Floating platform lock-down mechanism for spooler troughs and doff trucks and the like

Dec. 24, 1968 j. g. fisher 3,418,031

FLOATING PLATFORM LOCK-DOWN MECHANISM FOR SPOOLER

TROUGHS AND DOFF TRUCKS AND THE LIKE

Filed Aug. 30, 1967 2 Sheets-Sheet 1

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INVENTOR

JAMES GLENN FISHER

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ATTORNEYS

Dec. 24, 1968 j. g. fisher 3,418,031

FLOATING PLATFORM LOCK-DOWN MECHANISM FOR SPOOLER

TROUGHS AND DOFF TRUCKS AND THE LIKE

Filed Aug. 30, 1967 2 Sheets-Sheet 2

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ATTORNEYS

United States Patent Office

3,418,031

Patented Dec. 24, 1968

3,418,031

FLOATING PLATFORM LOCK-DOWN MECHANISM FOR SPOOLER TROUGHS AND DOFF TRUCKS AND THE LIKE

James Glenn Fisher, Hartwell, Ga., assignor to NVF Company, Wilmington, Del. Filed Aug. 30, 1967, Ser. No. 664,458 4 Claims. (Cl. 312—319)

ABSTRACT OF THE DISCLOSURE

This invention for the lock-down mechanism is comprised of unique reinforced toggle arms that support a platform in a receptacle and said arms provide for a unique attachment for pivotally attaching a shaft thereto and carrying and uniquely supporting outwardly thereof latch rod means and a pair of spaced oppositely disposed resilient flat spring means extending forwardly of and carried by similar latch keeper means and a centrally disposed latch bar elevating means extending substantially midway between the said keeper means and the sides of a frame in which certain ends of the toggle arms are slidably maintained, and the said elevating means being so formed and of varying heights as to properly guide the latch bar onto the said springs and up over inclined edges of the keeper means and into an aligned notch in each of the keeper means and for releasing the latch rod from the keeper means to a second position of lowering of said platform supported by the toggle arms and the return of the latch rod from beneath the keeper means and snapping past the respective springs of the keeper means and being raised by the elevating means for a repetition of this movement.

An object of the invention is to provide a new lockdown mechanism for a floating spring loaded platform of a doff truck or the like embodying novel means for the cycling of the components thereof and reducing the cost of production, and such mechanism as will be simpler to clean and eliminating some of the moving parts of the prior art lock-down mechanisms and, additionally, be more positive in its cycling operation as caused by the lowering of the platform.

Another object of the invention, therefore, is to provide a new lock-down mechanism embodying unique action and carrying and mounting of a latch rod and downwardly extending inclined spring means for elevating the latch rod and positioning it in the notch of a keeper means which is the first lowered position of a platform vertically movably supported in a receptacle, and releasing the rod from this first lowered position to a second lowered position, and returning the rod from beneath said keeper means and past said spring means, and providing other means for elevating the latch rod so that it will be in a position above the ends of the spring means for a repetition of this movement.

Another object of the invention is to provide a novel lock-down mechanism having reinforced toggle arms and the toggle arms having oppositely disposed outwardly extending portions providing a space and each having an opening therein, and which said openings are aligned, and a shaft for supporting a latch rod having its respective ends mounted in said openings and extending into said space.

Still another object of the invention is to provide unique downwardly extending inclined spring means carried by latch rod keeper means for allowing elevation of the latch rod into first and second lowered positions of a vertically movably supported platform in combination with latch rod elevating means that will maintain said latch rod above the ends of the spring means so as to enable the latch rod, when moved, to ride up the same into the said locking positions and the retujn of the latch rod being so elevated that the same movements may be repeated.

In the drawings:

FIG. 1 is a side elevational view of a doff truck, partly in section, and disclosing the improved lock-down mechanism in section, and with the following platform in fully elevated position;

FIG. 2 is a sectional view showing the follower platform in its fully depressed or downward position adjacent the bottom of the truck;

FIG. 3 is a sectional view taken along the lines 3—3 looking in the direction of the arrows in FIG. 1;

FIG. 4 is a partial longitudinal sectional view disclosing the improved lock-down mechanism;

FIG. 5 is a sectional view taken on the lines 5—5 of FIG. 4 looking in the direction of the arrows and showing the lock-down mechanism in the first downward stage;

FIG. 6 is a view similar to FIG. 5, showing the lockdown mechanism in the second lowest downward stage;

FIG. 7 is a sectional view along the lines 7—7 of FIG. 5 looking in the direction of the arrows; and

FIG. 8 is a view along the lines 8—8 of FIG. 7 looking in the direction of the arrows.

The present invention is an improvement of my Patent No. 3,091,503, May 28, 1963.

The features in common with regard to my aforesaid patent are the wheel supported receptacle 10 which comprises front and back walls 12 and 13 respectively, and end walls 16. A pair of aligned and oppositely disposed casters 17 and 18 are secured to the bottom frame of the truck and are preferably fixed. The central caster 19 is preferably mounted as to swivel. There is a main frame F which is of angle iron and which has opposite sides and ends for reception therein of the lower marginal portions 20 resting on the bottom flange 21. The receptacle is open topped and has mounted therein oppositely disposed toggle arms T. The upper forward ends of each pair of toggle arms each have a guide pin 22 mounted adjacent the outer end thereof and extending through a guide slot S in a bracket B. The ends of the other toggle arms T1 are pivotally mounted in an upper bracket B2 and the opposite end B3 of the toggle arms being pivotally mounted in the frame later described. Each pair of toggle arms is centrally pivoted as at P. There is a platform 23 that is supported by the toggle arms and this platform is spring loaded by means of similarly formed coil springs C, the upper ends of which springs engage beneath the inner side of the platform and the lower ends of the springs engage in a frame described later herein.

