US3732743A

US3732743A - Extendable boom apparatus

Info

Publication number: US3732743A
Application number: US00123770A
Authority: US
Inventors: D Ballard
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-03-12
Filing date: 1971-03-12
Publication date: 1973-05-15
Anticipated expiration: 1990-05-15

Abstract

An extendable boom apparatus having a first boom member pivotally secured to and supported by a frame. A second boom member is pivotally secured at one end thereof to one end of the first boom member and is adapted to fold jack-knife fashion to a position parallel to the second boom member and, alternately, to an extended position in axial alignment with the second boom member. The alternate folding and extending of the apparatus is accomplished by means of a drive wheel, mounted on a transverse power driven shaft journaled in the end of the first boom member adjacent the second boom member, whose periphery is meshingly engaged with the arcuately shaped periphery of a plate fixedly secured to the second boom member. Apparatus is also disclosed which permits the drive wheel to be disengaged from the shaft so that the shaft is free to rotate within the drive wheel without imparting rotary motion thereto and thereby permitting the power driven shaft to be used for winch purposes.

Description

United States Patent 1191 Ballard [451 May 15, 1973 [5 4] EXTENDABLE BOOM APPARATUS [76] Inventor: Donald R. Ballard, Route 1 Box 310A, Sapulpa, Okla.

[22] Filed: Mar. 12,1971

[21] Appl. No.: 123,770

52 use! ..74/89.18,182/2 51 lnt.Cl ..Fl6h27/02 [58] FieldofSearch ..74/89.18,422,89.17,

[56] References Cited UNITED STATES PATENTS 3,610,058 7/1969 Mueller et al. ..74/89.17

509,665 11/1893 Jaquette 1 ..74/89.l8 3,289,695 12/1966 Thomaset al.... .....74/89.18

2,500,815 3/1950 Gerli ..l82/2 2,616,768 11/1952 Stemm r ..l82/2 2,988,163 6/1961 Foley ..l82/2 Primary Examiner-Allan D. Herrmann Assistant Examiner-Wesley S. Ratliff, Jr. Attorney- Dunlp, Laney, Hessin & Dougherty w I i 4a a 9f 1 70 [57] ABSTRACT An extendable boom apparatus having a first boom member pivotally secured to and supported by a frame. A second boom member is pivotally secured at one end thereof to one end of the first boom member and is adapted to fold jack-knife fashion to a position parallel to the second boom member and, alternately, to an extended position in axial alignment with the second boom member. The alternate folding and extending of the apparatus is accomplished by means of a drive wheel, mounted on a transverse power driven shaft journaled in the end of the first boom member adjacent the second boom member, whose periphery is meshingly engaged with the arcuately shaped periphery of a plate fixedly secured to the second boom member. Apparatus is also disclosed which permits the drive wheel to be disengaged from the shaft so that the shaft is free to rotate within the drive wheel without imparting rotary motion thereto and thereby permitting the power driven shaft to be used for winch purposes.

11 Claims, 8 Drawing Figures 70 O y y 1 EXTENDABLE BOOM APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to improvements in extendable booms and more particularly, but not by way of limitation to extendable booms used on truckmounted derricks for supporting workmens baskets and the like.

2. Description of the Prior Art The prior art discloses numerous schemes for mechanically extending derrick boom members. Generally these schemes require somewhat elaborate and expensive linkages and separate power sources or power take-offs. The prior art also discloses somewhat less expensive derrick structures which utilize manual effort to extend and fold the boom extensions attached thereto.

SUMMARY OF THE INVENTION The present invention defines an extendable boom apparatus which includes a base, and a first boom member, having a first end portion and second end portion, the first boom member being pivotally secured at the first end portion thereof to the base. A second boom member, having a first end portion and a second end portion, is pivotally secured at the first end portion thereof to the second end portion of the first boom member and is adapted to pivot to ajack-knife position adjacent and substantially parallel to the first boom member and, alternately, to pivot to an extended position in generally axial alignment with the first boom member. A shaft, having a first end portion and a second end portion, is transversely journaled in the second end portion of the first boom member. Rotating means is connected to the first end portion of the shaft for rotating the shaft. A drive wheel is secured to the second rotation of the shaft and drive wheel secured thereto in one direction causes a resultant rotation of the plate in the opposite direction thereby pivoting the second boom member from the jack-knife position to the extended position and, alternately, from the extended position to the jack-knife position.

