US2853221A - Ladder lock - Google Patents

Ladder lock Download PDF

Info

Publication number
US2853221A
US2853221A US479134A US47913454A US2853221A US 2853221 A US2853221 A US 2853221A US 479134 A US479134 A US 479134A US 47913454 A US47913454 A US 47913454A US 2853221 A US2853221 A US 2853221A
Authority
US
United States
Prior art keywords
ladder
section
plunger
extension
fly
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US479134A
Inventor
Herman J Troche
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
J H HOLAN CORP
Original Assignee
J H HOLAN CORP
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by J H HOLAN CORP filed Critical J H HOLAN CORP
Priority to US479134A priority Critical patent/US2853221A/en
Application granted granted Critical
Publication of US2853221A publication Critical patent/US2853221A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • E—FIXED CONSTRUCTIONS
    • E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
    • E06C—LADDERS
    • E06C7/00—Component parts, supporting parts, or accessories
    • E06C7/08—Special construction of longitudinal members, or rungs or other treads
    • E—FIXED CONSTRUCTIONS
    • E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
    • E06C—LADDERS
    • E06C1/00—Ladders in general
    • E06C1/02—Ladders in general with rigid longitudinal member or members
    • E06C1/04—Ladders for resting against objects, e.g. walls poles, trees
    • E06C1/08—Ladders for resting against objects, e.g. walls poles, trees multi-part
    • E06C1/12—Ladders for resting against objects, e.g. walls poles, trees multi-part extensible, e.g. telescopic

