US1250279A - Ladder. - Google Patents

Description

A. J. CANFIELD.

LADDER. APPLICATION FILED SEPT- 18, I915.

Patented Dec. 18, 191?.

2 SHEETS -SHEET I.

A. J. CANFIELD.

LADDER.

APPLICATION FILED SEPT. 13. I916.

Patented Dec. 18-, 1917.

2 SHEETSSHEET 2.

UNITED sTArEs PATENT OFFICE.

ARTHUR J. CANIEIELI), OF CHICAGO, ILLINOIS, ASSIGNOR TO THE CANFIELD BROS. (30.,

OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

Application filed September 18,1916. Serial No. 120,611.

To all whom it may concern: I

Be it known that I, ARTHUR J. CANFIELD, citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Ladders, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention concerns ladders and, in its preferred embodiment,includes ladders having side rails formed of angle iron and rungs formed of rods andhas for one main object a new formation of the rungs and corresponding rung receiving openings or holes with the result that angle iron of standard formation may be employed for the side rails, and that the rungs may be formed by simple modification of the ends of short lengths of rods. The ladder rungs employed in this ladder of my invention do not project transversely of the ladder plane beyond the ladder rails. In making this preferred form of my invention, one wall of each side rail composing angle iron is placed parallel with the ladder plane while the remaining wall of each side rail composing angle iron is rovided "with an opening for each la der rung in which the adjacent end of said rung is received. At least one end, and preferably each end, of each ladder rung is provided with an inturned hook continuation preferably formed integrally with this ladder rung out of the same iron-rod that is preferably circular in cross section, the free end of such hook projecting inwardly and passing through or otherwise engaging the same wall of the sidev rail composing angle iron that receives the adjacent end of the ladder rung having this hook extension. By this construction the ladder rails and ladder rungs are maintained in proper relation. The ladder rungs are prevented from turning and are guarded from injury by the angle iron rails that project transversely of the ladder structure to the front and to the rear of the ladder rungs, the latter advantage being accompanied by the additional advantage that the ladder is no thicker or deeper than the ladder rails.-

In the preferred embodiment of the invention at least one, and preferably each,

ladder rail is inslidingrelation with the rungs passing therethrough whereby. a lad- Specification of Letters Patent.

Patented Dec. 18, 19 17.

der is. formed which is of particular utility when employed upon freight cars so that should the ladder receive a side or corner shock the rungs will not be damaged owing to the movability of the ladder rails along the ladder rungs or with respect to each other, it being also consequently true that the bending of one ladder rail will not be followed by the bending of the other and while each ladder rail is desirably in sliding relation with the rungs the invention is not to be limited to a construction in which either or both of the ladder rails have this relation to the rungs.

I will explain my invention more fully by reference tothe accompanying drawings showing the preferred embodiment thereof and in which Figure 1 is a plan view of a ladder constructed in accordance with the invention and mounted upon a freight car; Fig. 2 is a front elevation-of the ladder; Fig. 3 is a, sectional view on line 3 3 of Fig. 2; Fig. 4 is a view on a larger scale of a section of the ladder. with parts broken away; Fig. 5 is a view similar to Fig. 4 excepting that the construction illustrated in Fig. 5 is slightly modified; Fig. 6 illustrates a modification of the structure shown in Fig. 4; Figs. 7 8, 9 and 10 illustrate the process the ladder that is shown in Figs. 1 to 4 inclusive-and'Fig. 6; and Fig. 11 illustrates the process of assembling the form of ladder shown in Fig. 5 which is generally similar to the process illustrated in Figs. 7 to 10 inclusive.

Like parts are indicated by similar characters of reference throughout the different figures.

The ladder rails are desirably formed of angle iron, the angle iron walls 1 having circular openings or holes 2 that receive the ladder rungs 3. In the form of the inven tion shown in Figs. 1 to 4 inclusive and Fig. 6 each ladder rung is integrallycontinued at each end to form an inturned hook extension, the free end 4 of each hook extension passing through a circular opening or hole 5 in the wall 1 of the adjacent ladder rail. In the construction shown in Figs. 1 to 4 inclusive the ends 4 of the hooks provided upon each ladder rung are parallel with such rung and are desirably placed upon the same side thereof while the openings 2 and 5 receiving each rung structure permit sliding movement of the ladder rails longitudinally of and with respect to the ladder rungs so that either ladder rail may suffer violent blows that will move it toward the other ladder rail without injuring the ladder rungs or the other rail owing to the slid-7,.

