US3206243A

US3206243A - Spreader bar

Info

Publication number: US3206243A
Application number: US241768A
Authority: US
Inventors: Boyd F Miles
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-12-03
Filing date: 1962-12-03
Publication date: 1965-09-14
Anticipated expiration: 1982-09-14

Description

Sept. 14, 1965 a. F. MILES 3,206,243

SPREADER BAR Filed Dec. 5, 1962 INVENTOR. 5070 AT MIL 6 fw {W A rraeA/A'KS' United States Patent Office 3,206,243 Patented Sept. 14, 1965 3,206,243 SPREADER BAR Boyd F. Miles, P.O. Box 32, Duvali, Wash. Filed Dec. 3, 1962, Ser. No. 241,768 16 Claims. (Cl. 294-81) This invention concerns a spreader bar by which heavy loads can be engaged and lifted using a bridle or sling connected to and angled inwardly from its opposite ends to a central point above, at which point a hoist line is connected. Such spreader bars and slings are in common use in the handling of cargo. It is illustrated herein as lifting a manhole collar.

Desirably the bar engages the load by its extreme outer ends, and the bridle is connected to its outer ends, so that transfer of force from the load to the bridle through the bar is most direct. It is often necessary, as it is in the illustrative use, to shorten the spreader bar so that it may enter the load from above, and then to extend it into supporting engagement with the load, to which end one or both of the tips of the spreader bar of this invention is or are movable relative to the rigid central portion of the bar. In order to apply the ends of the bridle to the spreader bar as nearly as possible in direct line with the point of application of the load, the bridle ends are connected to the movable tips themselves. For convenience and simplicity these tips are movable by mounting them for sliding movement lengthwise of the rigid portion, and the inward inclination of the ends of the bridle produces an inward component of force during lifting, that urges the slidable tips inwardly. It follows that for safety it is necessary to lock the tips securely in their outwardly projected lifting position.

It is a primary object of this invention to provide means so to lock the tips in load-lifting position, against the possibility of their inward sliding, and to do so by means which are made effective by forces generated during lift- This object is achieved by interposing between the movable tip and adjacent end of the body of the bar a pivotal connecting link which serves as part of a mechanism by which to retract the bolt or to extend it and lock it in extended position. In locked position this link serves in compression as a rigid element physically abutted at its respective ends against shoulder-forming members or stops, one a bridle-connected pad-eye on the bolt and the other a lug on the bar body, thereby to transmit compression loading from the bolt directly to the bar body without total dependence upon pivotal connections of the link. One end of the rigid element is pivotally coupled directly to one shoulder member and the opposite end is connected to the other shoulder member through an operating lever or link pivoted on such latter member and in turn pivotally connected to such opposite end of the rigid element in order to move the rigid element into and from its locking position interposed between the shoulder-forrning members.

Further, as another important safety feature, the pivot locations are so offset in relation to the line of compressive loading of the rigid element in its locked position, that such loading exerts torque on the ends of the element pressing it more firmly to its seat in locking position against the bar, thereby precluding accidental release under load. The greater the load, the greater this retaining effect.

As still another feature and object this same pivot arrangement assures direct lateral retraction of abutment surfaces on the link from cooperating shoulder member surfaces when the rigid element (and bolt) is being retracted, rather than frictional sliding retraction. Consequently, no matter how great the load within the limitations of the device binding of the bolt mechanism in extended position is precluded positively.

It is also an object to provide such a spreader bar of simple and inexpensive construction, yet thoroughly rugged and easily handled.

The spreader bar of this invention is shown in the accompanying drawings in a form presently preferred by me, and also in a somewhat modified form.

FIGURE 1 is an elevational view of the spreader bar, in use, the manhole collar that constitutes the load being shown in axial section.

FIGURE 2 is an elevational view of an end of the bar, partly broken away, with parts in the load-sustaining position.

FIGURE 3 is a view similar to FIGURE 2, but with parts in full lines moved toward released position from the load-sustaining position that is shown in dot-dash lines.

FIGURE 4 is an isometric View of the end of the spreader bar, with parts in the load-sustaining position.

FIGURE 5 is a view similar to FIGURE 4, showing a modified construction.

