US3401973A

US3401973A - Multiple point lift plate

Info

Publication number: US3401973A
Application number: US605039A
Authority: US
Inventors: Benson H Marshall
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-12-27
Filing date: 1966-12-27
Publication date: 1968-09-17
Anticipated expiration: 1985-09-17

Description

p 1968 B. H. MARSHALL 3,401,973

MULTIPLE POINT LIFT PLATE Filed Dec. 27, 1966 INVENTOR BENSON H. MARSHALL ATTORNEY United States Patent O 3,401,973 MULTIPLE POINT LIFT PLATE Benson H. Marshall, Fairfax, Va., assignor to Norwood L. Sorrell, Benson, N.C.

Filed Dec. 27, 1966, Ser. No. 605,039 2 Claims. (Cl. 294-93) ABSTRACT OF THE DISCLOSURE I A lift plate with plural radially adjustable contact bars, the bars being adapted for positioning in such manner as to be located below an article to be lifted.

CROSS-REFERENCES TO RELATED APPLICATIONS This application deals with the general subject matter of United States application Ser. No. 593,572, filed Nov. 10, 1966, by Norwood L. Sorrell, and is primarily adapted for the lifting of components of street access cover assemblies of the type described in Sorrell application Ser. No. 498,544, filed Oct. 20, 1965, now United States Patent No. 3,331,295.

BACKGROUND OF THE INVENTION (1) Field of the invention The present invention pertains to a handling or hoisting implement for imparting a vertical lift force to an object of the type requiring unilinear movement to avoid damage or binding.

(2) Description of the prior art It has heretofore been known to provide extensible lift apparatus for the lifting of sewer tops and the like. Representative of the prior patents in the field is United States Patent No. 3,206,243. In devices of that type, it is necessary that locator means be supplied on the article to be lifted, or that the positioning of the lift apparatus be very precise to avoid tilting during lift operations with consequent binding or damage to the article to be lifted.

SUMMARY OF THE INVENTION The instant invention provides a noncomplex means for vertical lifting of sewer top support walls and similar articles, the present apparatus having multiple point, extendable and retractable engagement elements insuring linear movement of the article without the necessity for positioning of the elements with preformed locators, and obviating the necessity for careful location of the elements with respect to the object to be lifted.

An important advantage of the present invention resides in the provision of a lift apparatus for linear, vertical lifting wherein the lift prime mover connector is fully effective on a single point hook-up, thus adapting the lift apparatus to use with available maintenance equipment such as fork lift trucks, front end loaders, and the like. Additional objects of the invention include the provision of a lift with extensible engagement means and further provided with stop lug means to securely position the engagement means in either extended or retracted locations thus to prevent any danger of inadvertent disengagement during a lift operation.

Still another objective concerns the provision of a new and novel lift bar connector having a nonrigid connection with its hoist cable to avoid shock damage to the article to be lifted, and to facilitate the connection of the connector and the hoist.

Other and further objects and advantages of the inven tion will become apparent to those skilled in the art from a consideration of the drawing and specification herein below.

3,401,973 Patented Sept. 17, 1968 'BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a vertical cross sectional view through a lift assembly constructed and assembled in accordance with the teachings of the invention, showing atypical preferred environment of use;

FIGURE 2 is a top plan view from the approximate plane of the line 2-2 of FIGURE 1, looking in the direction of the arrows; and

FIGURE 3 is a view similar to FIGURE 2, showing an alternative position of the engagement means.

DECRIPTION OF THE PREFERRED EMBODIMENT In FIGURE 1, a typical environment of use is illustrated, comprising paving 10 with a top surface 12 having an access opening 14 above a service casing 16. A cover wall 18 is imbedded in the paving and has an inward flange 20 supporting a height adjustment ring 22 and service lid support wall 24. The wall 24 has in inward ledge 26 Which supports the cover (not shown) in flush relation to the surface 12.

As contemplated in the aforesaid prior application Ser. No. 498,544, when an additional layer of paving is placed upon the surface 12, it is necessary to raise the wall 24 to supplement or replace the ring 22 with one of greater height. Thereafter, the wall 24 is replaced, thus raising the lid to flush relation with the new level of the paving. Lifting of the wall 24 must be in a vertical direction and it is necessary that the lift be unilinear in order to avoid binding resulting from any substantial deviation.

