US1277504A - Extension-ladder. - Google Patents

Description

T. E. TANNER.

EXTENSION LADDER.

APPLICATION man NOV. 4. 1915.

2 SHEETS-SHEET l.

11 .1- ia j' fa INVENTOR WITNESSES I "Q 3 Z 13am?!- ATTO RN EY THOMAS E. TANNER, 0F SHERIDAN TOWNSHIP, MECOSTA COUNTY, MICHIGAN.

EXTENSION-LADDER.

To all whom it may concern:

Be it known that I, THOMAS E. TANNER, a subject of the King of Great Britain, residing at Sheridan township, in the county of Mecosta and State of Michigan, have invented certain new and useful Improvements in Extension-Ladders, of which the following is a specification.

This invention relates to certain new and useful improvements in an extension ladder and has for its primary object the provision of a plurality of connected sections which may be readily extended or locked in parallel relation, as desired.

Another object of the invention resides in the provision of a plurality of independent sections which are adapted to slide upon one another, and may be readily raised or' lowered or locked together.

A further object of the invention resides in the provision of new and improved guiding means.

For a further object, the invention con templates the provision of a simple connection between the various sections for moving the same longitudinally of one another.

For a still further object, the invention contemplates the provision of a plurality of sections provided with guide rods adapted to slide freely through the guide plates of an adjacent section and securely support the sections upon one another.

With these and other objects in view, as will appear as the nature of the invention is better understood, the same consists in the novel combination and arrangementof parts hereinafter more fully described, illustrated.

in the accompanying drawings and pointed out in the appended claims.

In the accompanying drawings forming a part of this application and in which like designating characters refer to corresponding parts throughout the several views,

Figure 1 is a side elevational view of the improved ladder parts being broken away to show one of the elevating cables or ropes.

Fig. 2 is a front elevation thereof.

Fig. 3 is a longitudinal section with the ladder in extended form, substantially on the plane of line 33 of Fig. 2.

Fig. 4 is an enlarged detail view of the means for locking together two of the sections.

Fig. 5 is a side elevation of the modified form of the invention.

Fig. 6 is a front elevation of the same, and

Specification of Letters Patent.

Application filed November 4, 1916.

Patented Sept. 3, 1918.

Serial No. 129,553.

Fig. 7 is a detail elevation of the lower portion of the device with the sections there of locked in their lowermost positions. Referring more particularly to the drawings, 1 designates the lower section and 2, 2 and2 the plurality of slidable sections carried by the main section 1. Suitable bearing members 3 are mounted upon the main section 1 to support the shaft 4; upon which the drum 5 is mounted. A crank or handle 6 is mounted upon one end of the shaft 4 for the purpose of rotating the drum 5 to wind the cables 7 upon the same or permit the cables 7 to unwind from said drum 5. The purpose of the cables 7 will presently appear. The shaft 4: also has mounted thereon, adjacent one end, a ratchet wheel 8, with which is engaged the pawl 9, pivoted to the supporting bracket 10 mounted upon one of the bearing members 3, previously mentioned. It will be readily seen that the pawl 9 will prevent rotation of the drum 5 in one direction and is preferably employed to prevent unwinding of the cables 7.

Each section of the ladder has outer side plates 11 secured upon its side members or uprights and upper and lower plates 12 and 13 secured upon the outer faces of the plates 11. The plates 12 and 13 have outwardly .drawn edges 14, through which are extended the guide rods 15, nuts 16 being secured upon the opposite extremities of said rods 15 and bearing against the outwardly turned edges 14 of the plates 12 and 13 to retain the rods in proper position. The lower plate 13, mounted upon each of the sections 2, 2 and 2* has a portion of its edge 14': extended to form a side ear 17, through which is slidably engaged the rod 15 of an adjacent section, preferably the next lower section. also be understood that the last or upper most section 2 does not require a guide rod but is guided by the rod 15 carried by the next section. The sections 2, :2 and 2 are furthermore guided by the guide straps 18 which have their opposite ends secured to one section of the ladder while the main. portions of said guide straps 18 are engaged around an adjacent section, preferably the next higher section. The straps 18 are located adjacent the upper ends of the sections by which they are carried, and it will be evident that it is not necessary to mount a guide strap 18 upon the uppermost section 2'.