Definitions

  • This invention relates to a utility vehicle having an extensible ladder and more particularly relates to an improved latch assembly for preventing uncontrolled extension of the ladder.
  • the extensible ladder to which this invention is applied usually embodies a base and a fly ladder section mounted on the bed of a utility vehicle for swingable and tiltable movement to provide access to overhead traflic lights, street lamps and similar objects. It is desirable that each of the ladder movements be controlled. For example, uncontrolled extension of the ladder sections is undesirable, particularly when the ladder assembly is located in a horizontal storage position on top the vehicle cab when sudden stopping of the vehicle might result in an extension of the ladder sections.
  • a principal object of this invention relates to the provision of a releasable latch assembly for preventing uncontrolled extension of an extensible ladder.
  • Another object of this invention relates to the provision of a latch assembly which automatically conditions the ladder for controlled extension.
  • an extensible ladder having a base section operatively supported on a utility vehicle and carrying an extensible fly section which may be positively extended by a winch mechanism
  • an improved latch assembly which includes a plunger carried by the fly section and normally biased for latching engagement with a stop member on the base section to prevent extension of the fiy section.
  • the latch assembly also includes an arrangement for automatically disengaging the plunger from the stop member when the winch is operated to extend the ladder and for automatically conditioning the plunger for latching engagement with the stop member when the winch is released for retraction of the extended ladder.
  • Fig. 1 is a side view of the utility vehicle illustrating the extensible ladder in its storage position on the vehicle;
  • Fig. 2 illustrates the ladder assembly and its elevating mechanism in relation to its support on the vehicle
  • Fig. 3 is a plan view of portions of the ladder assembly illustrating the ladder extension mechanism
  • Figs. 4 and 5 illustrate that portion of the ladder assembly which carries the latch assembly with the latch engaged and disengaged respectively;
  • Fig. 6 is a view taken along the lines 6--6 in Fig. 4;
  • Fig. 7 illustrates the plunger portion of the latch assembly in relation to the supporting portion of the fly ladder section
  • Fig. 8 is a view taken along the lines 8-8 in Fig. 7;
  • Fig. 9 is an exploded view of the latch plunger and its releasing lever.
  • a utility vehicle 10 having a cab 11 and a ladder supporting bed 12 on which is mounted a vertical stanchion or mast 13 for supporting the extensible ladder assembly.
  • This assembly is made up of the base section 15 and the fly section 16 and, as best shown in Fig. 2 of the drawings, the lower end of the base section 15 is pivotally coupled at 14 to the top of the mast 13 so that the entire ladder assembly may be tilted in a vertical plane relative to the bed and cab of the vehicle.
  • the mast 13 is customarily supported for rotation about a vertical axis on the vehicle bed 12 so that the ladder assembly may be swung to any position in a horizontal plane; the tilting and swinging movement permitting location and direction of the ladder assembly towards overhead traflic lights, street lamps and similar objects.
  • fly section 16 of the ladder is slideably supported on the base section 15 within suitable guide channels 17 for extension by a suitable winch 18 carried by the base ladder section 15.
  • the extension is accomplished through a winch cable 20 which extends around a free spinning pulley 21 at the upper end of the base section 15 and thence is connected to the fly section 16.
  • the winch 18 may be operated to gain access to the lamp.
  • the ladder section 16 may be extended without operating the winch and that themomentum of swinging and tilting movement might also result in an uncontrolled extension.
  • the ladder assembly is located in the storage position across the cab 11, as shown in Fig.
  • this invention contemplates the provision of a latch mechanism, the preferred form of which is illustrated in Figs. 4 through 9 of the drawings, which not only prevents uncontrolled extension of the ladder sections but which also is automatically conditioned to release the sections when the winch is operated for extension of the sections.
  • the latch assembly includes a stop member in the form of a bracket 25 mounted on the top edge of one side rail of the base section 15 and a plunger 27 which is carried within a hollow rung 28 of the fly section 16.
  • the plunger 27 is biased axially by means of a coiled spring 2% into releasable engagement with the stop mem ber 25 as best shown in Figs. 4 and 5 of the drawings.
  • the inner end of the plunger 27 is shown as having a guide slot 30 for receiving the anvil portion 31 of a latch control lever 33.
  • the lever 33 is pivotally supported by a bracket 34 on the hollow ladder rung 28 for controlled intersection with the guide slot 30.
  • the winch cable 20 is threaded through an aperture 36 in the lever 33 so that when a positive extension force is transmitted from the winch 18 as shown by the arrow in Fig. 5 it will turn the lever 33 about its pivot in a direction to position the anvil portion 31 inthe guide slot 30 Where it engages and moves the plunger 27 axially into the ladder rung 28 and out of engagement with the stop member 25, thereby automatically permitting controlled extension of the fly section 16 by the winch.
  • release of the winch for retraction of the fly section frees the lever 33 and permits the coiled plunger spring 29 to position the plunger 27 for engagement with the stop member 25, as shown in the dotted lines in Fig. 4.
  • the inner end of the spring 29 engages a rivet 35 fixed in the hollow rung 28.
  • operation of the winch automatically operates to release the latch and extend the fly section 16 and also automatically conditions the latch for operation during retraction of the fly section.
  • the latch arrangement is such that it automatically re- 3 engages upon 'i'etraction ofthe extended ladder section so that the operator is not required to perform any additional operations and yet, the operator is secure in the knowledge that the ladder sections will not inadvertantly extend during the location and direction of the ladder or while the vehicle is transporting the ladder.
  • each of said ladder sections having ap'air of parallel spaced 'side rails interconnected by a plurality of parallel rungs spaced along the side rails, the dimension between the side rails of the base section being greater than the same dimension of the fly section to permit nesting of the fly section between the siderails of the base section in the retracted position, a bracket secured to the top edge of one of the side rails of the base section, one of the rungs on the fly section being hollow,'a plungerfreely disposed within said hollow rung, resilient means coacting between the hollow rung and the plungerto bias the plunger in an outwardly projecting position beyond the fly section side rail and into the plane of the adjacent base section side rail for interlocking engagement with said bracket to prevent extension of the fly section, and means for retracting the plunger out of engagement with the bracket for controlled extension of the flysection, said last-mentioned means including aligned slots in the plunger and hollow rung
  • each of said ladder sections having a pair of parallel spaced side rails interconnected by a plurality of parallel rungs spaced along the side rails, the dimension between the side rails of the base section being greater than the same dimension of the fly section to permit nesting of the fly section between the side rails of the base section in the retracted position, a bracket secured to the top edge of one of the 'side rails of the base section, one of the rungs on the fly section being hollow, a plunger freely disposed within said hollow rung,'resilient means coacting between the hollow rung and the plunger to bias the plunger in an outwardly projecting position beyond the fly section'side rail and into the plane of the adjacent base section side rail for interlocking engagement with said bracket to prevent extension of the fly section, and means for retracting the plunger out of engagement with the bracket for controlled extension of the fly section, being a portion of'said bracket being parallel to the plane of its supporting 's'

