US2604251A - Stepladder - Google Patents

Description

July 22, 1952 A. F. GAUGHAN 2,504,251

STEPLADDER Filed Sept. 19, 1947 2 SHEETS-SHEET 1 Ila.

JNVENTOR.

dttorne s y 22, 1952 A. F. GAUGHAN I 2,604,251

STEPLADDER Filed Sept. 19, 1947 2 SHEETS-SHEET 2 INVENTOR. F.

a M-zr (9% altar/1 y s Patented July 22, i952 UNITED STATES PATENT OFFICE V STEPLADDEE Anthony F. Gaughan, Cleveland, Ohio Application September 19, 1947, Serial No. 774,979

Claims. 1

This invention relates to stepladders, especially to utility stepladders of the type adapted for general household use.

Heretofore, there have been a great variety of stepladder-s provided for household use and some stepladders, when initially produced, possibly have been adapted for rigid support of a person climbing up and downthe ladder. However, no stepladder known to me is available for permanent, safe use. Most household stepladders made today are of flimsy construction and are poorly engineered whereby they do not support a person safely and are the cause of many household accidents. These prior stepladders have not provided any hand rails for the safety of the user, and where movable step units have been provided, such unit has'been dependent upon the frame for support One difiiculty in household stepladders is that they are carried around by the housewife and hence must be lightweight without sacrifice of strength. This weight limitation is merely one of the factors which has prevented, heretofore, the provision of a safe household stepladder. Due to the physical abuse of a household stepladder, even if it was originally of sturdy construction, the hard usage of same would weaken and loosen thestepladder so that it had no real safety after any period of extended use.

The general object of this invention is to avoid and overcome the disadvantages of and difficulties with previous types of utility stepladders and to provide a stepladder which is characterized by its light weight, sturdy construction, and safeguards for the person using same.

Another object of the invention is to provide a stepladder of the class described wherein the stepladder is of rigid construction adapted to maintain its original rigidity in operation even after extended periods of use;

Another object of the invention is to provide a light weight metallic utility stepladder which has relatively movable parts having definite op erative and inoperative relative. positions.

A further object is to provide hand holds for the user of a stepladder and guards on the top step of the stepladder to overcome the fear of the user in ascending and descending the ladder or in working when on it.

Another object of the invention is to provide a stepladder with relatively movable parts which can be locked in both operative and inoperative relationship. 1

A further object of the inventionis to provide a stepladder having relatively movable parts 2' wherein the parts are retained permanently in engagement when once assembled.

A further object of the invention is to provide a positive method of engaging a reinforcement member with an elongate member with minimum apparatus and assembly costs.

Another object of the invention is to lock an open centered reinforcement to a tubular frame so as to prevent relative movement of the reinforcing member and the frame.

The foregoing and other objects and advantages of the'invention will be made apparent as the specification proceeds.

Reference now is made to the accompanying drawings wherein:

Fig. 1 is a side elevation of a stepladder, embodying the principlesof-the invention, shown in operative position;

Fig. 2 is a front elevation of the stepladder of Fig. 1;

Fig. 3 is a fragmentary section on line 33 of Fig. 1;

Fig. 4 is a fragmentary vertical section on line 44 of Fig. 3;

Fig. 5 is a side elevation of the stepladder of Fig. 1 shown in inoperative position;

Fig. 6 is a perspective view of the wedge element shown in Figs. 3 and 4;

Fig. 7 is av fragmentary section through the tray and itslsupport means;

Fig. 8 is a fragmentary section showing the locking action of the support tray;

Fig. 9 is a fragmentary section indicating the manner of locking the step riser unit in operative position; and

. Fig. 10 is a fragmentary elevation with parts broken away to indicate the manner in which the step riser unit is carried in an inoperative position.

Attention now is directed to the details shown in the accompanying drawings, and a stepladder indicated generally at E0 is provided. Normally the stepladder I0 is formed from light weight metals, such as aluminum or magnesium or alloys thereof so as to provide requisite strength without making the stepladder undesirably heavy. The portions of the'stepladd'er may be formed from tubing, bars, castings, welded sections, etc. as desired, whichever more eflicient and effective for a given portion of the stepladder. The stepladder I B has two main frame elements H, usually tubular, which are shaped to inverted U- shape and are of relatively greater width at their base portions than at their tops. Suitable pads l2, usually resilient, are engagedwith the bottom ends of the elements II so as to protect the bottom portions of the stepladder from damaging the supporting surface in any manner. The frame elements I I are formed into a main frame unit by means of an upper and a lower open centered, rectangular reinforcing member or ring I3 and I4, respectively, which .are secured to the elements I I intermediate the ends thereof in a manner described hereinafter in detail. A step tread member I5, of any suitable com-position, is carried by the upper ring I-3 and may be secured thereto, as desired.