The load, which is typical of any load with which such a spreader bar can be used, is represented as the cast-iron manhole collar C, having a flange F where the manhole cover will seat, and formed at two opposite points with holes H within which the tips of the spreader bar may engage, once they have been retracted to permit entrance from above and are then extended. Whether one tip only is thus retractable and extensible, or both such tips, is immaterial. The spreader bar is shown with both its tips so movable, and a description of one will suflice for the other.

The spreader bar includes the rigid central body portion or bar 1, which may be of tubular cross section, and a pair of tips or bolts 2 each slidably received and guided in the ends of the body portion 1. The portion 1 is of a length less than the distance between holes H, so that it may enter from above and extend diametrally of the collar C when the tips 2 are retracted. When they are extended, however, and enter the holes H, the collar C may be lifted by a sling or bridle B which is secured at 31 to each of the tips 2, or to pad-eyes 3 which stand up from the respective tips or bolts 2. Both cables of the bridle B incline or converge inwardly from the points of connection at 31, and a lifting force at its center produces an inward component of force at 31, urging these two points inwardly or towards one another.

A shoulder or stop 11 is defined by the outer edge of a lug 12 upstanding from and fixed upon the rigid portion 1. A cooperating shoulder or stop 33 is defined by the inner edge of the pad-eye 3. These stops 11 and 33 face one another, and preferably are perpendicular to the axis of the spreader bar. They are spaced apart by a given distance when the spreader bar is extended, and by a lesser distance when it is contracted. The end 3 of the tubular part 1 may beslotted at for inward movement of the pad-eye 3.

A rigid element is arranged for interposition directly between stops 11 and 33 when the bolts are extended. In the preferred form this element has a length just equal to the greater spacing between the stops 11 and 33, so that in its operative position the rigid element seats at its respective ends upon each of these stops. It is pivoted at 53 upon the pad-eye 3. Its operative position is shown in FIGURES l, 2 and 4. An operating lever or link 5 is pivoted at 51 upon the lug 12, and at 54 to the compression element 4. In the operative or extended position of the parts the link 5 extends outwardly, as in FIG- URES 1, 2 and 4, whereas when it is desired to retract the bolt 2 the link 5 is swung upwardly and inwardly, as in FIGURE 3. The geometry is such that upward swinging of the link 5 first urges the bolt 2 outwardly, before it can slide inwardly. This cannot happen while lifting a load.

In the operative or load-lifting position the rigid element 4 seats at its ends upon the stops 11 and 33. The I pivots guide it to this seating, and they may be sufiiciently loose to ensure proper seating. The location of pivot 54 nearer the axis of portion 1 than

pivots

51 and 53 ensures that the link 5 will be drawn toward the tubular portion 1, rather than away from the same, by an inward force lengthwise of the bolt 2, and the link 5 seating upon the portion 1 is retained in thi position. The inward pull of the legs of the bridle B, acting upon the pad-eyes 3 to which they are attached at 31, produces such an inward force. When the link 5 is swung upwardly and inwardly, as in FIGURE 3, it pulls upon the pad-eye 3 through the rigid element 4, causing retraction of the bolt 2. A handle 50 enables swinging of the link 5 in either direction.

In achieving the described objectives link pivot 53 is located above the line of compressive force borne by the link in its locked position (FIGURE 2); thus retraction of the link swings its adjacent end laterally away from stop 33 (FIGURE 3) without a tendency to bind as would be the case with a locking device functioning by frictional restraint. The same is true of the opposite end of rigid element 4 in its retraction from stop 11. In both

instances pins

53 and 51 define arcs of swing for the respective ends of element 4 producing the aforementioned direct lateral separation of abutted surfaces. Moreover, placement of pins 51 generally above the line of compression loading in rigid element 4 and above the location of pin 54 with the link in locked position assures that load forces will only serve to increase the seating pressure of element 4 against body 1 and will not tend to unlock the mechanism holding the bolt 2, extended.

The form shown in FIGURE 5 omits the link 5, and for the pivotally mounted compression element substitutes a block or blocks 4a, acting as shims physically interposed between stops 11 and 33a. The latter stop need not be at the pad-eye 3, but may be offset inwardly therefrom upon an arm or arms 35 which extend from the pad-eye 3 inwardly past the lug 12. Two such arms may straddle that lug, and so hold the lug and the pad-eye in a common plane. As many blocks 4a as are needed can be held in place by through bolts 45.

