US 3730368 A
Apparatus for lifting rolls of material comprising a probe with expansible jaws for engaging the center of a roll of material or any other object having a hollow core in combination with a flood light for illuminating the flat top of a roll of material. A photo cell positioned in the tip of the probe senses the lack of reflected light from the roll when positioned directly over the hole and triggers a relay which sounds a horn, lights a light or otherwise makes known to the operator that the probe is in position to be lowered into the hole.
Description (OCR text may contain errors)
United States Patent [191 Dalglish May 1, 1973 LIGHT GUIDED CENTER LIFT H er ran s. l ls i 2 Cherokee Avenue, St. Paul, Minn. 551 17 Filed: Jan. 6, 1972 Appl. N0.: 215,754
US. Cl ..2l4/653, 214/658, 214/D1G. 4 Int. Cl ..B66c 1/54 Field of Search ..2l4/653, 658, 651, 214/674, DIG. 1, DIG. 3, DIG. 4, 620, 750,
References Cited UNITED STATES PATENTS 3,134,620 5/1964 Blaisdell ..2l4/658 X FOREIGN PATENTS OR APPLICATIONS 710,434 5/1965 Canada ..2l4/l BC V lllllll.
Primary Examiner-Robert G. Sheridan Assistant Examiner-George F. Abraham AttorneyRobert M. Dunning 5 7 ABSTRACT Apparatus for lifting rolls of material comprising a probe with expansible jaws for engaging the center of a roll of material or any other object having a hollow core in combination with a flood light for illuminating the flat top of a roll of material. A photo cell positioned in the tip of the probe senses the lack of reflected light from the roll when positioned directly over the hole and triggers a relay which sounds a horn, lights a light or otherwise makes known to the operator that the probe is in position to be lowered into the hole.
10 Claims, 3 Drawing Figures LIGHT GUIDED CENTER LIFT BACKGROUND OF THE INVENTION In the prior art the handling of rolls of material, such as paper, plastic, foil, or coils of wire or cable, etc., has resulted in a high incidence of damage to the material on the roll. To avoid this the rolls have been handled and moved by an expansible probe which is inserted into the hollow center of the roll, reel or the like. Such a probe is a subject of my issued US. Pat. No. 3,423,120 entitled CENTER LIFT." This probe is provided with a set of expansible jaws so that it can be inserted into the center of the roll of material and engage the inner walls thereof Since the rolls are too heavy to be manually moved about, this probe works best in conjunction with an industrial truck which can be used to carry the probe up to the roll and insert it therein. However, when the probe is mounted on the front of the truck the lifting apparatus on the truck blocks the vision of the operator so that it is difficult to properly align the probe with the hole in the center of the roll of material. Because of this, time can'be lost searching for the correct engagement position and furthermore damage to the roll is possible if the truck is repeatedly bumped into the roll while searching for the hole. The present invention provides apparatus to overcome this difficulty. The device may similarly be used on a crane or walking crane where stacked rolls above eye level necessitates searching for the center hole.
SUMMARY OF THE INVENTION Briefly, my invention contemplates mounting a probe on a boom which is vertically pivotally mounted von brackets on the front of an industrial truck, crane or other lifting device. Also mounted on said brackets, as those on which the boom is mounted, is an hydraulically actuated arcuate back plate which can be moved out by an hydraulic cylinder so as to engage the outside edge of a roll of material as the truck or other mobile means approaches the said roll to pick it up. Said arcuate back plate acts as a centering force by engaging the roll at two spaced points so as to pivot the boom thus centering the probe radially over the roll of material. As a result the boom on which the lifting probe is supported will always extend directly toward the center of the roll.
The present invention also contemplates providing a floodlight which is mounted on the boom and is directed to illuminate the top of a roll of material in the area below the tip of the probe as it is progressing over the roll. The floodlight is turned on only after the probe tip is progressing over the top of the roll. The reflected light from the top of the roll is sensed or received by a small photo cell which is mounted in the hollow tip of the lifting probe. The signal from the photo cell maintains a relay in an off position as long as reflected light is perceived by the photo cell. However, when the probe moves over the center hole in the roll of material the photo cell receives no reflected light and this lack of light signals through a relay to actuate a horn, light a light or actuate other signaling means to tell the operator that the probe is properly aligned over the hole in the roll. Upon receiving this signal, the operator may then lower the vertical mast mechanism to lower the probe into the hole and thereby to engage the roll. As can be seen this signal permits the lifting of rolls of material where the operator cannot visually center the probe over the hole.