An object of the present inventionis to provide an improved extendable boom apparatus for use on derrick structures.

Another object of the present invention is to provide an extendable boom apparatus for modifying a derrick structure having a manually extendable boom so that the boom may be extended mechanically without manual effort.

A further object of the present invention is to provide an extendable boom apparatus, which may be simply and easily installed in the field, for modifying a derrick structure having a manually extendable boom so that the boom may be extended mechanically without manual effort.

A still further object of the present invention is to provide an extendable boom apparatus which derives its power from the boom tip winch.

Another object of the present invention is to provide an extendable boom apparatus which is economical in construction and operation.

Other objects and advantages of the present invention will be evident from the following detailed description when read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation view illustrating the apparatus of the present invention in the folded jack-knife position.

FIG. 2 is a side elevation view illustrating the apparatus of the present invention in the extended position.

FIG. 3 is a schematic end view taken along lines 3-3 of FIG. 1, with portions of the second boom member broken away, more clearly illustrating the apparatus of the present invention.

FIG. 4 is a fragmentary side elevation view more clearly illustrating apparatus of the present invention in the extended position.

FIG. 5 is a fragmentary view taken along lines 55 of FIG. 4.

FIG. 6 is a fragmentary view similar to FIG. 5 illustrating an alternate embodiment of the present invention.

FIG. 7 is a fragmentary side elevation view similar to FIG. 4 illustrating another embodiment of the present invention.

FIG. 8 is a fragmentary view taken along lines 8-8 of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1, 2, 3, 4 and 5, and particularly to FIGS. 1 and 2, the apparatus of the present invention is generally designated by reference character 10. The apparatus 10 comprises a vehicle 12 such as a truck and an extendable boom 14 carried by the vehicle 12. The extendable boom 14 comprises a base 16 which is pivotally secured to the rear end 18 of the truck 12, and is adapted to pivot thereon about a vertical axis. A first boom member 20 is pivotally secured at the first end portion 22 thereof to the base 16 by pin connection 24, and is adapted to pivot thereon about a horizontal axis. A power cylinder 26 is pivotally secured at the first end 28 thereof to the base 16 by pin connection 30 and is pivotally secured at the second end 32 thereof to the lower medial portion 34 of the first boom member 20 by pin connection 36.

A shaft 38 is mounted transversely in the upper portion of the second end 40 of the first boom member 20. A second shaft 42 is transversely mounted in the lower portion of the second end 40 of the first boom member 20. A power driven boom tip winch 44 is mounted transversely on the second end 40 of the first boom member 20.

The power driven boom tip winch 44 comprises generally a winch drive motor 46 carried on one side of the first boom member 20, a winch shaft 48 transversely journaled in the second end 40 of the first boom member 20 and connected at the first end 49 thereof to the winch drive motor 46, and a winch reel 50 rigidly secured to the winch shaft 48. A winch line 52 is carried on the winch reel 50. The second end 54 of the winch shaft 48 extends a substantial distance beyond the first boom member 20 on the side opposite the winch drive motor 46. A hole 56 is formed in the winch shaft 48 normal to the axis thereof near the end 54 of the winch shaft 48. A hub 58 is carried on the winch shaft 48 adjacent the end 54 thereof. The hub 58 is sized such that it is free to rotate on the winch shaft 48. Two holes 60 are formed in the hub 58 in axial alignment normal to the axis of rotation of the hub 58. The

holes

56 and 60 are sized and positioned in the respective winch shaft 48 and hub 58 such that a locking pin 62 may be simultaneously passed through the

holes

56 and 60 thereby locking the hub 58 to the winch shaft 48 for rotation therewith. A double chain drive sprocket 64 is fixedly secured to the hub 58.

A second boom member. 66 comprises a boom section 68, a boot 70 fixedly secured to the first end portion 72 of the boom section 68, and a personnel bucket pivot shaft 74 carried by the boom section 68 adjacent the second end portion 76 of the boom section 68. Two hinge brackets 78 and two boom support legs 80 are formed on the boot 70.

The second boom member 66 is pivotally secured to the first boom member 20 by means of the two hinge brackets 78 which are journaled on the shaft 38 of the first boom member 20, and is adapted to pivot thereon about a horizontal axis. The second boom member 66 is adapted to pivot from a folded jack-knife position substantially parallel to the first boom member 20 to an extended position in substantial axial alignment with the second boom member 20. As illustrated in FIG. 4, when the second boom member 66 is in the extended position, the boom support legs 80) bear on the second shaft 42 of the first boom member 20. A locking pin 82 may be inserted through a hole 84 formed in the second end 40 of the first boom member 20 to retain the second boom member 66 in the extended position.

