US1728854A

US1728854A - Ladder

Info

Publication number: US1728854A
Application number: US231894A
Authority: US
Inventors: Melvin K Carr
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-11-08
Filing date: 1927-11-08
Publication date: 1929-09-17
Anticipated expiration: 1946-09-17

Description

Sept. 17, 1929. M. K. CARR 1,728,854

LADDER Filed Nov. 8, 1927 s Sheets-Sheet 1 INVENTOR Melvin JiLOa/w ATTOR NEY Sept. 17, 1929. M. K. CARR 1,728,854

LADDER Filed Nov. 8, 1927 3 Sheets-Sheet 2 I INVENTOR Melt 170' 181301 1 ATTORNEY M. K. CARR Sept. 17, 1929.

LADDER 3 Sheets-Sheet 3 Filed NOV. 8, 1927 INVENTOR Melt in 7i. Car/ ATTORNEY Patented Sept. 17, 1929 UNITED- STATES it MELVIN KJOARR, or BREMERTON, WASHINGTON LADDEB Application filed November larly disposed axesto permit the ladder to.

reach points at either side of the truck or rear- Wardly of the same. t, Still another object of the invention resides in the provision of'an extensible ladder normally occupying a horizontal position on a vehicle or truck to which it is attached but is arranged to be automatically set and sustained at any desired angle about two right angular-1y disposed axes. WVith the preceding and other objects and advantages in mind, the inventionconsists in the novel combination of elements, constructions and arrangement of parts to .be

hereinafter specifically referred to, claimed and illustrated in the accompanying drawings, wherein: I

Figure 1 is a side elevation of a fire truck .30 equipped with my invention and illustrating the latter in vertical position; a

Figure 2 is a similar view and illustrating the ladder in horizontal or normal position;

Figure 3 is an enlarged horizontal sectional view on line 33of Figure 1;

Figure 4 is a topplan view; Figure 5 is a transverse sectional view takenon line 55 of Figure 4;

Figure 6 is an enlarged fragmentary longitudinal sectionalcview taken on line 6-6 of Figure 4; with the ladder in raised position; Figure 7 is anlenlargedview of the ladder partly in elevation'and partly in vertical section, the ladder being illustrated in col- 4 lapsed position;and

8, 1927.; Serial No. 231,894. 4

;Figure,8 is a view similar to Figure 7 illus trating theladdcrsections in extended posi-e tion. I Tm Referring to the invention in detail a conventional truck ormotor vehicle5, such as is now generally usedin fire/fighting equipment, and whose chassis frame includes parallel side channel bars 6 and an intermediate channel bar 7, isfprovided.

Forthe purpose ofmounting my improved ladderon the trucka pair of vertically disposed arms Sis attached toxone of the channel bars 6 and the channel 7 atone side of the I truck adjacent its forward end. A U shaped member 9 is disposedbetween.thesearms and has its extremities :pivotally connected IWlth the upper ends of the arms by horizontal pivot elementslO; I .An inverted T fittingll is provided to afford a mounting for the ladder whereby it maybe swung to positions at either side of the truck or vehicle. For this purpose the T fitting is disposed between thedegsnof the U-shaped member, with its laterally. projecting ends extending-parallel to the inter-. 7 0 mediate leg of the U-Shaped member, and constitutes trunnions 12 which are j ournalled in bearingsl3 mounted upon the upper face of:

the intermediate leg of the U-shaped member.

The ladder consists of a plurality of telescopic slidable tubes 14, the outer one of which has its lower. end threadedly. received in the vertical-branch of the vT fitting while the-in-' nerlnost one has itsl'owerend closed; Normally nested telescopically engaged'extensibleladder sections 15 are'fixed to thetelescopic tubes, eachcomprising pairs of parallel bars 16, dispo sedupon opposite sides of its. respective tube and connected at their upper en'ds'to rectangular heads 17,. the latter hav-- ing central longitudinally alined openings 18 receiving the outerends of the tubes. The parallel bars of the lowermost ladder section, however, are attached to a head-17 received on the lower end of the outermost tube.

These heads are secured to their respective tubes by suitable fastenings 19. Spaced rungs 19 are carried by each pair of parallel bars 16.-

As illustrated particularly in Figures 7 and 8 parallel bars of each ladder section are slidable along the parallel bars of the ladder section next in order, and to facilitate movement of these bars the opposite ends of each of the latter carry rollers which engage the adjacent bars. It will be observed that the rollers at the inner ends of the bars engage the outer faces of the adjacent bars while the rollers at the outer ends of the bars ongage the inner faces of the adjacent bars.

To facilitate movement of the upper end of the outermost ladder section against the walls of a building, laterally projecting rollers 21 are carried by brackets 22 attached directly to this ladder section.

The invention contemplates extending the ladder sections by means of compressed air or fluid, and to eliminate shocks and jars incident to the sections reaching the end of their movement, shock absorbing springs 23 are secured to the under face of each of the heads to beengaged by stops or abutments 24 carried by each ladder section at opposite sides thereof. These stops or abutments consist U oflengths of metal bent into U-shaped formation and project laterally towards each other from the lower ends of the parallel bars composing the ladder sections.