The aforementioned structures and combinations are clearly shown in my Patent No. 3,091,503.

The improved lock-down mechanisms include a rectangular frame R having an inturned ledge R' at one end and such frame is connected at its corners by welding or riveting or the like and has at the forward ends of opposite upstanding sides thereof similar elongated slots 24. This frame rests on cross beams 25 and 26 that engage in opposite sides of the right angle main frame F. The toggle arms T1 are of different construction than in the toggle arms in my Patent No. 3,091,503. In the present invention, the toggle arms T1 are elongated and flat and each has on its inner side and welded thereto, a strip substantially similar in width to the toggle arms proper, and ad

3.418.031 jacent the lower ends the strip is curved outwardly at 27 substantially the same on each toggle arm and providing between the same a space 28.

Thus, it will be seen that the toggle arms of the present invention are greatly reinforced and, moreover, the substantially similarly curved portions each has an opening 29 therein, which openings are in alignment. The locking rod means, generally indicated at 30, includes a shaft 31 with opposite end portions thereof disposed into the said openings in the curved part of the reinforced toggle arm and extending into the said spaces 28. Attached as by welding 32 to this shaft are outwardly extending substantially flat spaced bars 33 and 34, and to the ends of the bars 33 and 34 there is welded at 35 a latch rod 36.

Mounted on the oppositely inwardly extending flanges 37 and 38 are similar keeper means 39. This keeper means, as more clearly shown in FIG. 7, is comprised of a central flat portion 4» and an upstanding flange portion 41, with a notch 42 therein and an inclined front edge 43 and a second locking position ledge portion 44 and a downwardly extending flange 45 welded at 46 to the frame R.

Attached to each forward end portion of the flat portion of the keeper means 39 is a relatively wide, flat curved downwardly extending latch rod elevating spring 47. The end of each spring extends below the elongated slot 24 as shown in FIG. 8 for a purpose later to be described.

Centrally of the frame and the oppositely disposed latch means there is a relatively wide latch rod elevator bar means generally indicated at 48, and which comprises an end flat portion 49 thereof welded as at 50 to the frame R, and then extending upwardly as at 51 and further continuing in a single plane as at 52 and curved downwardly as at 53 and welded at 54 to a brace plate X, the opposite marginal portions thereof being welded at Y to the respective opposite flanges of the frame R, and which bar 48 extends beyond the rear end 24' of each slot 24. The vertically opposite ends of the toggle arms T1 are each slidably mounted in the respective slots S and 24 by means oi the guide pin 22.

It will be noted from FIG. 4 that the high point of the inclined portion 51 of the bar 48 is in advance of the respective ends of the down-turned springs 47. There is a stop bar 55 welded at 56 to the reinforced toggle arm T1 and the end portion 56' thereof is adapted to engage the flat bar 34.

The operation of the improved lock-down mechanism is that, when the platform 23 is in the uppermost position as shown in FIG. 1, the latch rod 36 will be in engagement with the flat portion 52 of the elevator bar means 48, and as the platform is loaded and moves downwardly in the receptacle, the toggle arms slide in the slots S and 24 and on their pivots B2 and B3 and, of course, compress the coil springs in their downward movement, and when such downward movement has advanced sufficiently, the latch rod 36, which is maintained above the respective ends of the springs 47 by the highest portion of the inclined portion 51 of the bar 48, will engage the springs inwardly of their ends and will be elevated on the inclined portion thereof and then engage the sloped portion 43 of the keeper means and ride up on the same and then drop down into the notch 42, which is the first lock-down position of the platform. With continued downward movement, the latch rod will ride upwardly on the inclined portion 43' within the notch and then pass over the top of the notch portion and by gravity fall onto and be supported by the ledge portion 44 which is the lowest or second locking position of the platform, and this position is shown clearly in FIG. 2. From the second latch position, further movement of the toggle arm will move the latch rod off of the ledge and by gravity this latch rod will fall and rock on the shaft 31, and this latch rod will then, by further movement of the platform, engage the flat portion 49 of the bar means 48, and the end portions of the latch rod will be beneath the keeper means 39. On further movement, the latch rod will ride up on the inclined portion 51. The latch rod will emerge from beneath the keeper means and when doing so, the end portions of the latch rod that are beneath the springs 47 will engage the down-turned springs and snap past the same when the latch rod reaches the highest point of the incline 51, and again the latch rod will then be 5 resting on the elevated flat portion 52 of the bar means 48 for a repetition of this movement.

The components of the lock-down mechanism described and shown herein are of suitable metal.

As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined in the appended claims, and all changes that fall within the metes and bounds of the claims, or that form ,_r their functional as well as conjointly cooperative equiva° lents, are therefore intended to be embraced by those claims.