Each section, with the exception of the It will "the lowermost ladder section.

21: has enlarged portions 23 engaged with corresponding portions 24 of the drum 5 to retard rotation ofthe latter. The cables 7 are then passed over the upper rollers or pulleys 19 carried by the lowermost section,'thc1i passed downwardly and extended around the lower rolleror pulley 20 of the first slidable or extension section, then brought upwardly and passed overthe upper roller or pulley 19 of this section and again extended downwardly for engagement around the lower roller or pulley 20 of the next section, and so on unt1l engaged over the last upper roller or pulley, 19. The cables 7 are then extended downwardly in the uppermost section 2 and secured in the bottom of the side inei'i'ibers of the same. It will therefore be seen that upon rotation of the dru1n'5 in one direction, the cables 7 will be wound around the same, forcing upwardly the extensions 2, 2 and 2 beginning with the uppermost section.

Inorder to securely lock the sections together as they are raised, I have provided a novel locking mechanism which will now be described in detail. A rock shaft 25 is mounted in the upper end of the section 2 and a pair of hooks 26 is mounted upon the shaft 25 for engagement with the lowermost rung 27 of the uppermost section 2 when the ladder is raised to its fully ex tended position, as shown in Fig. 3 of the drawings. Pivoted in an extended upper corner 28 of one of the hooks 26, is the upperend of the rod 29, the lower end of which is pivoted in a corresponding corner 30 of a hook 31, which latter is rigidly mouiitedupon the lowerrock shaft 32 carried by the lower end of said section 2 of the ladder. The free end of the hook 81 is extended in a direction opposite the corresponding ends of the hooks 26 however, for engagement with a rock shaft 33 mounted in the adjacent section 2 of the ladder to lock the section 2 in its lowermost position and prevent upward movement of the same dur-' ing operation of raising the uppermost sect'i o'n 2 The hook 31 is provided with a toii'g i'e' 34. on its l ower portion, however, by means of which said hook 31 as well as the hooks 26 may be moved inwardly or outwardly, as desired." By drawingoutwardly upon the tongue 34, the hook 31 may be withdrawn from the rock shaft .33 and the hooks 26 forced into engagement with the lowermost rung 27 of the raised uppermost extension section 2 thereby securely lockingthelast mentioned section in raised position and releasing the next section to permit raising of the same. It will therefore be seen that continued rotation of the drum 5 will result in raising thesection 2.

On the third section 2 carrying the rock shaft 33, I have positioned an upper rock shaft 35 and upoirthe upper rock shaft 35, I position a pair of hooks 36 which are adapted for engagement with the lowermost rung 37 of the second section 2 when the latter is in raised position, as shown in Fig. 30f the drawings. A connecting rod 38 has its upperend pivoted to an upper corner 'of one of the hooks 36 while its lower end is pivoted to an upper corner of the hook 39 carried by the lower rock shaft 33. The hook39 has its lower or curved end directed oppositelyto the corresponding ends of the hdoks 36 and adapted to engage the lower mostrung 49 of the lowermost or stationary section 1 of the ladder, when the third section is in its lowermost position and with its bottom on the same horizontal plane with the bottom of the stationary section 1. The hook 39 has a tongue extended from the same and by means of which said hook 39 and the hooks 36 may be noved in either direction. It will therefore be seen that after the second section has been raised, it willsimply be necessary to draw outwardly upon. the tongue 4-1 to release the book 39 from the rung i0 and engage the hooks 36 with the rung 37 of the second section, there by securely locking the second section in raised position and releasing the third section.

In. order to lock the third section in raised position, I have provided an upper rock shaft 42 and a lower rock shaft 43, both in the lowermost or stationary section 1, and

mounted a'pair of hooks 4e upon theupper rock shaft 42. forengagement with the lower nost rung 45 of the third section, when the latter is in raised position. One hook 44- has the upper end of the rod 46 pivoted v thereto, while the lower end of said rod 46 is pivoted to the operating member 47 on the rock shaft 43. Said member 47 has a tongue e8, means of which said member 47 and the hooks 44 may be caused to swing in either directionf It will therefore be seen that after. the third section has been raised, it will simply be necessary toldraw outwardly upon the tongue 48 to engage the hooks ie with said rung 45 and thereby lock the third section in raised position.

