US1139996A - Movable extension-ladder. - Google Patents

Description

G. PREDONZAN.

MOVABLE EXTENSION LADDER.

APPLICATION FILED 05c. 26. 1912.

1,139,996 Patented May 18, 1915.

a SHEETS-SHEET 1.

THE NORRIS PETERS CO-. PHOTO-LITHO.. WAEHINGTUN. D C.

G. PREDONZAN.

MOVABLE EXTENSION LADDER.

APPLICATION FILED DEC. 26, I912.

1 1 39,996 Patented May 18, 1915.

6 SHEETSSHEET 2.

v o 4K "U 5 1 I .59 46H 6/ Zll I?? Q 1 f I 43 u l :r :II III: lc d lx /1u ur THE NORRIS PETERS CO4, PHOTD-LITHO, WA5HlNGTON.-D. C.

G. PREDONZAN. MOVABLE EXTENSION LADDER.

APPLICATION FILED DEC. 26, 1912.

- Patent-ed May18; 1915.

6 SHEETS-SHEET 3.

THE NORRIS PETERS 50.. PHOmUTHQ. WASHINGYUN. L.

e. PREDONZAN.

MGVABLE EXTENSION LADDER.

APPLICATION FlL-EI) 05c. 26. 1912.

Patented May 18, 1915.

6 SHEETS-SHEET 4.

THE NORRIS PETERS ca, FHom-LITHQ. WASHINGTON. p c.

G. PREDONZAN.

MOVABLE EXTENSION LADDER. I

APPLICATION FILED DEC. 26, I9I2.

Patented May 18, 1915.

6 SHEETS-SHEET 5.

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THEJVORRIS PETERS 00.. FHOWLITHOH WASHINGTON. D. G

e. PREDONZAN.

MOVABLE EXTENSION LADDER.

APPLICAHON HLED DEC. 26, 19 12. 1 ,139,996. Patented May18, 1915.

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THE NORRIS PETERS 60., PHOTO-LITHQ, WASHINGTON, D4 6 GIOVANNI PREDONZAN, 0F TRIESTE', AUSTRIA-HUNGARY.

MOVABLE EXTENSION-LADDER.

Specification of Letters Patent.

Application filed December 26, 1912. Serial No. 738,662.

To all whom it may concern:

Be it known that I, GIOVANNI PREDoNzAN, a subject of the Emperor of Austria-Hungary, and resident of Trieste, Austria-Hungary, have invented a new and useful Improvement in Movable Extension-Ladders, of which the following is a specification.

This invention relates to a movable extension ladder and is adapted chiefly for use as part of a fire fighting apparatus.

An object of this invention is to provide an arrangement of this character which may be extended to a very great relative length in proportion to its size when collapsed, and which is extremely light for its strength.

Another object is to provide a ladder of this character which may be extended at any angle'from the horizontal to the vertical, and which may also be swung into any desired angle in a horizontal plane.

Another object is to provide such an apparatus which may be very quickly brought into operative position and maneuvered by a single individual.

Another object is to provide meansfor rapidly and simultaneously extending or projecting all sections of the ladder Another object is to provide a life saving attachment in connection with the ladder by which persons maybe transported from the upper floors of buildings'to the ground without the necessity of their being carried down the ladder, and in which the rate of descent may be regulated by an operator near the bottom'of the ladder. A still further object is to provide certai improvements in the construction, form and arrangement ofthe various parts, whereby the above-mentioned objects may be effectively carried out.