Fig. 3 brings out that the reinforcing rings I3 and I4, which are of similar construction, are provided with arcuate corner portions 26 that are primarily formed in the front and rear parts of the rings and are adapted to engage with substantially one-half the periphery of the tube from which the frame elements I I and I2 are constructed. These corner portions 26 are provided with opposed, inwardly extending, overhanging lugs I6 which may be formed integrally with the ring body. The lugs I6 are each provided with an inwardly tapered, and downwardly extending surface II, adapted to engage with a substantially right angularly shaped wedge I8 which has surfaces I9. adapted to engage with the tapered surfaces II formed on the lugs and press an arcuate surface 2I formed on the wedge I8 into engagement with the frame element II. If necessary, the wedge I8 can be tapped or hammered downwardly with relation to the ring I3 or I4, so as to force the wedge to seat tightly on the lugs I 6 and against the portion of the frame element confined thereby. Relative axial movement of the rings I3 and I4 with relation to the frame elements I I is prevented by means of associated recesses in the frame and Drotuberances on the rings that engage with each other. This action may be effected by pressing or otherwise forming inwardly directed cut-out lips 22, as shown in Fig. 4, on spaced vertical portions of frames II which lips 22 may have recessed portions 23 therearound. An inwardly directed lug 24 is formed integrally with the ring I 4 and such ing 24 engages withand seats on the lip 22 whereby the reinforcing ring is secured to the frame elements and relative movement therebetween is prevented after the wedge I8 is positioned. In some instances, it may be desirable to use a set screw 25 in the wedge I8 so as to prevent the wedge from slipping out of its looking position. When the securing means or device of the invention i used for securing other reinforcing members to elongated articles, the corner portions of the reinforcing element will, of course, be adapted to conform to the contour of the elongate member. Usually, the reinforcing rings I3 and I4 are formed from castings which have the lugs I6 and 24 formed integrally therewith.

By securing the reinforcing rings I3 and I4 to the frame element II, a main frame unit of sturdy, solid construction is provided. This main frame element supports the one step tread I which is elevated an appreciable distance from the foot sections of the frame.

In order to provide regular, stepped access to the upper step tread I5, a step unit indicated generally at 21 is pivotally associated with the main frame unit for movement from operative to inoperative relationship therewith. The stepped unit 21 includes reticulated end members, or step riser frames 28 which usually are formed from light weight metal formed to desired shape. by casting, and which have a plurality of elongate openings 28- and one large opening 33 therein. The step frames 28 are secured together by means of step treads 29 and 38 that are bolted thereto and, in some instances, by a reinforcing bar 3| which extends therebetween. The step riser frames 28 are of an open lattice work construction so as to provide the desired strength and durability without the use of excess weight. The periphery of the frames 28 is continuous except for a break,or opening 32 in each frame that connects to the centrally positioned, relatively large opening 33 in the bottom of the frame. Provision of the breaks or openings 32 in the frames permits the frames 28 to be threaded into engagement with the front section I4 of the reinforcing ring I4 so that the step frame can be permanently coupled thereto. The lowest step tread 30 is secured to (and extends between) the frames 28 after the frames are threaded into engagement with the front section I4 of the ring I4 to retain the step unit assembly in engagement with themain frame unit of the stepladder as such tread bridges over the openings 32.

Fig. 9 of the invention illustrates another feature of the invention which is the provision of a locking recess 34 in the upper rear portion of each of the frames 28 in the part thereof defining the openings 33. The recesses 34 are formed of substantially rectangular shape and are adapted to engage fixedly with the front bar It of the reinforcing ring whereby, when the step unit is placed in operative position, the recesses 34 engage with the front bar I4 and fixedly retain the step unit in association with the main frame of the stepladder. At the same time, the then base portion of the frames 28 are exactly level with the bottoms of the foot pads I2 so that the step unit 21 will normally. be supported on the member supporting the stepladder I0, although if no other support is present, the engagement between the front frame section I I and the frame recess 34 is sufficient to retain the step unit 21 in a desired position.