""lVlie'n it is desired to lower the sections, the pawl 9 should be thrown to inoperative position to permit unwinding of the cables 7. The tongue 48 may then be pressed inwardly, releasing the third section and permitting the same to move downwardly, the downward movement of said third section being controlled by means of the crank or handle 6. After the third section reaches its lowermost position, the tongue 11 may be pressed inwardly, releasing the second section and permitting downward movement of the same. In forcing inwardly the hook 39, said hook 39 should be securely connected with the lowermost rung 40 and the pivoted cam member 59 below the same, moved into engagementtherewith, preventing accidental movement of said hook 39 away from the rung 40. After the second section reaches its lowermost position, the tongue 34 may be pressed inwardly, thereby releasing the uppermost section 2 and at the same time locking the second section with the third section, by engagement of the hook 31 with the rock shaft 33. Below the upper end thereof, the side standards 01 the section 2 are connected by a transverse brace bar 49 which is adapted, with the ladder in collapsed position, to rest upon the upper end of the section 1. This bar serves as a stop between the sections 1 and 2 and also as a reinforcing means for the side standards of said section 2.

It is not necessary to provide any means for locking the uppermost section in its lowermost position.

As this ladder may be frequently employed upon the side of a building, I have pr vided a pair of rollers 50 in the upper end of the uppermost section 2", for engagement with the wall, so that the sections may be readily raised or lowered without danger of the uppermost section becoming caught upon an obstruction.

From the foregoing it will be clearly apparent that the sections may be locked or unlocked by the same party manipulating the crank or handle 6 without the necessity of ascending the ladder. It will also be noted that I have connected the side standards of each section by means of one or more bolts 50 upon which are mounted spacing sleeves 50 which serve to hold the standards spaced a suitable distance apart.

in Figs. 5 to 8 inclusive Ihave shown a modified form of the invention in which the principle is applied to a staff. In this form, each section.51"-5151 and 51 of the staff is formed of a pair of parallel side members 52 spaced at their upper and lower ends by the spacing blocks 53 positioned therebetween and held in place by the securing members 54 passed through the guides 55 secured upon the outer face of said sections 51, adjacent the opposite ends of the same. The purpose of the guides 55 will presently appear.

The lower end. the spacing block 53 positioned in the lowermost section 51, is extended below the same, as shown at 56, and adapted to be secured in an anchoring base to support the staff in upright position, as will be readily understood. It is not considered necessary to show the anchoring base in the drawings of this application.

A rear plate 57 is provided for closing the rear side of each staff section 51 and it will be apparent that the spacing blocks 53 serve to close the opposite ends of said staff sections 51 51, 51 and 51 The guide plates 55 have outwardly turned edges 58, within which are secured the guide rods 59 arranged upon opposite sides of the staff sections 51 51 51 and 51 one guide rod being provided upon each side of each of the staff sections with the exception of the first or uppermost section. It will also be apparent that upper guide plates for the first or uppermost section will be unnecessary. This section is provided with one of the lower guide plates 55, however, and each lower guide plate, with the exception of the one carried by the last or lowermost section 51, is provided with a forwardly extended perforated tongue 60,

through which one of the guide rods 59 is extended. The construction and connection of the sections 51 is the same on each side of the staff. Further connection and guiding means between the sections 51, 51 51 and 51 are provided by the employment of supporting and guiding loops 61, which are carried by the guide plates and engaged around the next higher section or the section riding upon the same, as will be readily understood. by referring to the drawings. It is to be remembered, however, that the loops 61. are only carried by the upper guide plates 55.

In order to lock the second and third sec tions, in their lowern'iost positions, I have provided the locking members 62 and which are pivoted respectively upon the guide rods 59 carried by the third section and the fourth or stationary section and upon one side of the same. The locking members 62 and 63 have bent tongues 64- and 65 respectively, for engagement over the turned edges of the lower guide plates 55 carried by the second and third sections 51, when said locking members 62 and 63 are in looking position to hold the staff sec tions in their lowermost positions.

