US1148882A - Convertible ladder. - Google Patents

Description

M. M. WOOD. CONVERTIBLE LADDER. APPLICATION FILED MAR. 21. 1914.

Patented Aug. 3, 1915.

2 SHEETSSHEE'T I.

M. M. WOOD.

CONVERTIBLE LADDER. APPLICATION FILED MAR. 21. 1914.

Patented Aug. 3, 1915.

2 SHEETS-SHEET 2.

UNTTED TATE PATENT @FFTQE.

MILTON ivr. woon, or JACKSONVILLE, ILLINOIS.

CONVERTIBLE LADDER.

Application filed March 21, 1914.

To all whom it may concern: 7

Be it known that I, MILTON M. 7001), citizen of the United States, residing at Jacksonville, in the county of Morgan and State of Illinois, have invented certain new and useful Improvements in Convertible Ladders, of which the following is a specification.

My invention relates to new and useful improvements in ladders, and has for its principal object the provision of a ladder which may be employed as an ordinary step ladder, or may be quickly converted, by rearranging the relation of its parts, to form a wall ladder.

A further object is to construct a ladder which consists essentially in two freely connected legs, one of which is equipped with steps such as are ordinarily provided for the body portion of a step ladder, and the other of which is provided with rungs such as are used in connection with the ordinary type of wall ladder.

A still further object is to slidably and pivotally connect the two legs or sections of a ladder so that the leg having the rungs may be positioned to serve as a support for the other leg, when the ladder is used as a step ladder, or may be positioned so that it will extend in longitudinal alinement with the other leg, that is the leg having the steps, to forma continuation or extension thereof, adapting the ladder for use in reaching parts of a building or the like of considerable height.

Another object of the invention is to equip the step carrying sectionof the lad der with a pair of keeper plates which are so formed that they may either be engaged by latching hooks secured to the rung carrying section for freely maintaining this member against swinging movement, when the ladder is used as a step ladder, or will receive locking ribs carried by the rung section for holding this rung section against swinging movement, when it is extended to form a wall ladder in connection with the step carrying section.

An object of equal importance with the foregoing is to construct the ladder with such regard to number, proportion and arrangement of parts that it may be cheaply manufactured, will be durable and efiicient in its action, and may be easily and conveniently converted to serve either as a step ladder or a wall ladder.

Specification of Letters Patent.

Patented Aug. 3, 1915.

Serial No. 826,262.

The above and additional objects are accomplished by such means as are illustrated n the accompanying drawings, described In the following specification, and then more particularly pointed out in the claims, which are appended hereto and form a part of this application.

With reference to the drawings, wherein there has been illustrated the preferred em bodiment of this invention as it is reduced to practice, and throughout the several views of which similar reference numerals designate corresponding parts, Figure 1 a perspective View showing the rung and step sections set up to form a step ladder; Fig. 2 is a perspective view showing the step and rung sections longitudinally valined to form a wall ladder; Fig. 3 is a section on the line 3-3 of Fig. 1; Fig. a is a section on the line 1- of Fig. 3; Fig. 5 is a section on the line 5-.-5 of Fig. 2; Fig. 6 is a detail perspective view of the keeper plate; Fig. 7 is a detail perspective view of a latch which is used in holding the rung section of the ladder against sliding movement with respect to the step section while the ladder is being employed as a stepladder; Fig. 8 is a fragmentary sectional view particularly show ing the mounting of the latch member; and Fig. 9 is a fragmentary perspective view on a slightly enlarged scale showing the mounting of the brace rods for the steps of the body portion of the ladder.

The preferred embodiment of my invention, which is best illustrated in Figs. 1 and 2, consists in two freely connected sections 10 and 11, a pair of keeper plates 12 and 13, which are secured to the top step of the section 10, andco-act with hook plates 14: and 15in holding the two sections in propped relation, and also co-act with the locking ribs 16 in holding the two sections in extended relation, as in Fig. 2.

The section 10 as shown in the drawings consists in a pair of spaced legs or side members 17 and 18, which are connected by the steps 19. These steps 19 are relatively wide, so that the section 10 may be used as the body portion of the step ladder of the well known type. Screws or any other suit- I provided in connection with each of the step members 19 a brace rod, as indicated at 21. These members 21 are substantially identical in construction, one of them being illustrated in detail in Fig. 4, to which reference will now be had. It will be noted that each brace rod is provided at one terminal with a relatively long bar head 22, while its other terminal is threaded to receive a removable head, indicated at 24. This removable head includes a cylindrical internally threaded body member 24, and a transverse elongated bar head 25 which is formed integrally therewith.

The manner in which these brace rods are applied to the section 10 will be readily appreciated upon reference to Figs. 1 and 2, in

-which it will be seen that the cylindrical portions 24 of the movable heads are inserted through a longitudinally extending slot 26 formed in the side member 18 immediately below the steps 19. The rod 21 is then inserted through the slot 27 of the side member 17 and is threaded into the cylindrical portion 24 until the head members 22 and 25 have been drawn into severe engagement with the outer faces of the members 17 and 18. Y

It will thus be seen that the brace rods prevent the separation of the members 17 and 18, and, consequently, hold the terminals of the steps 19. against withdrawal from the receiving grooves formed in the inner faces of the members 17 and 18.