Occasionally it has been found when lifting large rolls of material that certain layers of material within a roll of material tend to be loosely wound for various reasons causing a lack of frictional contact between layers. For instance, in rolls of plastic the center or inner layers of material in the roll tend to trap air between the individual layers as the roll is being wound thus negating the frictional holding of the said inner layers of material and thus creating a possibility of the telescoping of the roll when attempting to lift the roll with a center probe. The present invention anticipates this situation by providing an arcuate back plate which is concave or otherwise formed so as to match the curvature of the outside of the roll. When the probe has been inserted into the center of the roll the back plate cylinder is then actuated to clamp the roll between the center probe and the back plate thus stabilizing the roll against telescoping.
The proper sequence of operation must be maintained in order that the combination just described will function properly and permit the lifting and moving of rolls of material with a minimum of damage to the roll resulting in a loss of material.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of my light guided center lift mounted upon an industrial lift truck and in position to be lowered into a roll of material having a hollow central aperture.
FIG. 2 is a side elevational view, partly in section, showing the center lift, the supporting boom, and the clamping and centering plate construction.
FIG. 3 is a horizontal sectional view of the clamping plate actuating mechanism, the position of the section being indicated by the line 3-3 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT As indicated in FIG. 1 of the drawings, my roll lifting apparatus A is mounted upon a typical industrial truck B similar to that used in factories and loading yards for lifting and conveying materials of various sorts. Trucks of this type are provided with masts 10 which supports lift forks or the like. In the present construction, the mast 10 supports a pair of vertically spaced mounting members 11 and 12 movable vertically throughout the length of the mast. If desired, the mast may be of the telescoping type so that the mast will extend vertically or elongate vertically in order to lift the object to be lifted to greater heights.
The mounting members 11 and 12 are provided with a pivot plate 9 which supports forwardly projecting parallel lugs or ears l3 and 14 respectively. A vertical mounting plate 15 is provided with rearwardly extending ears l6 and 17 which rest upon the ears of lugs 13 and 14. A pivot shaft 19 extends through the adjacent ears 13, 16 and I4, 17 to pivotally support the mounting plate with respect to the vertically movable mounting members 11 and 12.
A boom 20 is secured to the mounting plate 15 to extend forwardly from the upper end thereof. The boom 20 supports a downwardly projecting probe 21. The probe 21, in general, is similar to that described in my above mentioned US. Pat. No. 3,423,120. This probe includes a plurality of jaws which project outwardly from the probe and engage the walls of the central opening or core of the roll C. The roll C may be of any suitable material such as paper, plastic, foil or other sheet material, or can comprise spools of wire, cable or other such material. One of the main differences between the probe 21 and the probe shown in the patent lies in the fact that the tapered tip 26 of the probe is provided with an axial socket or recess 27 designed to accommodate a small photo cell 29. A flood light 30 is mounted upon the boom and positioned to direct light downwardly onto a surface beneath the probe 21 when the probe is raised slightly above such a surface. For example, when the probe is slightly above the surface of a roll C, the light 30 will direct its rays in a generally oval pattern indicated by the broken line 31 in FIG. 1 of the drawings.
A boom positioning and roll clamping plate 32 is supported by the mounting plate 15, and is movable toward and away from the surface of a roll engaged by the probe 21. The plate 32 is curved in transverse section either to fit the contour of the roll 22 or to provide a slightly lesser center of arcuation than the exterior of the roll C. The plate 32 and the mounting plate 15 are provided with pairs of parallel ears 33 and 34. Lever arms 35 and 36 are pivotally connected at 37 and 39 respectively to the ears 33 and 34. The levers 35 and 36 are centrally pivotally connected together as indicated at 40. Rollers 41 and 42 are pivotally supported at the lower ends of the levers 35 and 36, and these rollers are vertically slideable in slides 43 and 44 on the mounting plate 15 and on the plate 32 respectively.
A cylinder 45 is pivotally connected at 46 to a bracket 47 on the mounting plate 15. A roller 49 is mounted on the end of a piston rod 50 actuated by a piston within the cylinder 45. The roller 49 is engageable with a cam track 51 mounted upon the arm 36. Upon expansion of the cylinder, piston means the arms 35 and 36 are pivoted to the position indicated in FIG. 2, forcing the plate 32 toward the probe 21. Retraction of the piston rod 50 into the cylinder 45 acts to move the plate 32 in a direction away from the probe 21 and toward the mounting plate 15.
A generally triangular cam 52a having an inclined under surface 52 is supported by the mounting plate 15. As the arms 35 and 36 pivoted toward alignment in the collapsing of the plate 32 toward the mast, the
' roller 49a engages the cam surface 52, the rollers 44 and 49a engaging between the curved surface of the cam 51 and the cam surface 52. The cam surface 52 greatly increases the effective force ofthe piston rod 50 against the scissors-like arms when the arms 35, 36 are in nearly collapsed condition. By the time the arm 36 pivots upwardly sufficiently, the roller 49 is engaged within the curved cam surface of the cam 51 as indicated in FIG. 2. In other words, the cam surface 52 engages the roller 44a and forces the arm 36 away from the mounting plate 15, providing a greatly increased force tending to extend the scissor arms 35, 36 where such force is of greatest importance.