Pivotal movement of the step unit with relation to the remainder of the stepladder is controlled by means of slots 35 formed in each of the frames 28. The slots 35 extend upwardly and forwardly from the rear, lower portions of the frames 28 and they receive a pivot pin or bar 36 that is secured between the frame elements II at the lower front portion thereof. The slots 35 are so formed as to permit the step unit to be lifted and swung backwardly with relation to the rest of the stepladder to permit disengagement of the recesses 34 from the section I4. Fig. 9 also shows that an appreciable portion of the-step unit stands rearwardly of the pivot bar 36 and is adapted to engage with the supporting surface of the stepladder so that this aids in retainin the step unit engaged with the front bar I4 of the reinforcing ring and prevent accidental disengagement of the recesses 34 and bar I4 when the ladder is in use.

Another important element of the invention is that a bumper pad 31, usually formed of rubber-like material, is secured to the forward, lower portion of each of the frames 28 and extends into the openings 33 thereof, as shown in Figs. 1 and 10. Integral lugs 38 may be associated with the frames 28 to aid in positioning the bumpers 31 which are adapted to abut against the front bar' I4 of the lower reinforcing ring when the step unit 21 is swung'inwardly of the stepladder to its inoperative position. This abutment of the bumper 31 against the reinforcing ring |4 permits the stepladder to be carried easily, when the unit 21-is inoperatively positioned,- since the step unit .21 will be retained against the front bar I4 by gravity.

Another salient feature of the invention is that a tray 4| is pivotally attached to the upper portions of the frame elements H and extends therebetween for load support. The tray 4| has an upwardly extending flange 42 formed thereon and a hole or opening 43- (Fig. 7) is provided in the tray surface adjacent its free edge. A support arm 44 for the tray 4| is pivotally attached to the frame elements H, as by being secured to a reinforcing bar 45 extending therebetween. This reinforcing bar 45 carries a pair of L-shaped brackets 46 which journal a pin 41 that extends therebetween on which the base endfof the arm 44 is supported. The tray 4| is adapted to be swung downwardly of the stepladder when it is not being used so that in its inoperative position, the tray extends down substantially parallel to the rearsurfaces of the frame elements H and is immediately thereadjacent. Downward movement of the tray 4| preferably is limited and a stop plate 48 is provided which is secured to the bar 45 in any convenient manner, so that the tray 4| will strike such plate and further arcuate movement inwardly of the stepladder will be prevented. So as to lock the tray 4| in inoperative position, a cam surface 5| is provided on the base end of the support arm 44, as indicated in Fig. 8. The cam 5| protrudes appreciably above the pivot shaft 47! eccentrically thereto so that the base end of the support arm can be used to retain the tray in inoperative position. In moving the tray to such position, it is necessary to retain the support arm 44 in substantially horizontal position until the tray is swung down against the stop plate 48, after which the support arm can be completely lowered and the cam 5| will at that time extend upwardly a sufficient distance to lock the tray in inoperative position.

Means are provided for locking the tray 4| in its operative or load carrying position and they comprise a specially contoured end surface formed on the free end of the support arm 44 so that it can be fixedly engaged with the hole 43 in the unsupported portion of the tray. Hence the free end of the support arm 44 is cut off to roughly V-shape with a lug 52 being formed on one end surface of the support armso that its end does not comprise a conventional V-shape but has the lug 52 formed on one surface thereof. This lug is of generally rectangular shape with its outer surface parallel to the end surface on which the lug is formed. Fig. 7 best shows the shape of the free end of the arm 44 and it shows that a recess 53 is cut into the free end of the arm 44 at the base portion of the lug 52 from the edge surface of the support arm other than that on which the lug is formed. The support tray 4| is adapted to engage with the recess 53 and be retained in a locked load supporting position with relation to the remainder of the latter. The tray 4| can easily be released for movement to inoperative position by pushing the free end of the support arm inwardly of the latter a slight distance, which may raise the surface of the tray slightly, so as to disengage the tray 4| from the recess 53. the support arm 44 could be lowered and be completely disengaged from the tray 4| after which the support arm could be held in substantially horizontal position while the tray 4| is moved down against the stop plate 48 after which the Next support arm 44 should be moved to its vertically downwardly extending position wherein cam 5| locks the tray 4| against the stop plate 48. Fig. '7 shows that one edge surface 54 formed on the end of the support arm is horizontally positioned when in operative association with the support tray 4| and this surface also'engages with the tray to support same.