As can be seen the bolt or bolts 2 are retracted by withdrawing blocks 4a in FIGURE 5, or by swinging link 5 as in FIGURE 3. This shortens the over-all length of the spreader bar sufficiently that it can enter the collar C. The bolt or bolts are then extended until the spreader bar at both ends is engaged in the holes H of the load. An upward force applied to the central portion of the bridle B urges the lower ends thereof inwardly, and this force acts upon the pad-eyes 3 of the bolts 2. They transmit this force directly through the compression element 4 to the stops 11 of lugs'12, upon the rigid portion 1 of the spreader bar. Since the geometry is such that the rigid element 4 cannot disengage under such circumstances, it follows that the load is securely engaged, the inward force is resisted by the rigid element, and the load can be lifted without danger of collapse of the spreader bar. When the load is set down the bolts 2 are readily withdrawn, and the spreader bar is relieved of the load.

The outer tip 20 of the bolts 2 are shown of reduced size. This is a matter of convenience, and these tips would be made amply strong to support any intended load. It will be noted in FIGURES 1 and 2, in particular, that the legs of the bridle B are directly in line with these outer tips, where the latter engage the load, which imposes the least strain upon the parts, under load, but which imposes upon the slidable bolts the tendency to slide inwardly, which tendency is so well resisted by the structure of this invention. The primary purpose of the bar 1 is to act in compression, and the linkage of this invention imposes all loads in compression upon the bar 1.

I claim as my invention:

1. A spreader bar for lifting a load at opposite relatively fixed points of engagement, comprising a rigid bar of a length somewhat less than the distance between such points, means at one end to engage the load at one such point, a bolt mounted upon the bar for sliding lengthwise at its opposite end, outwardly into and inwardly from engagement with the load, a first stop upstanding from the bar rigid, a second substantially coplanar stop upstanding from the bolt, spaced from and aligned with the first stop, a rigid element pivotally connected at one end to one of said stops, to swing in the plane substantially common to said stops, and of such length that when the bar is engaged at both ends with the load said rigid element extends lengthwise of the bar, and engages each of the two stops, for direct transmission in compression of any force tending to withdraw said bolt inwardly from engagement with the load and an operating link pivotally connected to the other end of the rigid element, and to the other stop, and which when the rigid element is engaged with both stops lies alongside the rigid element, but is swingable about its pivot connection to the stop to withdraw the rigid element from engagement with that stop.

2. A spreader bar as in claim 1, wherein the pivot connectlon between the operating link and the rigid element l es more nearly adjacent the bar than the pivot connectron between said link and its stop and the rigid element and its stop, respectively, when the rigid element is engaged with the two stops.

3. A spreader bar as in claim 1, including a pad-eye upstanding from the bolt, for securement of one angled leg of a lifting bridle, and means upstanding from the opposite end of the bar for securement of a second oppositely angled leg of the bridle, whereby the legs of the bridle tend to draw the bolt inwardly to urge the second stop against the rigid element and the latter against the first stop.

4. A spreader bar as in claim 3, wherein the second stop is formed as part of the pad-eye.

5. A spreader bar for lifting a load by engaging it at two relatively fixed points of engagement at opposite sides of the load comprising a rigid bar of a length somewhat less than the distance between such points, means at one end of the bar to engage the load at one such point, a bolt guided for movement lengthwise of'the opposite end of the bar outwardly into and inwardly from engagement with the load at the opposite point of engagement, a first stop upstanding from the bar near the latter end, a second stop upstanding from the bolt, outwardly of and spaced from said first stop, a rigid element pivotally connected to said second stop at a given spacing from the bolt, to swing in the plane of the bar, an operating link pivotally connected to said first stop at a given spacing from the bar, also to swing in the same plane, said link being also pivotally connected to said rigid element at the latters end which is opposite its pivotal connection to the second stop, the rigid element being of a length equal to the spacing between the stops, and engaging each thereof, when the parts are in the bolt-extended lifting position, and the pivotal connection between the link and the rigid element being then located inwardly of a line joining the pivotal connections to the two stops, whereby compressional force in the rigid element urges the latter to a seat upon the bar.

6. A spreader bar as in claim 5 including a duplicate bolt, stops, rigid element, and link at the other end of the bar, constituting the means at this end for engagement with the load, and a load-lifting means engaged with each of the bolts, and urging them together.