ing relation of the ladder rails and rungs. The forniations upon the ends of the ladder rungs also function as braces to prevent the ladder rails from twisting out of their normal relation with each other and with the ladder rungs and also prevent the ladder rails from spreading apart. It is also apparent that the ladder rungs cannot turn upon their axes, an important consideration in all ladder construction. The hook ends 4 project inwardly nearly to the inner edges 6 of the angle iron walls 7, these hook ends being sufficiently long to prevent separation of the rungs from the rails in the event of inward bending of the ladder rails but being totally covered by the angle iron walls 7 (that are upon the front of the ladder) so that the clothing of the climber cannot be caught thereupon. The ladder rails may be mounted upon pedestals Or brackets 8 that may project from the side of a freight car or other mounting indicated at 9 and which brackets are desirably located at the ends of each ladder rail and at the middle thereof.

The form of the invention illustrated in Fig. is generally similar to the form of the invention hitherto specifically described, the inturned end 4 of one of the hooks upon each ladder rung 3 being omitted to form of the remaining portion of this book a mere head upon the ladder rung. the hooks that are minus these inturned ends guarding against the outward movement of the adjacent ladder rail, it being suliicient to have this hook limited to this function, while the remaining hook that retains the inturned end 4 notonly serves this function but also prevents the ladder rung having it from turning.

Where the ladder is to be made portable the form of construction shown in Fig. 6 may be employed wherein the inturned hook ends 4 are slightly bent out of parallelism with the ladder rungs whereby these hooks not only prevent spreading of the ladder rails but also prevent the approach of either ladder rail toward the other.

In making the ladder of my invention the ladder rungs are desirably shaped in a forming machine and are thereafter assembled with the ladder rails, the process of assembly of the structure shown in Figs. 1 to 6 inclusive'being illustrated in Figs. 7 to 11 inclusive with the exception that an initial step in forming the ladder illustrated in Fig. 5 may be omitted as indicated in Fig. 11, while in forming the ladder illustrated in Fig. 6 the inturned ends 4 are 65 bent in the direction of the rung 3 as a last step. In this assembling process the hooks upon the ladder rungs are initially inserted through the openings 2 with parts positioned in preparation for this step as indicated in Fig. 7 while the ladder rails are in an initially reverse position whereafter these ladder rails are moved along the hooks and on to the rungs to bring the lad der rungs within these holes, the ladder rails being moved sufliciently inward along the rungs (Fig. 8) .to permit the book ends 4 to be brought into alinement with the openings 5 (Fig. 9) whereafter the ladder rails are outwardly moved to cause the passage of the hook ends 4 through the openings 5 to complete the assembly of the rails and rungs (Fig. 10). In forming the ladder illustrated by Fig. 5 the process hitherto described is followed with, the exception that the partial hook at the right hand end is inserted in the corresponding hole 2 in the first instance, there being no extension 4 for this partial hook.

While I have herein shown and particularly described the preferred embodiment of my invention I do not wish to be limited to the precise details of construction shown as changes may readily be made without departing from the spirit of my invention, but having thus described my invention I claim as new and desire to secure by Letters Patent the following 1. A ladder including two side rails, rungs to which each ladder rail is slida'bl'y secured at all times and along which each 100 ladder rail may slide, and means upon the rungs for maintaining the ladder rails and rungs in assembly.

2. A ladder including two angle iro'n side rails each having rung receiving openings 105 in a wallthereof and other openings in the same wall adjacentthe former openings said openings being arranged substantially in a line parallel to the longitudinal edge of said wall, rungs received-in the first 11o openings and carrying hooks having inwardly extending ends which are received in the openings adjacent the rung rece ving openings.

3. A ladder including two angle iron side 115 rails, said rails having corresponding walls extending parallel with the plane of the ladder and inwardly toward each other, and their other corresponding walls extending transverse the ladder plane and 120 provided with rung-receiving openings and other openings adjacent the first openings in said last-named walls, and rungs received in the first openings and carrying hooks having inwardly extending ends that are received in the openings adjacent the rung receiving openings.

4. A ladder including two angle iron side rails each having entirely inclosed rung receiving openings in a wall thereof and other openings in said Wall adjacent the former; In Witness whereof, I hereunto subscribe rungs received and slidable in the first my name this 11th day of September A. D.

aforesaid openings and carrying hooks hav- 1916.

ing inwardly extending ends substantially ARTHUR J. CAN FIELD. parallel with the rungs and received and Witnesses: slidable in the openings adjacent the rung G. L. CRAGG,

receiving opening. ETTA L. lVHrrE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). C.

Images