A practical embodiment of this invention is represented in the accompanying drawings, in which Figure 1 represents a partial side View of the complete apparatus with'the ladder in collapsed position, Fig. 2 represents a view similar to Fig. 1 showing the remaining portions of the ladder, Fig. 3 represents a partial side elevation of the complete apparatus with the ladder in extended position, Fig. 4 represents a view similar to Fig. 3 showing the remainder of the ladder and life saving apparatus, Fig; 5 represents a detail side view of the apparatus, part of the casing being removed to show the mechanism within, Fig. 6 represents an end Patented May 18, 1915 View of the casing and adjacent parts,'one

side of the casing being removed to show the mechanism within, Fig. 7 represents'an end view of the casing and ladders thereupon, taken in a direction opposite to Fig. 6, part of the casing being removed for showing the mechanism within, Fig. 8 rep resents a horizontal section taken in the plane of the line AA of Fig. 5, looking in the direction of the arrows, Fig. 9 represents a detail plan view showing the connection between the sections of the ladder for moving the same, Fig. 10 represents a detail section, showing the clutch .mechanism used in connection with operating the ladder, Fig. 11 represents a detail elevation, showing the meansfor securing the sections of the ladder in extended position, Fig. '12 represents a detail elevation of the means for locking the sections to the ladders in extended position, taken at right angles to Fig. 11, Figs. 13, 14:, 15, represent detail side elevations showing various positions of the levers and connecting rods for locking the sections of the ladder and the brace therefor, and releasing the same, and Fig. 16 represents a detail view showing the means of securing the ladder. extending ca bles carried by the second section of the ladder to the first section.-

The apparatus includes a suitable truck.

denoted by 1 upon which is fixedly mounted a stanchion 2 which may conveniently be composed of angle iron uprights and strap iron diagonal braces, as clearly shownin the drawings This stanchionEZis mounted I about centrally of the truck 1 in a base 3,

and is provided at. its upper end with a cap A having a' centrally disposed bearing pin 5 extending upwardly therefrom and rigidly secured in position by a nut 6.

A rectangular casing 7, composed of ironor other convenient materlal, has a central opening'8 in the bottom thereof, while its upper end-1s closed by a strong top 9 rigidly secured thereto. This top 9 is'pro vided on its underside with a centrally disposed socket 10 in which is secured a bearing plate 11, fitted to rest upon the pin 5 for pivotally supporting the casing 7, and

theparts itcarries, upon the stanchion 2.

A platform 12 is centrally-pivoted at 13 on one upper edge of the top 9 of the casing 7 for swinging in a vertical plane upon the said pivot. The said platform 12 has a pair of .suitable right angularly projecting struts 14 mounted. thereon about intermediate its ends, over which are passed a pair of stays 15 fixedly secured at each end of the said platform 12, whereby the plat form is strongly braced against bending or breaking in its plane.

The extension ladder, shown in the present instance, consists of three sections '16, 17 and 18; the lower section 16 being pivoted intermediate its ends by a pivot 19 located in the end of the platform 12 which is arranged to be the upper end of the said platform when it is swung in a vertical plane about its pivot 13 on the top 9.

Each of the sections 16, 17, 18, of the ladder are of substantially the same length, but the section 17 is sufficiently narrower than the section 16 so as to readily slide longitudinally thereon between the side members thereof; and the section 18 is correspondingly narrower than the section 17 for the same purpose.

The section 16 is provided with a plurality of right angularly extending struts 20 located at each side thereof intermediate the ends, and adapted to support stays 21 fixedly secured in the ends of the side members 22 for reinforcing the section 16 in its plane.

The section 17 has its struts 23 and stays 24 secured to the side members 25 for a corresponding purpose; while the section 18 is. similarly provided with its struts 26 and stays 27 mounted on its side members 28. The struts carry guide rollers 18* for holding the ladder sections parallel.