Description

Sept. 23, 1958 H. J. TROCHE 2,353,221
LADDER LOCK Filed Dec. 31, 1954 2 Sheets-Sheet 1 NVENTOR. M fi awm/v J rec c/hc ATT ormey Sept. 23, 1958 H. J. TROCHE 2,353,221
LADDER LOCK Filed Dec. 51, 1954 2 SheetsSheet 2 IN V EN TOR.
United States Patent LADDER LOCK Herman I. Troche, Fairview Park, Ohio, assignor to J. H. lblfilan Corporation, Cleveland, Ohio, a corporation of Application December 31, 1954, Serial No. 479,134
2 Claims. (Cl. 228-65) This invention relates to a utility vehicle having an extensible ladder and more particularly relates to an improved latch assembly for preventing uncontrolled extension of the ladder.
The extensible ladder to which this invention is applied usually embodies a base and a fly ladder section mounted on the bed of a utility vehicle for swingable and tiltable movement to provide access to overhead traflic lights, street lamps and similar objects. It is desirable that each of the ladder movements be controlled. For example, uncontrolled extension of the ladder sections is undesirable, particularly when the ladder assembly is located in a horizontal storage position on top the vehicle cab when sudden stopping of the vehicle might result in an extension of the ladder sections.
Accordingly, a principal object of this invention relates to the provision of a releasable latch assembly for preventing uncontrolled extension of an extensible ladder.
Another object of this invention relates to the provision of a latch assembly which automatically conditions the ladder for controlled extension.
Briefly, in accordance with this invention, an extensible ladder having a base section operatively supported on a utility vehicle and carrying an extensible fly section which may be positively extended by a winch mechanism is provided with an improved latch assembly which includes a plunger carried by the fly section and normally biased for latching engagement with a stop member on the base section to prevent extension of the fiy section. The latch assembly also includes an arrangement for automatically disengaging the plunger from the stop member when the winch is operated to extend the ladder and for automatically conditioning the plunger for latching engagement with the stop member when the winch is released for retraction of the extended ladder.
In the drawings;
Fig. 1 is a side view of the utility vehicle illustrating the extensible ladder in its storage position on the vehicle;
Fig. 2 illustrates the ladder assembly and its elevating mechanism in relation to its support on the vehicle;
Fig. 3 is a plan view of portions of the ladder assembly illustrating the ladder extension mechanism;
Figs. 4 and 5 illustrate that portion of the ladder assembly which carries the latch assembly with the latch engaged and disengaged respectively;
Fig. 6 is a view taken along the lines 6--6 in Fig. 4;
Fig. 7 illustrates the plunger portion of the latch assembly in relation to the supporting portion of the fly ladder section;
Fig. 8 is a view taken along the lines 8-8 in Fig. 7; and
Fig. 9 is an exploded view of the latch plunger and its releasing lever.
Referring now more particularly to Figs. 1, 2 and 3 of the drawings, there is shown a utility vehicle 10 having a cab 11 and a ladder supporting bed 12 on which is mounted a vertical stanchion or mast 13 for supporting the extensible ladder assembly. This assembly is made up of the base section 15 and the fly section 16 and, as best shown in Fig. 2 of the drawings, the lower end of the base section 15 is pivotally coupled at 14 to the top of the mast 13 so that the entire ladder assembly may be tilted in a vertical plane relative to the bed and cab of the vehicle. The mast 13 is customarily supported for rotation about a vertical axis on the vehicle bed 12 so that the ladder assembly may be swung to any position in a horizontal plane; the tilting and swinging movement permitting location and direction of the ladder assembly towards overhead traflic lights, street lamps and similar objects.
As best shown in Figs. 2 and 3 of the drawings, the
fly section 16 of the ladder is slideably supported on the base section 15 within suitable guide channels 17 for extension by a suitable winch 18 carried by the base ladder section 15. The extension is accomplished through a winch cable 20 which extends around a free spinning pulley 21 at the upper end of the base section 15 and thence is connected to the fly section 16. Thus, once the ladder assembly is properly located and directed towards an overhead lamp or the like, the winch 18 may be operated to gain access to the lamp. I It will readily be apparent that the ladder section 16 may be extended without operating the winch and that themomentum of swinging and tilting movement might also result in an uncontrolled extension. Similarly, when the ladder assembly is located in the storage position across the cab 11, as shown in Fig. l of the drawings, a sudden stop of the vehicle might also result in an uncontrolled extension of the fly section 16. Accordingly, this invention contemplates the provision of a latch mechanism, the preferred form of which is illustrated in Figs. 4 through 9 of the drawings, which not only prevents uncontrolled extension of the ladder sections but which also is automatically conditioned to release the sections when the winch is operated for extension of the sections.