The side members 17 and 18, and all the steps 19, with the exception of the top step 28, may be formed of pine, spruce, or any other relatively cheap lumber, but it has been found expedient to construct the top step 28 of oak or some similar hard wood, inasmuch as this top step is subjected to considerable strain when the step sections 10 and 11 are in propped position, as in Fig. 1, or are extended as in Fig. 2.

A pair of substantially L-shaped metallic corner plates, indicated at .29 and 30, are applied to the inner faces of the upper corners of the side members 17 and 18 and the lower face of the top step 28. These corner plates are preferably formed of sheet metal, and are provided withdiagonal slots which register with diagonal slots 31 formed in the upper terminals of the members 17 and 18. As will be hereinafter explained, a rod 32, which is carried by the section 11 serves to a slidably and pivotally connect the two sec- 7 tions of the ladder, is received within these slots 31, and it is, therefore, desirable that some bracing means, such as the members 29 and 30, be attached to the members 17 and 18 of the section 10 to guard against the splitting of these members when the section 11 of the ladder is in extended position, as illustrated in Fig. 2. Screws, rivets, bolts or any other equivalent fastening devices,

indicated at 33, may be employed in attaching the corner plates 29 and 30.

The section 11 of the ladder, which will be hereinafter referred to as the rung section or ladder, consists in a pair of side members33 and 34, which are connected by the spaced rungs 35. These rungs 35 are of the ordinary type, and may be oak or some other hard wood, or if desired, may be constructed from metal tubes. The side members 33 and 34 of the section 11 are enlarged in width at their upper terminals for a purpose which will hereinafter become apparent. As above explained, a rod 32 is carried by the upper terminals of the side members 33 and 34, and is inserted through the slots 31 of the section 10. This rod 32 is of the usual construction, having a terminal head 36 which bears against the outer face of the side member 33, a nut 37 being threaded on opposite terminal of the rod and engaging against the outer face of the side member 34. It will be seen upon reference to Fig. 3 that the side members 33 and 34 of the section 11 are disposed to bear against the outer faces ofthe side members 17 and 18 of the section 10.

It now becomes apparent that it is necessary to provide some means for holding the step section 10 and rung section 11 of my ladder against relative movement when they are in position to produce a step ladder, as in Fig. 1, or are extended, as in Fig. 2, to provide a Wall ladder. For this purpose, therefore, there has been provided, as previously explained, the keeper members. 12

and 13, the hook plates 14 and 15, and locking ribs 16. The keeper plates 12 and 13 are similar in construction, and it is deemed necessary, therefore, to describe only one of them in detail. As illustrated in detail in Fig. 6, each keeper plate is formed in the nature of a metallic casting, including a body portion 38 which is substantially rectangular in shape and is bent at its rear terminal to form a downwardly extending lug 39. A pair of transversely extending spaced fingers 40 are formed on one longitudinal edge of the body member 38. These members 40 are apertured to receive rivets, screws or similar fastening devices, whereby the body plate may be held in position adjacent the terminals of the topstep 28, as in Fig. 1. It will also be noted upon refer ence to Fig. 8 that the lugs 39 engage against the rear edge of the top step 28. From the forward terminal of the body member 38 projects a hook member 42, the shank 43 of which extends laterally with respect to the body member, and the bill 44 of which is disposed in parallel spaced relationto the adjacent longitudinal edge of the body member. A notch or recess, indicated at 45, is formed in the longitudinal edge of the body member 38 at a point approximately opposite the bill 44 of the hook. These hook members 42 of the keeper plates 12 and 13 are adapted to be engaged by the hooks of the members 14 and 15, while the recesses or notches 45 are adapted to receive the locking ribs 16 when the rung section 11 is extended, as shown in Fig. 2.

Referring now particularly to Fig. 2, it will be seen that the members 14 and 15, which are substantially identical in construction, are in the nature of metallic castings and each includes a U-shaped body portion and a hook 46 formed at the intermediate portion thereof. The body portions of the members 14 and 15, each includes parallel side arms 47 and 48 which are positioned to. engageagainst the edges of the members 33 and 34, respectively, and a bight portion 49, which bears against the adjacent upper edge of each of said members. It will be seen that, if so desired, the members 14 and 15 may be formed of relatively heavy strips of sheet metal, and that the hooks 46 may be produced by bending the strips of metal upon themselves to form a doubled portion at the junction of the bight portions 49 with the side arms 47 and 48.

The manner in which the hook members 42 and 46 co-act in holding the step section 10 and rung section 11 against swinging movement when they are arranged in the form of a step ladder will be readily appreciated upon reference to Fig. 1. In this figure, it will be seen that when the members 10 and 11- are arranged to form a step, ladder the rod 32 is disposed in the upper ends of the slots 31, bearing against the horizontal portions of the corner plates 29 and 30, and that the hook members 46 engage the shanks 43 of the hooks 42.