From the foregoing it will be seen that the stepladder I!) of the invention is provided with a ste unit and a support tray both of which can be locked in both operative and inoperative positions whereby the unit can be easily carried without the movable portions of the stepladder loosely falling around to interfere with transit of the stepladder. Of course, the safety of the stepladder of the invention is provided by the locked positioning of the stepladder units when positioned for load receipt. Thestepladder can be made of any desired size and by provision of the outwardly flaring base section of the frames the stepladder is provided with supporting feet that are widely positioned to provide a safe, well-balanced stepladder the action of which is enhanced by the step unit 21 being locked in operative association therewith and also engaging with the supporting surface for the stepladder. As above indicated, the securing means used for engaging the reinforcing members I3 and M with the frames may be used in other apparatus but is especially useful in securing open centered metallic members to elongate frames in a positive manner.

Fig. 1 clearly shows that the upper sections I l of the frames extend up'froin the tread l5 2. distance substantially equal to the height of the tread I5 from the floor so that these frame sections provide hand rails, or hand holds for a person ascending, descending, or working on the ladder. Such rails greatly add to the safety of the ladder and eliminate fear in the person using the ladder. Figs. 2 and '7 show that a rod 6| extends between the upper rear portions of the frame sections to journal the tray 4| thereon. Nuts 62 engage with the ends of rod 5| to secure same tightly between the frame with suitable Washers being provided to facilitate rotary movement of the tray. The bar 45 may have lugs (not shown) formed thereon similar to the lugs 24 and seat in similar recesses and lips to the recesses 23 and lips 22. In all events, the bar 45 may be com-' pressed between the frames by means of the rod 6| to reinforce the upper frame sections.

Fig. 9 shows that a slight clearance is provided at the top of the slots 35 and recess 34 when the step riser unit 21 is in its operative position. This insures that the unit 21 is independent of the frame unit and transmits its load directly to the supporting surface. It also effects such load transmittal even though a slightly irregular support surface is provided. Due to the reduced depth of the frame sections H the load on the ladder is centered thereon and adds to the stability of same. Furthermore, should the ring I 3 become disengaged from the means securing it to the frame, the enlarging frame sections directly below the ring |3 will support the ring for continued load support. It may even be desirable to support the ring I3 initially by this wedging action in some instances.

Spacers 63 are shown between the step riser unit 21 and frames on the bar 36 to center the unit 21. Other reinforcing members for the frames, may be provided in place of, or in addition to, those disclosed herein when desired but it is thought that the construction shown provides a sturdy, light weight, safe stepladder of desirable load support action.

While one complete embodiment of the invention has been disclosed herein, it will be appreciated that modification of this particular embodiment of the invention may be resorted to without departing from thescope of the invention as defined by the appended claims.

Having thus described my invention, what I claim is:

l. A light weight utility stepladder comprising a pair of substantially inverted U-shape light weight tubular frames, reinforcing means associated with the said frames, means securing said reinforcing means to said frames at spaced vertical points intermediate the ends thereof to form a unit therewith, an upper step secured to the upper of said reinforcin means, a pair of light weight substantially open metallic step riser frames each of which defines a plane, a pair of steps secured to and extending between said step frames to form a unit therefrom, said step frames being threaded into engagement with one section of the lower of said reinforcing means prior to attachment of said steps thereto, each of said step frames having an upwardly and forwardly directed elongate arcuate slot formed therein adjacent the rear thereof, and a pivot bar extending through said slots and secured to said step frames to secure the unit formed thereof to said first frame unit for arcuate movement from an operative position substantially without the said first frame to an inoperative position substantially within same, each of said step frames having a recess formed therein for engaging with the lower of said reinforcing means to retain said step unit in operative relation to said first frame unit, portions of said step frames being adapted to abut on the lower of said reinforcing means to limit the downward arcuate movement of said step unit when swung in to its inoperative position.

2. A light weight utility stepladder comprising a pair of substantially inverted U-shape light weight tubular frames, reinforcing rings associated with the said frames, means securing said rings to said frames at spaced vertical points intermediate the ends thereof to form a unit therewith, an upper step secured to the upper of said rings, a pair of light weight substantially open metallic step riser frames each of which defines a plane, a reinforcing bar secured to and extending between said step frames, a pair of step treads secured to and extending between said step frames to form a unit therefrom, said step frames being threaded into engagement with one section of the lower of said rings prior to attachment of said step treads thereto, each of said step frames having an upwardly and forwardly directed elongate arcuate slot formed therein adjacent the rear thereof, a pivot bar extending through said slots and secured to said step frames to secure the unit formed thereof to said first frame unit for arcuate movement from an operative position substantially without the said first frame to an inoperative position substantially within same, and means for locking said step frame unit in operative position.

