US570939A

US570939A - Extension-ladder

Info

Publication number: US570939A
Authority: US
Publication date: 1896-11-10
Anticipated expiration: 1913-11-10

Description

(No Model.) 7 i a Sheets-Sheet 1.

J. F. MACK.

I EXTENSION LADDER.

N0. 5'70,939. Patented Nov. '10; 189613 J; P. MAOK.

EXTENSION LADDER.

3 Sheets 8heet 2.

(No Model.)

Patented Nov. 10, 1896.,

N5 Model.)

' 3 Sheets-Sheet 3. J. F. MACK. EXTENSION LADDER. NO. 570,939.

Patented Nov. 10, 1896.

UNITED STATES PATENT OFFICE.

JOHN F. MACK, OF LITTLE VALLEY, NEW YORK.

EXTENSION-LADDER.

SPECIFICATION forming part of Letters Patent No. 570,939, dated November 10, 1896.

Application filed June 25, 1895. Serial No. 554,007. (No model.)

To all whmn it may concern.-

Be it known that I, JOHN F. MACK, a citizen of the United States, residing at Little Valley,in the county of Cattaraugus and State of New York, have invented a new and useful Extension-Ladder, of which the following is a specification.

This invention relates to extension-ladders to be used when it is required to reach an elevated point and which are chiefly designed for service in connection with life-saving apparatus usually provided as a part of the equipment of the fire department of a city or town, and has for its obj ect to provide a structure which will be light and simple in its organization and which will admit of the ladder-sections being quickly extended for use and folded into a compact form when the device is not in use, and which at the same time will admit of the ladder when extended being moved to any required position and firmly braced after being properly adjusted.

A further object of the invention is to combine with the ladder a basket or car and means for raising and lowering the same, whereby persons can be readily reached from any window or opening in a burning building and lowered to the ground in safety, and to combine with said car or basket provisions for steadying the same when at its highest position, so that a person may enter the car or basket without the dangers attendant upon this class of devices Where the car is permitted to sway by hanging pendent from the end of the hoisting-rope.

A still further purpose of the invention is the provision of novel means whereby the ladder-sections can be raised and lowered from the ground and held at the required point of extension, the said sections being moved successively and the section reaching the limit of its projection being locked and automatically freed from the actuating mechanism, which immediately is thrown in gear with the next ladder-section of the series, so as to move it to the required limit.

The improvement consists of the novel features and the peculiar construction and combination of the parts, which hereinafter will be more fully described and claimed, and

which are illustrated in the accompanying drawings, in which- Figure l is a perspective View of the improved ladder, showing it extended. Fig. 2 is a sideelevation of the same, showing it reduced to a compact form and supplied with a forward truck. Fig. 3 is a detail view showing the relative disposition of the parts when the first movable ladder-section is at the limit of its upward movement and the actuating mechanism is in gear for extending the next or second movable section. Fig. 4 is a crossthe axle. Fig. 8 is a detail view of one of the extension-braces. Fig. 9 is-a detail View of a rung.

The ladder may be composed of any required number of sections, according to the height to which it may be required to extend the same, and, as shown, itis formed of three

sections

1, 2, and 3, which are so related as to slide the one upon the other, and these sections are of graduated widths, so that they will nest together and enable the parts to occupy a minimum amount of space when the structure is reduced to a compact form. The side bars of the sections may be of wood or metal, wood being preferred for the sake of lightness and cheapness of construction. The side bars of the sections 2and 3 will have metal plates 4 secured to their lower edges,and the outer edge portions of these plates twill extend beyond the sides of their respective bars and operate in guideways 5, provided on the inner sides of the side bars of the

respective sections

1 and 2, said guideways being formed between the opposing sides of metal strips 6 and 7 secured, respectively, to

the top edges and inner faces of the side bars of the said sections 1 and'fZ. The metal strips 7 are L-shaped in cross-section, and are secured in any suitable manner to the inner faces of the side bars, and the flat metal strips 6 are firmly attached in any approved manner to the edge portions of the said side bars. Any well-known means may be substituted for the parts at, 6, and 7 to guide the ladder-sections intheir movements and maintain them in a fixed relative position at any pointin their movement. The rungs 8 are preferably tubular and have their ends 9 flanged and fastened by rivets to the side bars, thereby resulting in further lightening the structure and providing a ladder of exceeding strength, inasmuch as the side bars are not perforated for the passage of the ends of the rungs, as usuallypracticed in the construction of ladders for general use.

The ladder will be supported upon

trucks

10 and 11, which may be of any suitable construction to facilitate the transportation of the device to the required point for using. The front truck 10 is detachably connected in any desired manner, so as to facilitate the extension of the ladder when required. The rear truck is a permanent part of the device, and comprises an axle 12, mounted in bearings 13, made fast to the side bars of the section 1, and supporting-Wheels 14, loosely journaled upon the spindles of the axle 12. A locking-lever is mounted upon the outer end of the axle and is provided on its outer face with a cam-surface 16, which is adapted to engage with the ordinary axle-nut 17 and secure the supporting-wheel in locked relation upon its axle. It will be understood that each wheel 14: will be supplied with a locking-lever 15, so that after the ladder has been properly positioned the wheels can be secured from turning upon their respective axles.