For the purpose of rocking the ladder to an 7 upright position and retaining it in this position for use, a semi-circular counter balancing weight 25 is secured to the under face of the intermediate leg of the U-shaped memher 9.- A pivoted latch element 26 attached to one of the chassis frame members adjacent its forward end engages the counter balancing weight to latch it in an elevated position where the ladder will rest in a horizontal po sition upon the chassis frame ofthe truck or motor vehicle. A hand lever 27 is pivoted to the chassis frame adjacent the drivers seat and is operatively connected to the latch element by means of a connecting rod 28 whereby the former may be moved to operative and inoperative positions, as desired.

Cooperating with the counter balancing weight in raising the ladder is a drive shaft 29 from the motor vehicle prime mover, not shown, equipped with a worm gear 30 meshing with teeth 31 on one face of the counter balancing weight to rock the latter forwardly or rearwardly incident to the operation of the prime mover. It follows that upon dis engagement of the latch element from the counter balancing weight and rotation of the drive shaft in onedirection,the ladder will be. raised to operative position and reversely counter rotation of theshaft will rock the ladder to a horizontal position to lie upon the chassis frame. 7

To adjust or swing the ladder to either side of the motor vehicle, a worm shaft 32 journalled in bearings 33 within the U-shaped member 9 extends transversely of thechassis frame and engages a worm wheel 34 carried by one of the pintles 12 of the T fitting 11. One end of this worm shaft projects beyond one side of the chassis frame and carries a hand wheel 85 whereby the fitting is oscillated in its bearings to dispose the ladder at the desired side of the motor vehicle.

A compressed air reservoir 37 attached to the chassis frame by straps or other suitable fastenings 38 communicates with the T fitting by way of a flexible conduit 39 and conducts compressed air from the reservoir to the telescopic tubes to lift or raise the ladder sections. A control valve 40 is interposed in the conduit 39 to control the passage of compressed air to the T fitting and communicating telescopic tubes. It will be observed that the ladder sections will be raised or lowered with the desired rapidity according to the position of the control valve.

A suitable air compressor 41 mounted on the chassis frame adjacent its forward end communicates with the air reservoir by way of a supply pipe 42. Suitable drive means is provided for taking power from the shaft 29 to the shaft of the air compressor which may consist of pulleys 43 fixed to these shafts and engaged by an endless belt 44;.

A pressure release valve 45 communicates with the T fitting and is adapted to be manually operated to permit air pressure within the telescopic tubes to exhaust to the atmosphere and allow the ladder sections to gravitate to normal position.

As illustrated in Figure l a hose 42 may be attached in any suitable manner to the ladder sections and the apparatus utilized as a water tower.

To prevent the counter balancing weight from oscillating when the latter is released, contractile springs so are connected to the weight and to brackets 47 attached to the under face of the chassis frame adjacent its forward end.

lVhat is claimed is:

1. In combination a vehicle, a ladder pivotally attached thereto and normally resting thereon and extending horizontally and 1ongitudinally thereof, a weighted toothed element attached to the pivoted end of the ladder and arranged to normally urge the latter in an upright position, means for normally rendering the counter balancing element inactive, and a driven element engaging the teeth of the counter balancing element whereby the latter will move forwardly or rearwardly to elevate or lower thela-dder.

2. In an extensible ladder a base, a universal mounting on the base, a plurality of normally telescoped ladder sections one of which being fixed to the universal mounting, means for extending and collapsing the ladder sections, shock absorbing springs carried by one end of each ladder section, and abutments carried by the opposite end of the sections to engage the springs when the latter are extended.

3. In combination a base, a pair of upstanding arms attached thereto, a U-shaped member pivotally supported between the arms to swing about a horizontal axis, an extensible ladder attached to the U-shaped member and normally disposed in a horizontal position, a toothed member fixed to the U-shaped memher, and motor driven means operatively engaging the toothed member whereby to raise and lower the ladder.

4. In a ladder, a base, a ladder mounting pivoted on the base to move about a horizontal axis, a ladder normally disposed in a horizontal position on the base and having one end pivotally attached to the mounting for movement in a plane at right angles to the plane of movement of the mounting, means for rocking the mounting to elevate or lower the ladder, and means for rocking the ladder on its pivot whereby to reach points offset from the base.

5. In combination a base, a member pivoted thereto to swing about a horizontal axis, a ladder attached to the member, a counter balancing weight attached to the member, latch means for normally holding the counter balancing member beyond dead center to retain the ladder in a horizontal position but operable to release the counter balancing weight to elevate the ladder.

6. In a ladder, a base, a bracket journaled thereon to swing about a horizontal axis, a pipe fitting journaled in the bracket to swing at right angles to the plane of movement of the bracket, a gear fixed to one end of the pipe fitting, a driven element supported in the bracket and engaging the gear, and a plurality of telescopic tubes one of which being fixed to the fitting and having communication therewith, and means for supplying compressed fluid to the fitting to extend the telescopic tubes.

7. In a ladder, a base, a bracket journaled thereon to swing about a horizontal axis, a pipe fitting ournaled in the bracket to swing at right angles to the plane of movement of the bracket, and a plurality of telescopic tubes one of which being fixed to the fitting and having communication therewith, and means for supplying compressed fluid to the fitting to extend the telescopic tubes, means for" adjusting the bracket about its pivot to elevate the telescopic tubes, and means for adjusting the fitting to dispose the tubes in various predetermined angular positions.

8. In a ladder, a base, a bracket journalled thereon to swing about a horizontal axis, a mounting journall-ed in the bracket to swing at right angles to the plane of movement of the bracket, a ladder carried by the mounting, a gear fixed to the mounting, a driveelement supported by the bracket and engaging