3. A light weight utility stepladder comprising a pair of substantially inverted U-shape light weight tubular frames, reinforcing members associated with the said frames, means securing said members to said frames at spaced vertical points intermediate the ends thereof to form a unit therewith, an upper step tread associated with the upper of said members, a pair of light weight substantially open metallic step riser frames, a pair of step treads secured to and extending between said step frames to form a unit therefrom, said step frames having openings therein through which they are threaded into engagement with one section of the lower of said members prior to attachment of said step treads thereto, one of said treads in assembled position covering said openings, each of said step frames having an upwardly and forwardly directed elongate arcuate slot formed therein adjacent the rear thereof, and a pivot bar extending through said slots and secured to said frames to secure the step unit to said first frame unit for arcuate movement from an operative position substantially without the said first frame to an inoperative position substantially within the same.

4. In a stepladder, a reticulated main frame, a subframe having a reticulated, step riser end members having continuous peripheries except for a break therein in corresponding stepped portions thereof, said end members being adapted to be threaded into engagement with one section of said main frame through the breaks therein, and a step tread secured to and extending between said stepped portions to close the break in said end members and engage said sub-frame to said main frame.

5. A stepladder as in claim 4 wherein said end members have sharply recessed sections formed in corresponding portions thereof, and said recessed sections are adapted to be engaged with said main frame to lock said sub-frame in operative engagement therewith, said sub-frame requiring lifting thereof to be freed for movement to inoperative position.

6. A stepladder as in claim 4 wherein said end members have sharply recessed sections formed in corresponding portions thereof adjacent said step tread, said recessed sections are adapted to be engaged with said main frame to lock said sub-frame in operative engagement therewith and to have both frames directly supported on a common member, and said sub-frame is adapted to be pivoted up into said main frame and to abut on said main frame when in inoperative position and be retained in such position by gravity even though the stepladder is removed.

7. In a utility stepladder, a main frame unit, a step riser sub-frame unit, and means for pivotally securing said sub-frame unit to said main frame unit, said means comprising an arcuate slot formed in said sub-frame unit and a bar secured to said main frame and extending through said slot.

8. A lightweight utility stepladder comprising a pair of substantially inverted U-shape frames, open-centered reinforcing members for said frames, means securing said members to said frames at spaced vertical points intermediate the ends thereof to form a unit therewith, said members having corners formed therein with lugs formed thereon on the inside thereof adjacent said corners, said means including a wedge engaged with said lugs and forcing said members and frames together, an upper step secured to the upper of said members, a pair of lightweight substantially open step frames each of which defines a plane, a pair of steps secured to and extending between said step frames to form a unit therefrom, said step frames being threaded into engagement with one section of the lower of said members prior to attachment of said steps thereto, each of said step frames having an upwardly and forwardly directed elongate arcuate slot formed therein adjacent the rear thereof, a pivot bar extending through said slots and secured to said step frames to secure the unit formed thereof to said first frame unit for arcuate movement from an operative position substantially without the said first frame to an inoperative position substantially within same, and means for locking said step frame unit in operative position.

9. A lightweight utility stepladder comprising a pair of substantially inverted U-shape frames, open-centered reinforcing members for said frames, means securing said members to said frames at spaced vertical points intermediate the 15 10 said members having corners formed therein with lugs formed thereon on the inside thereof adjacent said corners, said means including a wedge engaged with said lugs and forcing said members and frames together, an upper step secured to the upper of said members, and step means pivotally secured to said frames.

ANTHONY F. GAUGHAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 52,211 Schmitt Jan. 23, 1866 897,929 Ridout Sept. 8, 1908 934,316 Jones Sept. 14, 1909 1,321,802 Beckwith Nov. 18, 1919 1,568,510 Kwasigroch Jan. 5, 1926 1,681,879 Putnam Aug. 21, 1928 1,946,747 Laborda Feb. 13, 1934 2,167,157 Muehlberg July 25, 1939 2,208,472 Richardson July 16, 1940 2,368,541 Griggs Jan. 30, 1945 2,392,584 Falkenstein Jan. 8, 1946 2,473,951 Hickey June 21, 1949 2,479,736 Fieroh Aug. 23, 1949

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