When the user of the ladder desires to convert it from the step ladder, as shown in Fig. 1, for use as a wall ladder, as in Fig. 2, it is only necessary to swing the lower terminals of the step and rung sections toward each other so that the two sections will engage throughout their length. The two sections 10 and 11 are then slid one over the other in opposite directions to dispose the rod member 32 at a position adjacent the lower terminals of the slots 31. It then remains to swing the free terminals of the step and rung sections away from one another until the two sections of the ladder are in longitudinal alinement, as in Fig. 2. The two sections are then slid toward one another to dispose the rod 32 in the extreme lower terminals of the slots 32. When the rod 31 is thus disposed, the terminals of the locking ribs 16 are positioned in the notches 45 of the keeper members 12 and 13, as will be apparent when reference is had to Fig. 2.

The locking ribs 16 are similar in construction, each consisting in a metal strip the one terminal of which is enlarged as at 50 in Fig. 2. These ribs are secured with suitable fastening devices 51 to the inner faces of the side members 33 and 34 of the rung section 11, and are so positioned that, when the rung section is arranged to extend in longitudinal alinement with the step section, the enlarged terminals 50 will engage in the notches 45 of the keeper plates, and the registering recesses 52 which are formed in the terminals of the top step 28. It is also to be observed that a longitudinally extending channel or groove is formed in that step immediately below the top step 28, as indicated at 53 in Figs. 1 and 8. This channel or groove 53 is adapted to receive the rod 32 for an obvious purpose.

In order to prevent the sliding of the rod 32 through the slots 31 when the step and rung sections of my ladder are in folded relation, producing a step ladder as in Fig. 1, I have provided a catch 54 which is illustratedqin detail in Fig. 7. This catch is preferably formed of sheet metal, and consists in an arcuate body portion, one terminal of which is rolled, as at 55, to form a finger grip, and the other terminal of which is apertured, as at 56, to receive a ivot pin or other equivalent element, as at 5% in Fig. 3. A resilient finger, indicated at 58, is formed intermediate the length of the body portion of the catch, and is ofiset with respect thereto so that, while the body portion may be disposed between the rod 32 and the adjacent face of the top step 28, the operator may readily swing the catch to engage the finger 58 with the red, as in Fig. 3. As illustrated in Fig. 3, the finger member 58 is adapted to embrace the rod 32 when engaged therewith, and serves to hold the rod against the lower face of the top step 28, thus preventing sliding movement of the rung section 11 with respect to the step section 10.

In reduction to practice, it has been found that the form of this invention illustrated in the drawings, and referred to in the above description as the preferred embodiment, is the most eflicient and practical; vet realizing that the conditions concurrent with the adoption of this device will necessarily vary, it is desirable to emphasize the fact that various minor changes in details of construction, proportion and arrange ment of parts may be resorted to, when re- -flopiesot this patent maybe obtained for securing the two sections in longitudinal alinement to form a wall ladder.

2. A convertible ladder including a' step section having slots formed in its side members adjacent their upper terminals, a rung section, a rod extending transversely between the side members of the rung section and at the upper terminal thereof, said rod being mounted to extend throughthe slots of the step section, whereby the two sections are slidably and pivotally connected, a keeper plate carried by the step section, a hook member carried by the rung section and engageable with the keeper for holding the two sections in angular relation to form a step ladder, and locking ribs carried by the rung section and engageable with the keepers for holding the sections against swinging movement when they are longitudinally alined forming a wall ladder.

3. A convertible ladder including a step section, a rung section, a rod carried by the terminal of the rung section and slidably mounted in the terminal of the step section, whereby the two sections may be disposed at an angleto one another or may be longitudinally alined, a pair of keeper plates car ried by the step section, each of said keeper plates having a notch formed in its outer edge, and a hook member extending from the outer edge, a pair of hook members carriedby the rung section and engageable with the hooks ofthe keepers for holding the step section and rung section against swinging movement when they are angularly adjusted with respect to each other, and a pair of locking ribs carried by the rung section and engage'able in the notches of the keepers when the step and rung sectlons are longimes es tudinally alined, said locking ribs acting when engaged in the notches of the keeper plates to prevent the swinging of the sections with respect to each other.

4L A convertible ladder including astep section, a rung section, a rod carried by the terminal of the rung section and slidably mounted in theterminal of the step section, a pivoted member engageable with the rod for holding the same against sliding movement when the two sections are disposed in propped relation to each other, means for holding the sections against swinging move ment when the sections are in propped retion whereby the said locking ribs may be engaged with the saidkeeper plates when the sections are longitudinally alined. I

In testimony whereof I afiiX my'signature in presence of two witnesses.

MILTON M. WOOD. [L.S.] itnesses E. FQJOI-INSTON,

CI-rAs. HARMON.

five cents each, byaddres sing the Commissioner 01 Patents,

Wash1ngton,D.G.f

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