A hand-wheel 18, sprocket-wheel 19, and toothed wheel 20 are secured together, so as to revolve as annit, and are mounted upon' one end of the axle 12 inside of the adjacent supporting-wheel 14. Ashaft 21 is journaled in the side bars of the section 1 in proximate relation to the front or upper ends thereof, and this shaft has a sprocket-wheel 22 keyed thereto upon its projecting end and around which passes a sprocket-chain 23, by means of which motion is transmitted from the sprocket-wheel 19 to the said sprocket-wheel 22 and the shaft 21. Pinions 24c are placed upon the shaft 21 and are adapted to mesh with rackbars 25, secured to the side bars of the section 2, so that in the rotation of the shaft 21 the section 2 will be moved upon the section 1, so as to be extended or folded as required. A pinion 26 is keyed to the projecting end of the shaft 21 and is adapted to mesh with a corresponding pinion 27 on the end of the shaft 28, journaled in the side bars of the section 2 near to its rear or lower end. A sprocket-wheel 29 is mounted upon the opposite end of the shaft 28 and supports the lower end of a sprocket-chain 30, which is supported at its upper end by means of a sprocket-wheel 31 on the projecting end of a section 2 near to their upper ends, and this shaft 32 is supplied with pinions 33, which are adapted to mesh with rack-bars' 34, secured to the side bars of the section 3.

The operation of extending the ladderis as follows: On rotating the hand-wheel 18 in the proper direction the sprocket-wheel 19 will be correspondingly actuated and drive the sprocket-chain 23 and effect a rotation of the shaft 21 in the manner set forth, and by means of the pinions 24 meshing with the rack-bars 25 the ladder-section 2 will be extended, and when it reaches the limit of its upward movement the rack-bars 25 will become disengaged from the pinions 24 and the

pinions

26 and 27 will gear, and a further rotation of the shaft 21 will, through the

meshing pinions

26 and 27, drive the shaft 28 and cause a movement of the shaft 32 through the gearing previously described, and the pinions 33 on the shaft 32 meshing with the rack-bars 34 will result in an extension of the section 3. It will be understood that where more than two movable sections are employed the parts will be related substantially in the manner set forth herein, so that after one section has been extended to its utmost limit its extending mechanism will be thrown out of operative relation and the provisions for operating the next section of the series will be thrown in gear, so that in the further operation of the extending mechanism the said section to be extended will be operated in the manner set forth, as will be readily comprehended.

In order to support the section extended to its utmost limit and maintain the

pinions

26 and 27 in meshing relation, a supporting c011- trivance has been devised to positivelyengage with and sustain the said section in its extended position. These provisions consist of a rock-shaft 35, journaled in blocks 36, provided on the inner faces of the side bars of the section 1 and having short arms 37 near its ends to be projected across the path of the side bars of the section 2, and having an intermediate arm 38, which is connected by means of a rod or wire 39 with an operating-lever 40, pivoted at one end to a rung of the section 1 and extending within convenient reach from the ground. Catches 41, of any desired construction, are provided and suitably disposed to engage with the free end of the lever 40 and hold the latter in either of its extreme positions. After the section 2 has been extended the lever 40 is operated and results in turning the rock-shaft 35 in its bearings and projecting the arms 37 in the rear of the side bars of the section 2, and if the

pinions

26 and 27 are not fullyin mesh the engagement of the arms 37 with the lower ends of the side bars of the section 2 will effect an upward movement of the said section 2, so as to bring the

pinions

26 and 27 completely and opera tively in mesh and throw the pinions 2i and shaft 32, journaled in the side bars of the rack-bars fully out of engagement, so that the parts may operate successfully in the manner designed.

A lever 42 is provided and adapted to engage with the toothed wheel 20, so as to secure the latter from further rotation in either direction after the ladder has been properly extended, and this lever 42 is elbow-shaped and is fulcrum'ed at the elbow and has one member terminating in a bent end to engage with the teeth of the wheel 20, and its opposite end extending within convenient reach to be grasped and operated when required.

A bracket 43 is located at the upper end of the topmost section and is sufficiently broad to provide a foot-rest to assist in the safe alighting of a person from the ladder into the basket or car 44, and the outer end of this bracket is formed with a tubular guide 45. and

provided with a pulley 46, over which the hoisting-rope 47 passes, by means of which the basket or car 44 is raised and lowered. The basket or car 44 may be of any desired construction and is a light framework of wirenetting, and is provided with a vertical rod '48, centrally disposed and to which the hoisting-rope 47 is attached. This vertically-extending rod 48 is adapted to enter the tubular guide 45, by means of which the car or basket is steadied, so as to prevent any swaying movements of the said basket or car and to obviate the disastrous results frequently occurring by reason of the swaying of the basket when a person is attempting to enter the same. A drum 49 is loosely mounted upon the end of the axle 12, opposite to that provided with the

parts

18, 19, and 20, and it is provided with a hand-wheel 50, by means of which it is rotated to wind up the hoistingrope 47, and with a toothed wheel 51, which is adapted to be engaged by a lever 52, similar in construction and for a like purpose to the lever 42. A brake-band 53 is supported at one end by having attachment to a block or the side bar of the section 1, and after passing half-way around a head of the drum 49 is engaged at its opposite end with the end of a lever 54, by means of which the brake-band can be pressed closely against the peripheral edge of the drumhead'49, so as to regulate the paying out of the hoisting-rope 47 in the descent of the basket or car 44.