The casing 7 and its attendant parts may be swung on the pivot pin 5 for the purpose of leveling the apparatus as a whole, in case the truck 1 is resting on uneven ground, by means of the arms 29 (see Fig. 8) pivoted at 30 in an arc piece 31 secured on a drum 32 which is fixedly mounted on the stanchion 2 near the lower end thereof. The other ends of the arms 29 are pivoted on pins 33 in the side of the casing 7; and a swinging movement of the casing 7 on the pin 5 is obtained by operating the screw 34 mounted in the casing 7 at right angles to the arms 29, with which arms it has a screw threaded engagement by means of lugs 35 swiveled in the arms 29 and extending upwardly from the said arms. This screw 34 may be rotated by means of the crank 36 fitted onto the squared end of the said screw 34 exterior to the casing 7 he operation of this screw 34 will carry both arms 29 in the same direction and will positively force the casing 7 and parts carried thereby to swing in one direction or the other with respect to the stanchion 2.

The casing 7 and its attendant parts may be manually rotated on the pin 5 for the purpose of projecting the ladder in different directions in a horizontal plane, and a brake is provided for securing the said casing in rotary position with respect to the stanchion 2, which brake consists of two cables 37 (see Fig. 5) fixedly secured at 38 in one side of the casing 7; the other ends of the said cables 37 being secured in the T-head 39 of a lever 40 secured against rotation on one end of a shaft 41 horizontally journaled in a lug 42 mounted on the side of the casing 7. This shaft 41 extends without the casing and is provided with a handle 43 fitted on the exterior end thereof for rotating the said shaft 41. It will be readily observed that by rotating the shaft 41 in one direction, it will swing the lever 40 so as to constrict the cables 37 about the drum 32 and hence secure the casing 7 and its appurtenances in any desired rotary position about the stanchion 2. The reverse movement of the handle 43 will, of course,

'slacken the cables 37 and permit the casing 7 to be free to rotate.

The means for swinging the platform 12 about the pivot 13 consists of a pair of drums 44 secured against rotation on ashaft 45 mounted horizontally in the casing 7 at right angles to the platform 12 and having its ends extending without the casing 7 and provided with crank handles 46 for manual operation thereof.

A pair of'cables 47 have one end secured at the pivot 19;. thence pass around the drums 44, around which the cables are wound one or more times; and they then pass under pulleys 48 secured near one lower corner of the casing 7 and extend to that end of the platform 12 which will be the lower end when the platform is swung out of a horizontal position, to which end they are fixedly secured, as indicated at 49. By turning the crank handle 46 it will be evident that the drums 44 will be rotated, thereby winding or unwinding the cables 47 thereupon, and hence swinging the platform 12 and the parts supported thereby in one direction or another in a vertical plane about the pivot 13.

A pawl 50 is pivoted at 51 and arranged to engage a ratchet wheel 52 fixedly secured on one of the drums 44 for preventing the unintentional unwinding of the cables 47 on the drums 44.

A small lever 53 is located in the casing 7 with its handle 54 exterior thereto for holding the pawl 50 out of engagement with the ratchet '52 when it is desired to rotate the drums 44 for unwinding the cables therefrom.

Mechanism is provided for extending the sections 16, 17, 18, of the ladder, which is arranged as follows: Large drums 55 are loosely mounted on the shaft 45, each of which drums carries a gear 56 arranged in engagement with pinion 57 secured against rotation on shafts 58, 59, which i shafts are provided with crank handles 60, 61, respectively.

A pair of endless cables 62 pass once or more around. the large drums 55; thence around pulleys 63 mounted in the upper corner of the casing 7; thence around pulleys 64 mounted on the pivot 19 on the section 16 of the ladder and thence in a loop around pulleys 65 and 66 at opposite ends of the said section of the ladder, the said loops 61, the shaft 58 will be rotated thereby rotating the pinions 57 which mesh with gear wheels 56 and hence cause the large drums 55 to rotate on the shaft 45.