The circuit to the photo electric cell 29 includes a photo cell controller diagramatically illustrated at 53, a relay 54, and a horn 55. The circuit arrangement is such that the relay will actuate a circuit to the horn or other alarm only when the photo cell detects the absence of light. In other words, as along as the photo cell is receiving light which is reflected from the surface of the roll or other such member being lifted, the signal device is maintained in a non conducting or ofi position. However, when the probe passes over the hollow center of the roll or other object being lifted, no reflected light is detected and a signal is provided to the effect that the probe is directly over the center of the roll. It is only necessary that the probe be lowered into the hollow roll center. The roll is engaged by the probe and may be lifted and carried from one area to another.
In the preferred method of operation, the plate 32 is moved or extended into the position indicated in FIG. 2 of the drawings, and the truck is moved toward the roll. When the plate 32 engages the periphery of the roll, the curved nature of the plate causes the boom to be swung into a position extending radially inwardly from the roll edge, the center of the boom extending directly over the enter of the roll. The plate 32 is slowly retracted, and the truck B is moved forwardly, the reflected light from the light source 30 on the surface of the roll maintaining the relay 54 from energizing the horn or other alarm 55. When the probe end moves to a position over the center aperture of the reel, the photo electric cell fails to receive reflected light, and the relay is actuated, actuating the horn or other signal to show that the probe is in the proper location. The probe is then lowered with the boom and the probe is engaged in the roll. If desired, the plate 32 may be moved against the roll to clamp the area of the roll between the plate 32 and the probe 21. The roll may then be lifted and carried to a desired point.
As is indicated in FIG. 2 of the drawings, a cylinder 60 is pivotally secured as indicated at 61 between suitable supporting plates 62 near the end of the boom. A piston in the cylinder 60 (not illustrated) is connected to a piston rod 63 provided with a clevis 64 pivotally connected as indicated at 65 to an ear 66 on the plate 69. The piston in the cylinder 60 is usually free to slide, permitting the alignment of the boom relative to the roll. However, the piston rod may be actuated to pivot the boom about the axis 19 when it is so desired.
It should be understood that a number of variations and modifications may be made to the apparatus disclosed without departing from the spirit and scope of the invention. For example, the particular scissors arrangement utilized to move clamp 32 in and out is only one of a number of possible approaches that could be used for actuating clamp 32. Other structural variations include different types of pivoting mounts for the probe, boom, and clamp assembly. The particular circuit arrangement shown is examplary only and should not be construed as limiting the invention. Other types of signaling arrangements could be used to indicate when the tip of the probe is directly over the hole and the relay horn arrangement shown in the present invention is only one of many possibilities. The position of floodlight 30 is not critical at all to the operation of the invention. It has been found that the light can equally well be mounted exterior to the housing of the probe 21. Considering all of these variations the following claims are presented with the intention of covering only the patentable concepts herein.
1. Apparatus for handling rolls of material comprismg:
a center lift probe having a means for engaging the inside of the hollow center of the roll of material, said probe being carried on a boom means which is adapted to be lifted and lowered by a movable lifting means;
radiant energy projecting means on said boom means and positioned to illuminate an area beneath said probe;
radiant energy detecting means in said probe operable to detect and signal the absence of reflected radiant energy.
2. The apparatus of claim 1 and in which said boom means is pivotally mounted with respect to said mova ble lifting means for pivoting movement about a generally vertical axis.
3. The apparatus of claim 1 including a clamp means extendably mounted on said boom means and operable to engage the side of said rolls of material when said probe is engaging the center cores of said rolls.
4. The apparatus of claim 3 in which said detecting means comprises a light detector in the tip of said probe connected to provide a signal when no reflected light is detected thereby.
5. The apparatus of claim 3 in which said clamp means comprises a concave plate mounted to said boom plate by a pair of scissors extenders which are actuated hydraulically.
6. The apparatus of claim 4 in which said clamp means comprises a concave plate mounted to said boom plate by a pair of scissors extenders which are actuated hydraulically.
7. The apparatus of claim 6 in which said boom means is pivotally mounted with respect to said movable lifting means for pivoting movement about a generally vertical axis.
8. The apparatus of claim 7 in which said projecting means comprises a floodlight mounted on said boom means.
9. The apparatus of claim 8 in which said light detector controls said signal through an electrical relay.