US2951725A

US2951725A - Material handling apparatus

Info

Publication number: US2951725A
Application number: US673301A
Authority: US
Inventors: Jean Robert R St
Original assignee: Worcester Automatic Machine Co
Current assignee: Worcester Automatic Machine Co
Priority date: 1957-07-22
Filing date: 1957-07-22
Publication date: 1960-09-06
Anticipated expiration: 1977-09-06

Description

Sept. 6, 1960 R. R. ST. JEAN MATERIAL HANDLING APPARATUS 2 Sheets-Sheet 1 Filed July 22, 1957 FIG. I.

ROBERT R. sz JEAN 1N VENTOR il wf? ATTORNEY p 6,.1960 R. R. ST. JEAN 2,951,725

MATERIAL HANDLING APPARATUS Filed July 22, 1957 2 Sheets-*Sheet 2 ROBERT R. 57. JEAN INVENTOR ATTORNEY United States Patent fiice 2,951,725 Patented Sept. 6, 1960 MATERIAL HANDLING APPARATUS Robert R. St. Jean, Auburn, Mass., assignor to Worcester Automatic Machine Company, Worcester, Mass, a corporation of Massachusetts Filed July 22, 1957, Ser. No. 673,301 9 Claims. (Cl. 294-97) This invention relates to material handling apparatus and more particularly to apparatus arranged to be used with a crane for grasping and lifting heavy coils of metal and the like.

In the past it has been accepted practice to move coils, bars and similar articlm from place to place within a mill by use of an overhead crane and a grapple suspended from the crane hook. The grasping arms of these grapples have been releasable from the mill floor by a man actuating a lever. When the operation involves the stacking of heavy coils of metal strip, for instance, it has been necessary for the floor man to climb up the stock of coils to release the uppermost coil from the grapple. The crane operator has had no control over the grapple operation. Not only has it been wasteful of manpower to be forced to provide both a crane operator and a floor man, but, more importantly, the floor mans activities have been very dangerous and time-consuming. Such slow actuation of the grapple has meant that the mill crane has been occupied with this one job for an unduly long period of time and has not been available for other uses. These and other difiiculties experienced with prior art devices have been obviated by the present invention in a novel manner.

It is therefore an outstanding object of the invention to provide a material handling apparatus adapted to be suspended from the hook of a crane and actuatable by the crane operator from operative to inoperative condition.

Another object of this invention is the provision of an article-grasping means for suspension from a single cable, complete control of the means being possible through manipulation of the cable.

A still further object of the instant invention is the provision of a grapple having grasping arms and a single upstanding vertical rod adapted to be suspended from a crane hook, complete control of expansion, contraction and locking of the grasping arms being possible by manipulation of the rod.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

The character of the invention, however, may be best understood by reference to certain of its structural forms,

as illustrated by the accompanying drawings in which:

Figure l is a perspective view of a material handling apparatus embodying the principles of the invention,

Figure 2 is a sectional view of a portion of the apparatus taken on the line II-II of Figure 1,

Figure 3 is a view of the apparatus taken on the line III-III of Figure 2, and

Figure 4 is an elevational view of a portion of a modification of the invention.

Referring first to Figure 1, wherein are best shown the general features of the invention, the material handling apparatus, designated generally by the reference numeral 10, is shown .in use with a coil 11 of thin metal strip.

The coil is shown in phantom style to permit a clear showing of the apparatus. The apparatus 10 consists generally of a head 12 to which are hingedly fastened

grasping legs

13 and 14. A suspension rod 15 extends through an aperture 16 in the head and is connected at its lower end to a block 17 which, in turn, is connected by

links

18, 19, 21 and 22 to the grasping arms.

The head 12 is generally square in plan view and is a plate of considerable thickness. The aperture 16 passes completely through the head, as is evident in Figure 2, and consists of a central circular bore 23 from which radiate five lateral passages 24 equally spaced about the bore. Each passage has parallel sides and terminates in a semi-cylindrical surface; a conical counterbore 25 is formed in the underside of the head concentric with each of the said semi-cylindrical surfaces. A stop member 26 is fastened to the underside of the head and consists of U-shaped

sections

27 and 28 extending in opposite directions from the head.