This movement of the large drums 55 will actuate the cables 62, and, by reason of the fixed engagement of one part of the said cable at 67 on the section 17 of the ladder, the said section will be caused to slide longitudinallyupward or outward on the section 16. This movement of the section 17 will, in turn, actuate the cable 68, and, since this cable isfixedly secured at 71 to section 16 and at to section 18, the said section 18 will be caused to travel upwardly or outwardl in a longitudinal direction on the section 1 at the same speed as the-said section 17 travels in a similar direction upon the section 16. 7

Thus it will be seen that rotary movement of the large drums 55 will project or extend the sections of the ladder each one sliding upon the one below it at auniform rate of speed, therefore providing for a symmetrical arrangement of the sections at any point during the extension movement of the ladder and hence securing practically uniform strength for the ladder as a whole at any total length thereof.

When the platform 12 is swung into any position in a vertical plane and when the ladder is extended to any desired degree, the ladder, as a whole, may be swung in any vertical plane about the pivot 19 by the following mechanism: A pair of chains or other cables 72 have one end of each secured to a shaft 73 mounted transversely near the lower end of the section 16 of the ladder in brackets 74. These chains thence pass around pulleys 75 secured to the side of the casing 7 and have their other ends passing one or more times around and secured to hubs 76 keyed against rotation but fitted to slide longitudinally on the shaft 45. The shaft 73 is provided at one end with a crank handle 77 for manually rotating it whole on its pivot.

and this rotation of the shaft 73 will wind V or unwind the chain 72 upon it therebymoving the ladder as a whole to various posi-' tions in a vertical plane.

A ratchet wheel 78 is fixedly securedi at one end of the shaft 73 for cotiperative engagement with a slot pawl 79 pivoted at 80 on section 16 of the ladder for prevent ing the unintentional unwinding of the chain 72 on the shaft 73. I

I have described above means appropriate for independently swinging the platform 12 on its pivot, for extending the sections of the ladder, and for swinging the ladder as tions may, however, be conducted at one time by the following apparatus: A'sleeve 81 is journaled in one'side of the casing 7 and provided with a crank handle 82 fixedly secured to the end thereof without the said casing. The other end of the sleeve 81 is secured by an anti-clock-wise operating ratchet clutch 81* to a pinion 83 which, in turn, meshes with a gear 84 secured against rotation on the shaft 59, which shaft also carries, as heretofore described, one of the pinions 57 which is meshed with one of the gears 56 on one of the large drums 55. The hubs .76 are provided with clutch jaws 8 5 fitted to engage recesses 86 in the large drums 55 for clutching the hubs 76 and drums 55 together; These hubs 76 may be slid into and out of clutching engagement with the drums 55 by means. of arms 87 pivoted at 88 to a plate 89 secured in the casing 7. One end of these arms 87 has a pin and slot engagement with collars 90 secured to the hubs 76, and the other ends of the said arms 87 have a screw threaded engagement, right and left hand respec- V tively, with a screw 91 mounted in the cas- These three opera- 80 mg 7, near one side thereof, and provided with a crank handle 92 for manual operation thereof. The rotation of the screw 91 will draw the ends of the arms 87 in engagement therewith toward each other or force them apart from each other, thereby clutching or unclutching respectively th hubs 76 with the large drums 55.

When the hubs 76 are clutched with the drums 55 the rotation of the crank handle 82 will cause the swinging of the platform 12 about its pivot, the swinging of the lad ders asa whole about their pivots, and the extension of a section of the ladders contemporaneously, because the rotation of the said crank handle 82 will, in turn, rotate the sleeve 81 which will rotate'the pinion 83; the latter, in turn, will rotate the gear 84, which will turn the shaft 59 and consequently the pinion 57 thereon. The pinion 57, being. meshed with the gear 56, will rotate. the corresponding large drum 155 which will, in turn, rotate the appropriate hub'7 6 keyed on the shaft 45. The rotation of this hub 76 will, in turn, rotate the shaft 45 which will rotate the other hub 76 and hence the other large drum 55, clutched to the said hub 76. The rotation of the shaft "15 will also, of course, rotate both drums 141 which are keyed thereto.