The present invention comprises lift apparatus 28 the basic component of which is a substantially flat, round plate element 30 having an upper side 32 and lower side 34 and a circumferential edge 36. The plate has a central opening 38 formed therein, and an elongated vertical sleeve 40 is fixed therein by welding or otherwise.

Slidably positioned in the vertical sleeve 40 is a substantially cylindrical lift rod 42 with an enlarged base 44 at its lower end and a ring 46 at its upper end. FIGURE 1 shows a hoist line 48 from a lift prime mover power source having a weight 50 and a book 52 for releasable engagement with the ring 46 of the lift rod, The sliding engagement of the rod 42 in the sleeve 40 permits the hook to be readily engaged and also, as indicated above, lessens the likelihood of shock damage.

In FIGURES 2 and 3, is Will be observed that a plurality of horizontal, tubular sleeve members 54 are welded on the top side 3-2 of the plate. The members 54 are radially positioned and are equidistantly spaced so that, where three are employed as shown, they are arranged at substantially 120 with respect to each other. Each member 54 has a slideway 56 extending fully therethrough in a radial direction and in which a substantially cylindrical, solid bar 58 is slidably mounted. The bars 58 have distal ends 60 and proximal ends 62, and right angular bars 64 are bent from the ends 62.

A pair of inner and

outer stop lugs

66, 68 is provided for each bar. The lugs are fixed to the side 32 of the plate. The inner lug is laterally elongated to prevent inward extension of the bar 58 thereby, while the lug 68 is located in such manner as to permit the bar to bypass it when the angle bar 64 is vertically positioned, but to prevent its passage when horizontal.

Referring again to FIGURE 1, it is therein to be noted that gusset plates 70 extend from the vertical sleeve 40 at locations preferably subjacent the horizontal sleeve members 54.

In operation, the assembly 28, connected to the hoist line 48 is lowered into the opening of the wall 24 to a age tothe wall and are hel'd'in such position by engagement of the angle bars 60 between the

lugs

66 and 68 as shown in FlGURE 3. Then, the bars are extended beneath the ledge and again engaged by horizontal positioning of the angle bars 64 forwardly of the lugs 68 as shown in FIGURE 2. In such position, disengagement is virtually impossible, and replacement of the ring 22 may be accomplished without difiiculty and without danger of dropping of the wall 24.

Having described and illustrated an embodiment ofthis invention in some detail, it is to be understood that this description and illustration have been offered only byway of example, and that the invention is to be limited in scope only by the appended claims.

I claim:

1. A lift assembly for vertical movement of an annular object, the assembly comprising:

a plate element of a configuration to fit within the annular object, the plate element having opposite sides;

the plate element having a central opening therein with a sleeve fixed in the opening;

a rod mounted slidably within the sleeve, the rod having hoist connection means at one end and sleeve engagement means at its opposite end;

a plurality of equidistantly spaced, radially arranged horizontal sleeves fixed on one of the side of the plate element, the horizontal sleeves having slide ways therein;

extendable and retractable engagement bars disposed slidably in the slide Ways of the horizontal sleeves and extendabl'e" therefrom to positions wherein they project outwardly of the plate and retractable to positions within the area of the plates;

the engagement bars having inner ends with angle bars thereomand r p a pair of lugs on theplate adjacent .each of the horizontal sleeves, each pair including a reduced width lug contactedby one ofthe angle bars when the engagement bars are in saidextended positions, and wide lugs contacted by the angle bars when the engagement bars are retracted.

2. Theinventionof'claim 1, wherein:

the horizontal sleeves are mounted on the upper side of the plate element; and

a gusset plate secured to the lower side of the plate element and to the vertical sleeves below each of the horizontal sleeves.

References Cited I UNITED STATES PATENTS 678,416 7/1901 Bell 294-93 1,266,653 5/1918 Barlow 29493 1,717,006 6/1929 Cartwright 29493 2,471,323 5/1949 Harrington 29493 2,759,757 8/ 1956 Pace 29493 2,809,070 10/1957 Nelson 29493 3,206,243 9/ 1965 Miles 29493 EDWARD A. SROKA, Primary Examiner.

H. C. HORNSBY, Assistant Examiner.