The grasping arm 13 comprises a leg 29 having an elongated lower portion 31 and a short upper portion 32 which extends at an angle of about to the lower portion. The upper end of the leg is fastened to a side of the head 12 for free pivotal motion relative thereto. Another leg 33 similar to the leg 29 is similarly fastened to the opposite side of the head. These two legs are joined at their lower ends by plates and the like, so that the grasping arm is a rigid unitary structure. The lower end of the arm 13 is provided with an outwardlyextending foot 34 having a flat. upper surface which is generally horizontal when the apparatus is in the open or extended condition shown in Figure 2 of the drawings. The lower surface of the foot is somewhat inclined to its upper surface. The grasping arm 14 is composed of two

legs

35 and 36 which are similar to the

legs

29 and 33, but having their upper portions inclined oppositely. They are pivotally fastened to opposite sides of the head and are joined to make the grasping arm a rigid unitary structure; a foot 37 extends outwardly from the lower end.

The link 18 is pivotally attached at one end to the intermediate portion of the lower portion 31 of the leg 29 and the

other links

19, 21 and 22 are similarly connected to the intermediate portions of their

respective legs

33, 36 and 35. The links extend downwardly and inwardly and the lower end of each link is pivotally attached to a generally cubical block 17. The block is provided with a central vertical bore 38 extending completely therethrough.

'The suspension rod 15 extends through the aperture 16 in the head 12 and the bore 38 in the block 17. It is formed with a reduced upper portion 39, a reduced lower portion 41 and an enlarged intermediate portion 42. A ring 43 is formed at the upper end and stop nuts 44 and 45 are threaded in place on the lower end. A stop collar 46 is rigidly fastened on the intermediate portion by means of a pin 47. The diameter of the intermediate portion 42 is slightly smaller than the diameter of the bore 23 forming part of the aperture 16 through the head. The diameter of the upper portion 39 is slightly smaller than the widths of each of the passages 24. Between the intermediate portion and the upper portion is a conical transition surface 48 adapted to fit snugly into the counterbore 25 formed on the'undersurface of the head concentric with the semi-cylindrical extremity of each passage. The diameter of the lower portion 41 is much less than that of the bore 38 in the block 17, in which bore it normally resides, so that the suspension rod is permitted considerable misalignment relative to the block. The relative lengths of the portions of the suspension rod will be described more fully in connection with the operation of the apparatus.

The operation of the apparatus will now be readily understood in view of the above description. Let it be supposed that the operation to be performed is the stacking of coils of thin metal strip in a Warehouse. The Warehouse is provided with a mill crane running on tracks in the upper part of the building and capable of longitudinal and transverse motion over the area of the mill; a cable hangs downwardly and is provided with a hook at its lower end. The crane operator rides in a cab and may raise and lower the hook. In other words, the crane operator can move the hook longitudinally, transversely and vertically within the mill; however, because of the flexible nature of the cable, it is impossible for him to control the angular aspect of the hook to the vertical. With the apparatus resting on the floor in somewhat the condition shown in Figure 2, the operator causes the crane hook to engage the ring. The suspension rod 15 is in lowered position and the grasping arms are close together; the upper portion 39 resides in a passage 24 and the conical transition surface 48 engages the counterbore 25. The crane operator actuates the winch to pull upwardly on the cable and he lifts the apparatus from the ground. The rod cannot move upwardly or laterally relative to the head because the counterbore 25 locks the rod in the passage. The grasping arms, therefore, remain in collapsed condition during the passage of the apparatus through the air. The apparatus is stopped over a coil 11 and is lowered until the lower ends of the grasping arms rest on the mill floor; the coil rests on a pair of parallel wooden blocks, so that its lower end is somewhat removed from the surface of the floor. By lowering the hook slightly, the crane operator lowers the suspension rod until the transition surface is clear of the counterbore 25; it is then possible for him to move the rodent of the passage 24 to the center of the bore 23. He does this by moving the crane properly in a horizontal plane. It is then possible for him to move the suspension rod vertically until the nuts 44 and 45 engage the lower surface of the block 17. Further upward movement of the suspension rod causes similar movement of the block. Now, the block 17 and the