It will be understood, from the above, that the operation of the crank handle 82 will simultaneously actuate the cables 17, 62 and 72, thereby performing at the same time the three operations above mentioned, and hence moving the apparatus as a whole from its collapsed position into its completely extended operative position. It will be understood that the operation of the crank handle 82 may be stopped at any desired point, thereby leaving the ladder partially swung and partially extended.

When operated in this manner, the ap paratus may be locked in any desired state of its development by means of the pawl 93 pivoted at 94 in the casing 7, which pawl is arranged to engage the ratchet wheel 95 fixedly secured to the shaft 59.

Independent mechanism is provided for racing the ladder as a whole in various positions in a vertical plane about the pivot 19, which mechanism consists of a prop 96 pivoted to section 16 of the ladder at 97, which prop 96 has a slot 98 at the lower end thereof provided with a set of teeth 99 fitted to engage a pin 100 secured at one corner of the angular brace 101, 102, forming part of the platform 12.

A rod 103 has a pin and slot engagement at 104 with the part 102 and is secured at 105 to the prop 96.

The rod 103 is, in turn, secured to one arm 106 of a bell crank lever pivoted at 107 on one of the struts 1 1, the other arm 108 of the said bell crank being in turn secured to a rod 109, the other end of which rod is pivoted at 110 on a hand lever 111, pivoted at 112 on a disk 113 fixed to the platform 12.

l Vhen it is desired to brace the ladder as a whole in its upright position, the lever 111 is thrown down in a slot 11 1 to the position shown in Fig. 11, thereby, pulling down the arm 108 of the bell crank and swinging over the arm 106 thereof together with the rod 103, thus forcing the teeth 99 in the prop 96 into engagement with the pin 100, all as clearly shown in Fig. 13.

Then it is desired to swing the ladder as a whole about its pivot 19 in a vertical plane, the lever 111 may be raised until its pin 115 seats in the notch 116 in the slot 114, as shown in Fig. 13, in which case the arm 108 of the bell crank will be pushed upwardly, thereby causing the arm 106 to pull on the rod 103 and unseat the teeth 99 in the prop 96 from the pin 100, hence permitting the said prop to slide on the pin 100 while the ladder is being swung about the pivot 19.

Mechanism is also provided for locking the sections of the ladder in extended position or in withdrawn position, which mechanism includes a sprag 117 pivoted at 118 in the section 16 of the ladder, which sprag has a diagonally extending slot 119 arranged to receive a pin 120 secured on the end of a rod 121 arranged longitudinally of the said section 16 of the ladder. The other end of this rod is fastened to a sector 122 having a pin and slot engagement with the pivot 19 mounted in the bracket 124: on the section 16, which section has an arouate slot 125 in which is engaged one end of a rod 126, the other end of which rod is pivoted at 127 to a lever 128 fulcruined at 129 on the lever 111. This lever 128 has a fixed pin 130 thereon fitted to travel in the guide piece 131. After the sections of the ladder have been fully extended, the lever 128 may be swung down into the intermediate notch 132 in the guide 131, as shown in Fig. 13. This will draw the rod 126, the sector 122 and the rod 121 downwardly,

thereby causing the pin 120 to move downwardly in the slot 119 in the sprag 117 and causing the said sprag to swing inwardly toward the ladder sections about the pivot 18 and hence pass under the rungs 133 of the ladder sections, thereby locking them in their extended position.

lVhen it is desired to collapse the ladder, the lever 128 may be swung upwardly into the notch 13 1 in the guide 131, thereby,

through the appropriate connections, push- 1 ing upwardly the rod 121 and hence causing the pin 120 to traverse the slot 119 in an upward direction, swinging outwardly the sprag 117 and disengaging it from the rungs 133, hence permitting the sections of the ladder to be slid one upon another.

After the ladder has been entirely collapsed, the lever 128 maybe swung way down into the notch 135 in the guide 131, thus, through the appropriate connections, pulling the pin 120 down to the extreme lower end of the slot 119 and hence swinging the sprag inwardly to the limit of its movement, for causing it to project upwardly through the rungs of the ladder sections for holding them in collapsed arrangement.