7. Means for lifting a load such as has a top opening, comprising a spreader bar for disposition transversely within such opening, a movable means at an end of said spreader bar guided thereon for lengthwise retractive movement to enter the opening, and for lengthwise extending movement to engage the load, a bridle having two legs depending and angled outwardly from a point of application of a lifting force, the lower end of one leg being secured to said movable means, and the lower end of its other leg being secured to the opposite end of the spreader bar, a first stop upstanding from the spreader bar inwardly of the movable means, a second stop upon the movable means outwardly of the first stop, an elongated rigid element pivotally connected at one end to the second stop and extending inwardly therefrom along the spreader bar, and a link pivotally connected at spaced points thereon to the opposite end of the rigid element and to the first stop, respectively, to guide movement of the rigid element between an operative position interposed bodily between the stops and a retracted position withdrawn from between the stops and in turn thereby retracting inwardly the movable means by swinging of the link about its pivot on the first stop.

8. A spreader bar for lifting a load at opposite relatively fixed points of engagement, comprising an elongated rigid bar body of a length slightly less than the distance between such points, and load engaging means mounted on each end of said body, at least one such means comprising an extensible member mounted in longitudinally slidable relation to the body, and having means therein forming a first abutment, means on said body forming a second abutment spaced longitudinally from the first abutment, a rigid element interposable directly between said abutments to resist retraction of said extensible member and at one end pivotally connected to one abutment means, an operating lever pivotally connected to the other abutment means and to the rigid element at a point on the latter spaced longitudinally from its pivotally connected end, whereby swinging of such lever laterally away from the body swings the rigid element outwardly therefrom and retracts the extensible member, and means on the body limiting inward swinging of such lever at a position in which the effective line of compression force transmitted by the rigid element to said other abutment means lies inside the pivotal connection of the lever to said other abutment means, in relation to the body.

9. A spreader bar for lifting a load at opposite relatively fixed points of engagement, comprising an elongated rigid bar body of a length slightly less than the distance between such points, and load-engaging means mounted on each end of said body, at least one such means comprising an extensible member mounted in longitudinally slidable relation to the body, and having means therein forming a first abutment, means on said body forming a second abutment spaced longitudinally from the first abutment, a rigid element interposable directly between said abutments to resist retraction of said extensible member and at one end pivotally connected to one abutment means, an operating lever pivotally connected to the other abutment means and to the rigid element at a point on the latter spaced longitudinally from its pivotally connected end, whereby swinging of such lever laterally away from the body swings the rigid element outwardly there- ,from and retracts the extensible member, and means on the body limiting inward swinging of such lever at a position in which the pivotal connection between said lever and rigid element lies inside the pivotal connection of the lever to said other abutment means, in relation to the body.

10. The spreader bar defined in claim 9, wherein the pivotal connection first-mentioned lies outside the effective point of contact between the adjacent end of the rigid element and the abutment engaged thereby, in relation to the body. 7

11. The spreader bar defined in claim 10, wherein the operating lever is pivotally connected intermediate its ends to the end of the rigid element opposite the firstmentioned end of the latter.

12. The spreader bar defined in claim 11, wherein the body comprises a tubular member in which the extensible member is received in telescoping relationship, and the first abutment comprises a pad-eye projecting transversely from the extensible member on the same side of the body as the second abutment and has means thereon adjacent the outer end of the extensible member to which a lift bridle may be fastened.

13. A sling of the character described for lifting a load at opposite relatively fixed points of engagement, comprising a rigid spreader bar of a length somewhat less than the distance between such points, means carried by said bar at one end to engage the load at one such point, a bolt mounted upon the bars opposite end for sliding lengthwise of the bar, a rigid element pivotally connected to said slidable bolt, a link pivotally connected to the bar and to said rigid element, and movable between an inoperative and an operative position, in which latter position the bolt is projected into engagement with the load, and the link and rigid element contact the bar, with the pivot of the link upon the rigid element located inwardly of a line joining the pivots of the link upon the bar and of the rigid element upon the bolt, whereby compression forces tending to retract the bolt are resisted through said rigid element, and two bridle lines converging upwardly from the opposite load-engaging ends of the bar and of the bolt, and thereby urging retraction of the bolt.

14. A sling as defined in claim 13, including two stops outstanding from the bolt and from the bar, respectively, and located and' spaced apart to be engaged by the opposite ends of the rigid element when in its operative position, to transmit compressional forces between the bolt and the bar directly through said rigid element.