links

18, 19, 21 and 22 act as a toggle and a small vertical movement with little force of the block causes large outward movement of the grasping arms with considerable force. During this outward movement of the grasping arms, the foot 34 and the foot. 37 are able to slide under the lower surface of the coil. Outward motion of the arms is terminated by the engagement of the lower portions of the legs with the inner surface of the coil. This also serves to center the apparatus in the coil if such be necessary. During the vertical movement of the suspension rod, the enlarged intermediate portion 42 rises until it resides within the bore 23; the rod cannot move laterally to enter any of the passages 24 because the portion 42 has a diameter larger than the width of the passage. Further Vertical movement of the crane hook will lift the coil; the greater the weight of the coil, the greater force available in the grasping arms to press outwardly and hold the coil.

The crane operator moves the crane in a horizontal plane until the coil overlies the desired spot for deposit. Let it be supposed that the coil is to be deposited on a stack of previously-deposited coils; a floor man places a pair of parallel separating blocks on the top of the stack. The crane operator lowers the hook, apparatus, and coil until the coil rests on the separating blocks coaxially of the other coils in the stack. The stop member 26 strikes the upper surface of the coil and, as the crane cable is further loosened, the suspension rod 15 continues downwardly under its own weight. This causes the enlarged intermediate portion of the rod to move downwardly out of the bore 23 of the aperture'f of the head; this means that the upper portion 39 of the rod is coextensive with aperture. With the suspension rod in lowered position, the block 17 and the links 18,

19, 21 and 22 move downwardly under their own weight and the grasping arms move inwardly, so that the apparatus is in collapsed condition. {The crane operator then manipulates the crane hook so that the suspension rod is moved laterally into one of the passages 24. He then raises the hook and thereby moves the rod upwardly until the conical transition surface 48 moves into the conical counterbore 25. Then, the apparatus may be lifted from the interior of the coil without moving the grasping arms outwardly. The fact that the counterbore 25 is conical and the bevel formed thereby on the lower edge of the passage does not extend to the mouth or entrance of the passage means that the suspension rod cannot be moved laterally out of the passage and that the apparatus is locked in collapsed position.

It can be seen, then, that with the present invention it is possible for a crane operator to engage and release articles without the help of a floor man; This results in a considerable saving in time consumed by this type of operation and removes the possibilityof injury to the floor worker.

In Figure 4 isshown a modified version of the invention intended for use in handling articles and materials by grasping the outside surfaces. Only the lower part of the apparatus is shown, since the upper part is exactly like the corresponding part of the version shown in Figure 1. In this case, however, the grasping

arms

113 and 114 have inwardly-directed feet 134 and 137.

Links

118 and 122 are pivotally connected to the low portions of the grasping

arms

113 and 114, respectively. The links extend inwardly and upwardly for pivotal attachment to a block 117. The block has passing there'- through a lower reduced portion 141 of a suspension

rod having nuts

144 and 145 threaded onto the lower end thereof below the block. The operation of this modification of the invention is very similar to that described above. In this case, however, the inoperative condition is when the grasping arms are most widely separated; with the links arranged as they are, this means that the block 7117 is in its low position. The suspention rod 115 is locked by the fact that the conical transition surface resides in the conical counterbore, both not shown. The article to be carried, for instance, a stack 111 of flat plates rests on the feet 134and 137 and contacted by the grasping arms 113 and 114-. In this operative position, the suspension rod 115 is free to move upwardly through the aperture in the head and the upward movement of theblock 117 causes the grasping arms to move inwardly to clamp the stack 111.