In case it is desired at any time, while the ladder is extended, to rapidly collapse the same, the sprag 117 may be swung, as above described, to its inoperative position; after which the crank 82 may be turned in a clock-wise direction, thereby causing the tooth 136 on the sleeve 81 to disengage the pawl from the ratchet 95. This will permit the gears 83, 8 1, 57 and 56, and large drums 55, to rotate in the appropriate diections for permittin the sections of the ladder to descend freely under the force of gravity.

The speed of the descent maybe regulated by still further turning the crank 82 in a clock-wise direction and causing the tooth 136 to engage an angle lever 187 pivoted at 138 in the casing 7, thereby depressing said lever in the slot 139 in the band brake 140 which passes around a drum 141 secured against rotation on the shaft 59. The harder the lever 137 is forced against the band brake 140 the tighter will the drum 141 on the shaft 59 be gripped, thereby restricting the rotative speed of the gear 57 and hence also of the gear 56 and the large drums 55, thus limiting the rapidity of the descent of the upper sections of the ladder during the collapsing movement. A similar band brake 140* on the opposite side of the casing 7 is arranged to be constricted on the drum 141* on the shaft 58.

It will be noted that when the pawl 93 is swung out of engagement with a ratchet'95 by the tooth 136, it will be held out of engagement by the hook 144 pivoted at 145 in the casing 7. This hook 144 may be thrown out of engagement with the pawl 93 by turning the small lever 146 mounted in the easing, and, if desired, the pawl 93'may be held out of engagement with theratchet 95 by another small lever 147 also pivoted in the casing 7. I

From the above description, in which the construction and operation has been contemporaneously set forth, it will be evident that I have invented an apparatus of this character which is supported'upon the truck so as to rest in a vertical position, even though the ground may be unequal, which may be rotated freely upon the truck, which may be swung as a whole in a vertical plane about two separate pivots, and the extension ladder of which may be projected either horizontally or substantially vertically or at any angle between these extremes. These operations in developing and maneuvering the ladder may be conducted at the sametime or independently; and provision is made for rapidly collapsing the ladder and also for looking it in any stage of its extension or development.

As a part of this fire-fighting apparatus, I have invented a device for carrying human beings, or indeed any objects, from the upper or outer portion of the ladder down to the base thereof without the necessity of firemen or other operators manually transporting the same. This apparatus consists of an endless chain or cable 148. which passes around a pulley 149 secured at the upper end of the section 18 of the ladder, around pulleys 150 and 151 mounted in a base 152 on the top 9 of the casing 7, and also around a pulley 153 attached to the end of a chain 154, which cured at 156 to a staple 157 on the section 16 of the ladder.

Part of the endless chain or cable 148 passes through abrake constituted by an abutment 158 firmly secured on the top 9, and a shoe 159secured to said abutment 158 by a free link 160 and another link 161 pivoted on the shoe 159 but fixed to move in the abutment 158 with the lever 162. 7

It will be seen that when the lever 162 is thrown upwardly the shoe 159 will be moved away from the abutment 158 thus permitting the chain or cable 148 to pass freely therebetween, while the downward movement of the lever 162 will have the eflect of gripping the chain 148. By this arrangement anyperson or thing may be secured to one side of the endless chain 148 near the upper end" thereof and be permitted to descend to the top 9 of the casing 7 by the force of gravity,

the safety of said descent being regulated through the lever 162 in charge of an operative on the top 9. Guard chains 163, 164,

are secured at two placesto the prop 96 and at approximately the same place to an upright 165 on the outer edge of the top 9 of the casing 7, as an aid to operatives standing 7 whereby the said casing remains level no r matter what the angle of the truck, and means for securing the casing in various adjustments in a vertical plane.