The latch assembly includes a stop member in the form of a bracket 25 mounted on the top edge of one side rail of the base section 15 and a plunger 27 which is carried within a hollow rung 28 of the fly section 16. The plunger 27 is biased axially by means of a coiled spring 2% into releasable engagement with the stop mem ber 25 as best shown in Figs. 4 and 5 of the drawings. In Figs. 7, 8 and 9 of the drawings, the inner end of the plunger 27 is shown as having a guide slot 30 for receiving the anvil portion 31 of a latch control lever 33. The lever 33 is pivotally supported by a bracket 34 on the hollow ladder rung 28 for controlled intersection with the guide slot 30. The winch cable 20 is threaded through an aperture 36 in the lever 33 so that when a positive extension force is transmitted from the winch 18 as shown by the arrow in Fig. 5 it will turn the lever 33 about its pivot in a direction to position the anvil portion 31 inthe guide slot 30 Where it engages and moves the plunger 27 axially into the ladder rung 28 and out of engagement with the stop member 25, thereby automatically permitting controlled extension of the fly section 16 by the winch. Similarly, release of the winch for retraction of the fly section frees the lever 33 and permits the coiled plunger spring 29 to position the plunger 27 for engagement with the stop member 25, as shown in the dotted lines in Fig. 4. The inner end of the spring 29 engages a rivet 35 fixed in the hollow rung 28.
Thus, operation of the winch automatically operates to release the latch and extend the fly section 16 and also automatically conditions the latch for operation during retraction of the fly section.
The latch arrangement is such that it automatically re- 3 engages upon 'i'etraction ofthe extended ladder section so that the operator is not required to perform any additional operations and yet, the operator is secure in the knowledge that the ladder sections will not inadvertantly extend during the location and direction of the ladder or while the vehicle is transporting the ladder.
I have shown and described what I consider to be the preferred embodiments of my invention along with similar modified forms and suggestions, and it will be obvious to those 'skilled'in the art that other changes and modifications may be made without departing from the scope of this invention as defined by the appended claims.
1. In combination with 'a ladder having a base section and an extensible fly section, each of said ladder sections having ap'air of parallel spaced 'side rails interconnected by a plurality of parallel rungs spaced along the side rails, the dimension between the side rails of the base section being greater than the same dimension of the fly section to permit nesting of the fly section between the siderails of the base section in the retracted position, a bracket secured to the top edge of one of the side rails of the base section, one of the rungs on the fly section being hollow,'a plungerfreely disposed within said hollow rung, resilient means coacting between the hollow rung and the plungerto bias the plunger in an outwardly projecting position beyond the fly section side rail and into the plane of the adjacent base section side rail for interlocking engagement with said bracket to prevent extension of the fly section, and means for retracting the plunger out of engagement with the bracket for controlled extension of the flysection, said last-mentioned means including aligned slots in the plunger and hollow rung and a bell crank 'lever pivotally mounted on the hollow rung with one extremity adapted to be positioned into the aligned 'slots to engage and retract the plunger against the bias into the hollow rung, and a winch having a flexible connection to the other extremity of the bellcrank lever and coacting therewith to position the lever for retraction of the plunger and extension of the ladder fly section.
2. In combination with a ladder having a base section and an extensible fly section, each of said ladder sections having a pair of parallel spaced side rails interconnected by a plurality of parallel rungs spaced along the side rails, the dimension between the side rails of the base section being greater than the same dimension of the fly section to permit nesting of the fly section between the side rails of the base section in the retracted position, a bracket secured to the top edge of one of the 'side rails of the base section, one of the rungs on the fly section being hollow, a plunger freely disposed within said hollow rung,'resilient means coacting between the hollow rung and the plunger to bias the plunger in an outwardly projecting position beyond the fly section'side rail and into the plane of the adjacent base section side rail for interlocking engagement with said bracket to prevent extension of the fly section, and means for retracting the plunger out of engagement with the bracket for controlled extension of the fly section, being a portion of'said bracket being parallel to the plane of its supporting 's'ide rail and transverse to the axis of said plunger, and the remaining portion of said bracket in the direction of extension intersects the plane of its supporting side rail at an angle suflicient to guide the extended plunger along both portions of the bracket for engagement with the rea'rmost edge upon retraction of the ladder fly section.
References Cited in the file of this patent UNITED STATES PATENTS 356,088 Barnes Jan. 18, 1 887 441,159 Herbert Nov. 25, 1890 709,402 Herndon Sept. 16, 1902 857,785 Bobbit June 25, 1907 930,598 Henry Aug. 10, 1909 1,228,248 Rudd May 29, 1917 2,559,992 Painter July 10, 1951 FOREIGN PATENTS 17,594 Great Britain 1'905
US479134A 1954-12-31 1954-12-31 Ladder lock Expired - Lifetime US2853221A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US479134A US2853221A (en) 1954-12-31 1954-12-31 Ladder lock