Levers 55 are pivotally attached to the lower or rear ends of the side bars of the section 1 and are provided with the usual handlatches 56 to engage with notched segments 57, by means of which the said levers are held in the required located position, and

these levers are adapted to facilitate the erection of the ladder and the steadying and bracing of the same afterbeing raised to the required position.

The braces 58 for sustaining the ladder after it has been extended are pivotally supported or connected at their upper ends to the side bars of the section 1, and, as shown, are secured to the ends of a rod 59, journaled in brackets 60, attached to the said side bars and stays 61 between the said rod and the braces 58 to hold the latter from outward displacement. These braces 58 are extensible and comprise the

sections

62 and 63, the upper sections 62 having a series of teeth 64, which are engaged by dogs 65, pivoted to the lower sections 63, and which dogs are operated by hand-levers 66, having connection therewith by rods 67, operating in guides 68, formed on the said sections 63. Springs 69 are provided and mounted upon the rods 67, so as to hold the dogs in engagement with the teeth 64. The sections 63 have lateral extensions 70, which are bent to embrace the edge portions of the sections 62 and by means of which the two sections are held in operative relation.

It will be seen from what has been said that the construction is simple and easy of manipulation, also that the parts are readily accessible, and that the ladder can be used wherever it is required to reach an elevated point. The manner of operation is perfectly obvious from the foregoing detailed description, and many objects and advantages not set forth herein are obvious, and it is to be understood that in the embodiment of the invention to meet the various needs changes in the form, proportion, and the minor details of construction may be resorted to without departing from the principle or sacrificing any of the advantages of this invention.

The braces 58 are supported in a folded position by means of hooks or catches 71, made fast at their upper ends to the side bars pf the section 1, as most clearly indicated in Having thus described the invention, what is claimed as new is 1. An extensible ladder comprising aseries of sections, actuating mechanism for extending the sections, and comprising pinions disposed at opposite ends of adjacent sections and brought together when the said sections are I extended, a cross-shaft provided with short arms to engage with the section after it has been extended, and a lever operatively connected with the said shaft to turn the same, whereby its short arms are brought in positive engagement with the said extended ladder-section to move the latter up to insure the engagement of the said pinions and maintain them in meshing relation, substantially as set forth.

2. In combination, slidable ladd er-sections, actuating mechanism comprising a rack and pinion for moving the first adjustable section .of the series and for carrying the same be yond its operating mechanism when fully extended, a rack and pinion for the second ad justable ladder-section of the series brought into gear with the said actuating mechanism, and means for elevating and supporting the first adjustable ladder-section when moved to a point beyond its actuating mechanism and at the same time bringing the second adjustable ladder-section in gear with the actuating mechanism and maintaining the parts in operative relation, substantially as set forth.

3. In combination, a series of slidable ladder-sections, the first section provided with a shaft near its upper end having a pinion, the.

next section having a shaft provided with a corresponding pinion at its lower end, and means for elevating or extending the movable section and throwing its operating mechanism out of gear when the said section is fully extended and bringing the said pinions into mesh, substantially as set forth.

4. In an extensible ladder, the combination with a bracket provided with a guide, of a basket, or car, having rigidly secured thereto a Vertical rod to engage with the said guide and hold the car, or basket, in a fixed relative position when elevated, substantially as set forth.

5. In combination, an extensible ladder, a bracket secured to the upper end thereof and provided with a pulley and a guide, a basket having a vertically-extending rod adapted to enter and cooperate with the said guide, a hoisting-rope, a drum provided with means for its rotation, a toothed wheel having connection with the drum, a lever to engage with the toothed wheel to hold the drum against rotation in either direction, and a band-brake adapted to be applied to a head of the drum to control the speed of the latter during the descent of the basket, substantially as described.

6. In combination, a series of ladder-sections slidably related, the relatively-movable sections provided with rack-bars, shafts journaled in the opposite ends of the sections and provided wit-h pinions to mesh with the rackbars, by means of which the said sections are extended, pinions on the shafts of adjacent sections and adapted to be brought into mesh when said sections are relatively extended to the limit of their movement, and a support adapted to be engaged with the section and hold it at the limit of its upward movement and maintain the said pinions in meshing relation and the operating mechanism out of gear, substantially as setforth.

In testimony that I claim the foregoing as my own I have hereto aflixed my signature in the presence of two witnesses.

JOHN F. MACK.

IVitnesses:

F. McMERRILL, A. C. STEPHENS.