2. Apparatus of the character described comprising a suitable truck, a casing mounted thereon, a ladder carried by the casing, the said casing being'mounted to oscillate on the truck in any vertical plane under the influence of gravity, whereby the said casing remains level no matter what the angle of the truck, and means for securing the easing in various adjustments in any vertical plane.

3. Apparatus of the character described comprising a suitable truck, a rotatable casing mounted thereon, a ladder carried by comprising a suitable truck, a hollow casing pivotally supported thereon at its upper central portion whereby it is free to oscillate under the influence of gravity, a ladder carried by said casing, and means for securing the casing in various oscillatory adjustments.

5. Apparatus of the character described comprising a suitable truck, a rotatable hollow casing pivotally supported thereon at its upper central. portion whereby it is free to oscillate under the influence of gravity, a ladder carried by said casing, and means for securing the casing in various oscillatory adjustments.

6. Apparatus of the character described, comprising a suitable truck, a rotatable hol low casing pivotally supported at its upper central portion whereby it is free to oscillate under the influence of gravity toward any point of the compass, a ladder carried by said casing, and means for securing'the casing in any oscillatory adjustment.

7. Apparatus of the character described comprising a suitable truck, a casing mounted thereon, a platform mounted to swing in a vertical plane on the casing, a sectional ladder carried by the platform, and adapted to swing in a vertical plane and means under the control of a single operating device for extending the ladder, for swinging the ladder in a vertical plane on the platform, and for swinging the platform in a vertical plane on the casing.

8. Apparatus of the character described comprising a suitable truck, a casing mounted thereon, a platform on the casing, a ladder carried by the platform, and means for simultaneously extending the ladder, swinging the same in a vertical plane on the platform, and swinging the platform in a vertical plane on the casing.

9. Apparatus of the character described comprising a suitable truck, a casing mounted thereon, a platform on the casing, and a ladder carried by the platform, the said platform being pivoted intermediate its ends at the edge of the casing and the ladder being pivoted intermediate its ends at the edge of the platform, whereby the platform and ladder are fitted to swing in a vertical plane simultaneously about two pivots.

10. Apparatus of the character described comprising a suitable truck, a casing mounted thereon, a platform on the casing, and a ladder carried by the platform, the said platform being pivoted at its center at the edge of the casing and the ladder being pivoted at its center at the edge of the platform, whereby the platform and ladder are fitted to swing in a vertical plane simultaneously about two pivots.

11. Apparatus of the character described comprising a suitable truck, a sectional ladder mounted thereon, means for raising and extending the ladder, means for holding the ladder in its raised and extended position, means for throwing the last mentioned means out of operation, whereby the ladder may be permitted to return to its lowered collapsed position under the force of gravity, and means for regulating the rate of said lowering and collapsing movements.

12'. Apparatus of the character described comprising a suitable truck, a sectional ladder thereon, means for extending the ladder, an endless chain passing about a pulley on the upper section of the ladder, about two pulleys on the truck, and about a fourth pulley secured by a flexible connection to the lower section of the ladder, the said endless chain passing through a brake on the truck, whereby the endless chain may be projected with the extension of the ladder, and whereby a body may be secured to one part of the endless chain when the ladder is in its extended position and transported to the truck at reduced speed.

13. Apparatus of the character described comprising a suitable truck, a rotatable casing mounted thereon to oscillate in a vertical plane, a ladder carried by the casing,

and means for securing the casing in various rotary adjustments and in various adjustments in a vertical plane.

14:. Apparatus of the character described comprising a suitable truck, a casing mounted thereon, a platform pivoted on the casing, a sectional ladder pivoted on the platform, and means under the control of a single operating device for causing the simultaneous collapsing of the ladder, its swinging down to its resting position on the platform, and the swinging of the platform back to its resting position on the casing.

In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two witnesses, this fourth day of December 1912.

GIOVANNI PREDONZAN.

Witnesses Capt. UMBROSING, VINCENT BURES.

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

Washington, D. C.

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