It .is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

The invention having been thus described, what is claimed as new and desired to secure by Letters Patent 1. A material handling apparatus comprising a head having a vertically-extending central aperture, grasping arms hingedly connected to the head in generally opposed relation and extending downwardly therefrom, a suspension rod extending through the said aperture and having an upper portion of small diameter and an intermediate portion of relatively large diameter, links pivotally connecting the lower end of the said rod to the said grasping arms, first means providing lost motion between the rod and links, the aperture in the head having a non-circular conformation and having a portion in which the intermediate large portion of the rod can reside, the aperture also having a smaller portion extending laterally of the large portion in which the upper portionof the rod can reside'but not the intermediate portion, the aperture operating when the upper portion of the rod is located .in the smaller. portion of. the aperture and in a low position in the head to lock the rod against upward movement relative to the head, and means associated with the smaller portion to prevent lateral movement of the rod when it is located therein.

2. A material handling apparatus comprising a head having a vertically-extending central aperture, grasping arms hingedly connected tothe head in generally opposed relation and extending downwardly therefrom, a suspension rod extending through the aperture and having an upper portion of small diameter as well as an intermediate portion of relatively large diameter, a block slidably mounted on the lower end of the rod, links pivotally connecting the block to the said grasping arms, the block providing lost motion between the rod and links, the aperture in the head having a non-circular conformation and having a large portion in which the intermediate portion of the rod can reside, the aperture also having a smaller portion extending laterally of the large portion in which the upper portion of the rod can reside but not the intermediate portion, the aperture operating when the upper portion of the rod is located in the smaller portion of the aperture and in a low position in the head to lock the rod against upward movement relative to the head, and means associated with the smaller portion to prevent lateral movement of the rod when it is located therein.

3. A material handling apparatus comprising a head having a vertically-extending central aperture, a stop member extending outwardly from the head, grasping arms hingedly connected to the head in generally opposed relation and extending downwardly therefrom, the arms having laterally-extending feet at their lower ends, a suspension rod extending through the aperture and having an upper portion of small diameter as well as an intermediate portion of relatively large diameter, a block slidably mounted on the lower end of the rod, links pivotally connecting the block to the said grasping arms, the block providing lost motion between the rod and links, the aperture in the head having a non-circular conformation and having a large portion in which the intermediate portion of the rod can reside, the aperture also having a smaller portion extending laterally of the large portion in which the upper portion of the rod can reside but not the intermediate portion, the aperture operating when the upper portion of the rod is located in the smaller portion of the aperture and in a low position in the head to lock the rod against upward movement relative to the head, and means associated with the smaller portion to prevent lateral movement of the rod when it is located therein.

4. A material handling apparatus comprising a head having a vertically-extending central aperture, grasping arms hingedly connected to the head in generally opposed relation and extending downwardly therefrom, a suspension rod extending through the aperture and having an upper portion of small diameter, an intermediate portion of relatively large diameter, and a lower portion of small diameter, a block mounted on the said lower portion of the rod for considerable sliding movement along the said lower portion, links pivotally connecting the block to the said grasping arms, the block providing lost motion between the rod and links, the aperture in the head having a non-circular conformation and having a portion in which the intermediate large portion of the rod can reside, the aperture also having a smaller portion extending laterally of'the large portion in which the upper portion of the rod can reside but not the intermediate portion, the aperture operating when the upper portion of the rod is located in the smaller portion of the aperture and in a low position in the head to look the rod against upward movement relative to the head, means associated with the smaller portion to prevent lateral movement of the rod when it is located therein, and means to prevent the lower end of the suspension rods ii from rising unobstructedly through the aperture in the block.

5. A material handling apparatus comprising a head having a vertically-extending central aperture, grasping arms hingedly connected to the head in generally opposed relation and extending downwardly therefrom, a suspension rod extending through the said aperture and having an upper portion of small diameter and an intermediate portion of relatively large diameter, the apertureconsisting of a central bore extending vertically through the head of a diameter slightly larger than the diameter of the intermediate portion of the rod and a plurality of passages opening on the bore and extending laterally therefrom defined by parallel vertical surfaces with each passage to prevent lateral movement of the rod when it is located therein.