The means for raising the sections of the staff and controlling downward movement of said sections 51*, 51 51 and 51", includes a drum 66 carried by the shaft 67, which lat ter is mounted inthe outwardly directed parallel ends 68 of the bracket plates 69, the opposite ends 70 of which are offset and secured between the side members 52 of the last or lowermost section 51*. One end of th sha 6. i extend d; and provid d wi h a crank or handle 71, by means of which the shaft 67 and drum 66 may be readily rotated to wind thereon the cable 72, which latter has one end secured to said drum 66. The extended end. of the shaft 67 also has a ratchet wheel 7 3 mounted thereon and a pawl 7 1 is pivoted to a supporting ear 75 carried by one of the bracket plates 69. The pawl 7 1 is of conventional form and has its working end normally el'lgaged with the teeth of the ratchet wheel 73, while the opposite end or weighted end of said pawl 74 is curved so as to extend over the ratchet wheel 73, and beyond the pivot point of the pawl, thereby overbalancing the working end of the pawl and causing the same to antomatically engage with the teeth of the ratchet wheel 7 8, as the latter is rotated beneath the same.

A guide pulley 76 is mounted in the upper end of the last or lowermost section 51 while guide pulleys 77 are mounted in both the upper and lower ends of the second and third sections and the remaining or upper end of the cable 72 is secured in the lower end of the first or uppermost section 51 after being passed over the pulleys 76 and 77. It will be understood that in passing the cable 72 from the drum 66 to the lower end of the first or uppermost staff section 51 the cable is first passed over the pulley 76, then extended downwardly around the lower pulley 77 in the third section 51, brought upwardly over the upper pulley 77 in said third section, then extended into the second section 51, around the lower pulley 77 in the same, extended upwardly over the upper pulley in said second section and into the first or uppermost section, within which first or uppermost section 51, the end of the cable is extended downwardly and fastened in the lower spacing block 53 thereof, as indicated in the drawings.

From the foregoing, it will be understood that the sections are normally locked in their lowermost positions, with the exception of the first or uppermost section, which will readily rise upon rotation of the drum 66 in the proper direction. Upon further rotation of the drum 66 in this direction, the other movable sections may be readily raised, after unlocking or releasing of'the same and the pawl 7 a will prevent unwinding of the cable 72. Vl hen it is desired to lower the sections, however, the pawl 74 is moved to inoperative position, thereby permitting a free rotation of the drum 66 and unwinding of the cable 72 therefrom. Downward movement of the staff sections may be controlled,

nevertheless, by means of the crank or handle 71. It will also be evident that the locking members 62 and .63 may be controlled by the same party operating the crank or handle 71 This staff'may be employed as a flag staff, or signal staff and secured in a stationary support, if desired, or may be employed for supporting wireless signaling apparatus and mounted upon a motor vehicle or other movable member. In fact, the uses to which this form of staff is adapted, may be said to be practically unlimited.

It is believed that the invention may now be thoroughly understood and further description of the same is unnecessary.

While the form of the'invention shown and described is what is believed to be the preferred embodiment thereof, it is nevertheless to be understood that minor changes therein in the details of construction and arrangement of parts may be made within the scope of the appended claims, without departing from the spirit of the invention.

I claim 1. An extension ladder, comprising a plurality of relatively slidable sections, side plates secured to the side standards of said sections in spaced relation to their outer faces, and extending the full length thereof, pulleys mounted between the side plates and standards of certain of said sections, a drum carried by the base section of the ladder, cables attached at one end to said drum, and having their opposite ends trained. over said pulleys and secured to the upper end section of the ladder, plates mounted upon the upper and lower ends of certain of said side plates and extending outwardly therefrom, a lower guide plate mounted upon said upper endsection, said lower plates being extended to overlap one another, and a plurality of guide rods passing through said upper plates and through the overlapping portions of said'lower plates.

2. An extension ladder comprising a ground section, a plurality of relatively slidable sections supported by the said ground section, means for elevating said sections, means carried by certain of said sections to hold the next higher section in elevated position, and means for releasing said holding means to permit lowering of said sections, the said releasing means of certain of the said sections being adapted for locking engagement with the next lower sections when all of said sections are in lowered position.

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

THOMAS E. TANNER.

Witnesses:

ADELBERT MYERS, FRANK WILSON.

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

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