam means on said frame is a cam track means and wherein said cam means on said second arm is a cam follower means.

8 8. The invention according to claim 1 wherein each of said first and second grasping arms is provided with a pivoted grasping jaw, movable into conformed relation to the surface of a Iroll on contact, and means lnormally biasing said jaws to a neutral position.

9. In a roll clamp of the class described:

a frame having irst linear guide means thereon,

a first clamp arm carried by said first linear guide means and means for linearly moving said arm relative to said guide means,

second linear guide means on said frame, an arm car rier, and means for linearly moving said arm means along said second linear guide means, a second clamping arm pivotally mounted to said arm carrier and movable between first and second pivoted positions corresponding respectivey to positions for clamping large and small rolls of sheet material,

means for locking said second clamping arm in said first pivoted position against clockwise or counterclockwise movement,

means for moving said second clamping arm to said second pivoted position,

and second means for locking said second clamp arm in said second pivoted position against clockwise and counterclockwise pivoting movement.

References Cited UNITED STATES PATENTS 3,127,209 3/1964 Faust et al. 294-88 3,198,568 8/1965 Mindrurn 294-88 3,252,609 5/1966 'Ellis 294-88 ANDRES H. NIELSEN, Primary Examiner.

U.S. Cl. X.R. 214-653; 294-88