15. Means for lifting a load such as 'has a top opening, comprising a spreader bar for disposition transversely within such opening, a movable means at an end of said spreader bar guided thereon for lengthwise retractive movement to enter the opening, and for lengthwise extending movement to engage the load, a bridle having two legs depending and angled outwardly from a point of application of a lifting force, the lower end of one leg being secured to said movable means, and the lower end of its other leg being secured to the opposite end of the spreader bar, a first stop upstanding from the spreader bar inwardly of the movable means, a second stop upstanding from the movable means outwardly of the first stop, a rigid element located externally of the spreader bar and bodily but removably interposed between said stops, to space them apart and to maintain the movable means during lifting in its extended position, said means for lifting a load further including an arm directed lengthwise of the bar from the second stop alongside the first stop, the two stops when in an operative position being spaced apart by a definite distance, and wherein the rigid element constitutes a member of a length equal to such distance, removably interposed between the stops and upstanding from the spreader bar.

16. Means for lifting a load such as has a top opening,

comprising a spreader bar for disposition transversely within such opening, a movable means at an end of said spreader bar guided thereon for lengthwise retractive movement to enter the opening, and for lengthwise extending movement to engage the load, a bridle having two legs depending and angled outwardly from a point of application of a lifting force, the lower end of one leg being secured to said movable means, and the lower end of its other leg being secured to the opposite end of the spreader bar, a first stop upstanding from the spreader bar inwardly of the movable means, a second stop upstanding from the movable means outwardly of the first stop, a rigid element located externally of the spreader bar and bodily but removably interposed between saidstops, to space them apart and to maintain the movable means during lifting in its extended position, said means for lifting a load further including two arms directed lengthwise of the bar from the second stop and straddling the first stop, the upstanding member which constitutes the rigid element being received between said arms;

References Citedby the Examiner UNITED STATES PATENTS 800,782 10/05 Adams 251-280 2,471,323 5/49 Harrington 294-93 FOREIGN PATENTS 11,027 1888 Great Britain.

ROBERT B. REEVES, Acting Primary Examiner.

RAPHAEL M. LUPO, ANDRES H. NIELSEN,

Examiners.

Claims

1. A SPRADER BAR FOR LIFTING A LOAD AT OPPOSITE RELATIVELY FIXED POINTS OF ENGAGEMENT, COMPRISING A RIGID BAR OF A LENGTH SOMEWHAT LESS THAN THE DISTANCE BETWEEN SUCH POINTS, MEANS AT ONE END TO ENGAGE THE LOAD AT ONE SUCH POINT, A BOLT MOUNTED UPON THE BAR FOR SLIDING LENGTHWISE AT ITS OPPOSITE END, OUTWARDLY INTO AND INWARDLY FROM ENGAGEMENT WITH THE LOAD, A FIRST STOP UPSTANDING FROM THE BAR RIGID, A SECOND SUBSTANTIALLY COPLANAR STOP UPSTANDING FROM THE BOLT, SPACED FROM AND ALIGNED WITH THE FIRST STOP, A RIGID ELEMENT PIVOTALLY CONNECTED AT ONE END TO ONE OF SAID STOPS, TO SWING IN THE PLANE SUBSTANTIALLY COMMON TO SAID STOPS, AND OF SUCH LENGTH THAT WHEN THE BAR IS ENGAGED AT BOTH ENDS WITH THE LOAD SAID RIGID ELEMENT EXTENDS LENGTHWISE OF THE BAR, AND ENGAGES EACH OF THE TWO STOPS, FOR DIRECT TRANSMISSION IN COMPRESSION OF ANY FORCE TENDING TO WITHDRAW SAID BOLT INWARDLY FROM ENGAGEMENT WITH THE LOAD AND AN OPERATING LINK PIVOTALLY CONNECTED TO THE OTHER END OF THE RIGID ELEMENT, AND TO THE OTHER STOP, AND WHICH WHEN THE RIGID ELEMENT IS ENGAGED WITH BOTH STOPS LIES ALONGSIDE THE RIGID ELEMENT, BUT IS SWINGABLE ABOUT ITS PIVOT CONNECTION TO THE STOP TO WITHDRAW THE RIGID ELEMENT FROM ENGAGEMENT WITH THAT STOP.