6. A material handling apparatus comprising a head having a vertically-extending central aperture extending vertically therethrough, grasping arms hingedly connected to the head in generally opposed relation and extending downwardly therefrom, a suspension rod extending through the said aperture the rod having an upper portion of small diameter and an intermediate portion of relatively large diameter, there being a shoulder formed in the rod between the two said portions, the aperture having a large portion and a small portion extending laterally of the large portion, the small portion being of a small size which will admit the upper portion of the rod but not the intermediate portion, a counterbore formed in the underside of the said small portion, means pivotally connecting the lower end of the said rod to the said grasping arms for the actuation thereof, the shoulder of the rod residing in the counterbore of the head when the upper portion of the rod is located in the small portion of the aperture and in a low position to lock the rod against upward and lateral movement relative to the head, and means providing a lost motion be tween the rod and link.

7. A material handling apparatus comprising a head having a vertically-extending central aperture extending vertically therethrough, grasping arms hingedly connected to the head in generally opposed relation and extending downwardly therefrom, a suspension rod extending through the said aperture, the rod having an upper portion of small diameter and an intermediate portion of relatively large diameter, there being a conical transition surface formed in the rod between the two said portions, the aperture having a large portion and a small portion extending laterally of the large portion, the small portion being of a small size which will admit the upper portion of the rod but not the intermediate portion, a conical counterbore formed in the underside of the said small portion of the aperture and having no communication with other portions of the aperture, means pivotally connecting the lower end of the said rod to the said grasping arms for the actuation thereof, the

. transition surface of the rod residing in the counterbore when the rod is located in a low position to lock the rod against upward and lateral movement relative to the head, and means providing a lost motion between the rod and link.

8. A material handling apparatus comprising a head having a vertically-extending central aperture extending vertically therethrough, grasping arms hingedly connected to the head in generally opposed relation and extending downwardly therefrom, a suspension rod extending through the said aperture, the rod having an upper porameter, there being a shoulder formed in the rod between the two said portions, the aperture having a large portion and a small portion extending laterally of the large portion, the small portion being of a small size which will admit the upper portion of the rod but not the intermediate portion, a counterbore formed'in the underside of the said small portion of the aperture, a block having a vertical bore through which extends the said lower portion of the rod, means pivotally connecting the block to the said grasping arms for the actuation thereof, the bore in the block having a diameter considerably greater than the diameter or the lower portion of'the rod, whereby the rod is capable of considerable misalignment relative to the bore, the bore in the block being considerably less'than the diameter of the intermediate portion of the rod to limit downward movement of the rod therethrough, the shoulder of the rod residing in the counterbore of the head when the rod is located in a low position to lock the rod against upward and lateral movement relative to the head, and means to prevent the lower end of the suspension rod from rising unobstructedly through the aperture inthe block.

9. A material handling apparatus comprising a head having a vertically-extending central aperture extending vertically therethrough, dependent grasping arms hingedly' connected to the head in generally opposed relationship and extending downwardlytherefrom, the arms having laterally-extending feet at their lower ends, 'asuspensi on rodextending through the said aperture, the'rod-hav ing an upper portion of small diameter and an intermediate portion of relatively large diameter, there being a conieal shoulder formed in the rod between the two said portions,

the aperture having a large portion and a small portion extending laterally from the large portion, the small portion being of such a small size as to admit the upper portion of the rod but not the intermediate portion, a

conical counterbore formed in the underside of the said small portion of the aperture, means including a lost motion' device pivotally connecting the lower end of the said rod to the saidgrasping arms for the actuation there- 'of, the shoulder of the rod residing in the counterbore of the head when the upper portion of the rodis located in the small portion of the aperture and in a low position to lock the rod against upward and lateral movement relative to the head.

References Cited in the file of this patent UNITED STATES PATENTS