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US479134A US2853221A (en) 1954-12-31 1954-12-31 Ladder lock

Publications (1)

Publication Number Publication Date
US2853221A true US2853221A (en) 1958-09-23

Family

ID=23902787

Family Applications (1)

Application Number Title Priority Date Filing Date
US479134A Expired - Lifetime US2853221A (en) 1954-12-31 1954-12-31 Ladder lock

Country Status (1)

Country Link
US (1) US2853221A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3083789A (en) * 1959-11-11 1963-04-02 Kloeckner Humboldt Deutz Ag Ladder device
US4640387A (en) * 1984-12-12 1987-02-03 Firma Albert Bocker Gmbh & Co. Kg. Elevator comprising telescopic sections, and a locking device therefor
FR2614067A1 (en) * 1987-04-14 1988-10-21 Quere Marcel Self-elevating ladder
US20160108673A1 (en) * 2009-09-29 2016-04-21 Wildcat Capital Llc Ladder safety device, systems and methods of arresting falls from ladders

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US356088A (en) * 1887-01-18 Fire-ladder apparatus
US441159A (en) * 1890-11-25 Henry b
US709402A (en) * 1902-04-26 1902-09-16 Edward A Herndon Extension-ladder and truck therefor.
GB190517594A (en) * 1905-08-31 1906-04-05 Antonin Kroupa Improvements in Ladders.
US857785A (en) * 1906-08-30 1907-06-25 Frank A Bobbitt Extension-ladder.
US930598A (en) * 1909-02-13 1909-08-10 Robert Henry Sash-fastener.
US1228248A (en) * 1916-06-20 1917-05-29 Harry H Rudd Hinge-joint for folding ladders.
US2559992A (en) * 1946-04-26 1951-07-10 Jr John L Painter Extension ladder

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US356088A (en) * 1887-01-18 Fire-ladder apparatus
US441159A (en) * 1890-11-25 Henry b
US709402A (en) * 1902-04-26 1902-09-16 Edward A Herndon Extension-ladder and truck therefor.
GB190517594A (en) * 1905-08-31 1906-04-05 Antonin Kroupa Improvements in Ladders.
US857785A (en) * 1906-08-30 1907-06-25 Frank A Bobbitt Extension-ladder.
US930598A (en) * 1909-02-13 1909-08-10 Robert Henry Sash-fastener.
US1228248A (en) * 1916-06-20 1917-05-29 Harry H Rudd Hinge-joint for folding ladders.
US2559992A (en) * 1946-04-26 1951-07-10 Jr John L Painter Extension ladder

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3083789A (en) * 1959-11-11 1963-04-02 Kloeckner Humboldt Deutz Ag Ladder device
US4640387A (en) * 1984-12-12 1987-02-03 Firma Albert Bocker Gmbh & Co. Kg. Elevator comprising telescopic sections, and a locking device therefor
FR2614067A1 (en) * 1987-04-14 1988-10-21 Quere Marcel Self-elevating ladder
US20160108673A1 (en) * 2009-09-29 2016-04-21 Wildcat Capital Llc Ladder safety device, systems and methods of arresting falls from ladders

Similar Documents

Publication Publication Date Title
US4826387A (en) Vehicle roof rack
US3845596A (en) Drive system for a telescopic boom
US2795303A (en) Masts or towers
US5445487A (en) Boom lift apparatus mountable to different support structures
US3756622A (en) Retractable vehicle step
CA1080668A (en) Extensible boom
US20100264618A1 (en) Automated retractable step apparatus
OA07744A (en) Elevator comprising at least one telescopic mast.
US3038185A (en) Automatic leveler for aircraft loading and unloading structure
US2853221A (en) Ladder lock
US2647677A (en) Airplane step
US4356498A (en) Tower assembly
US2928493A (en) Telescoping boom
US3405814A (en) Weather tent for cargo hatches
US2701068A (en) Cargo loading hoist
US3980121A (en) Bracket for use in a retractable awning
US3086152A (en) Automatic motor-driven leveler for loading ramp
US2514052A (en) Industrial truck
US4206833A (en) Mobile aerial tower
US3073455A (en) Derrick
GB2043567A (en) Bridging apparatus for offshore structures
US3604745A (en) Toggle arm clamp for lift trucks
US2248794A (en) Ladder utility vehicle
US2778694A (en) Mobile swinging lift platform equipment
US2919107A (en) Folding boom