A plate 86 is fixedly secured to the boot 70 by four bolts 88. The plate 86 is spaced away from the boot 70 by four spacers 90 carried on the respective bolts 88. The plate 86 has an arcuately shaped peripheral portion 92. The are of the arcuately shaped peripheral portion 92 of the plate 86 is swung from the point of intersection of the plane of the plate 86 and the axial centerline of the shaft 38. A double drive chain 94 is welded to the arcuately shaped peripheral portion 92 of the plate 86. The pitch of the double drive chain 94 is identical to the pitch of the double chain drive sprocket 64. The double chain drive sprocket 64 is continuously meshingly engaged with the double drive chain 94.

A personnel bucket 96 is carried by the personnel bucket pivot shaft 74 near the second end portion 76 of the boom section 68. The personnel bucket 96 is carried by the personnel bucket pivot shaft 74 in a pendant position regardless of the position of the second boom member 66.

OPERATION OF THE PREFERRED EMBODIMENT To extend the second boom member 66 from its folded position as shown in FIG. 1, the power driven boom tip winch 44 is operated to lower the winch line 52 approximately 24 inches to 30 inches. The locking pin 62 is inserted through the holes 60 in the hub 58 and the hole 56 in the winch shaft 48. The hub 58 is then rigidly secured to the winch shaft 48. The power driven boom tip winch 44 is then operated in the opposite direction to raise the winch line 52 and at the same time rotate the hub 58 and the double chain drive sprocket 64 secured thereto in a clockwise direction, as

viewed in FIG. 1. The clockwise rotation of the double sprocket 64 causes a resulting counterclockwise rotation of the second boom member 66 about the shaft 38 through the meshing engagement of the double chain drive sprocket 64 with the double drive chain 94 mounted on the plate 86.

When the second boom member 66 has reached the fully extended position, as shown in FIGS. 2 and 4, the boom support legs 80 abut the second shaft 42. At this time, the power driven boom tip winch 44 is shut off. If it is desired to use the power driven boom tip winch 44 while the second boom member 66 is fully extended, the locking pin 82 should be inserted in the hole 84, thereby securing the second boom member 66 in the fully extended position. See FIG. 4. The locking pin 62 should then be removed from the winch shaft 48 and the hub 58, thereby allowing the winch shaft 48 to rotate freely within the hub 58 when the winch line 52 is raised or lowered.

To return the second boom member 66 from the extended position, as shown in FIG. 2, to the folded position, as shown in FIG. 1, the power driven boom tip winch 44 should be activated to raise the winch line 52 up to the reel 50. The locking pin 62 should again be inserted into the holes 60 in the hub 58 and the hole 56 in the winch shaft 48 thereby locking the hub 58 to the winch shaft 48. The locking pin 82 is then removed from the hole 84. The power driven boom tip winch 44 is then activated to lower the winch line 52 which in turn rotates the double chain drive sprocket 64 in the counterclockwise direction as viewed in FIG. 2. The counterclockwise rotation of the double chain drive sprocket 64 results in the clockwise rotation of the second boom member 66 about the shaft 38. When the second boom member 66 reaches the folded position, substantially parallel to the first boom member 20, the power driven boom tip winch 44 is shut off.

It should be noted that'if the power driven winch 44 is not to be used when the second boom member 66 is in its fully extended position, the locking pin 62 need not be removed from the hub 58 and the winch shaft 48, and the locking pin 82 need not be inserted in the hole 84 in the second end portion 40 of the first boom member 20.

DESCRIPTION OF THE EMBODIMENT OF FIG. 6

The apparatus illustrated in FIG. 6 is identical to the apparatus previously described for the preferred embodiment except that a single chain drive sprocket 98 is formed on the hub 58 which continuously and meshingly engages a single drive chain 100 which is welded to the plate 86. The apparatus of FIG. 6 finds application when the second boom member 66 is lightly loaded such as when no personnel bucket 96 is to be used therewith. The operation of the apparatus illustrated in FIG. 6 is identical to that described above for the preferred embodiment.

DESCRIPTION OF THE APPARATUS OF FIGS. 7 and 8 The apparatus of FIGS. 7 and 8 is identical to the apparatus previously described for the preferred embodiment except that instead of a double chain drive sprocket 64, a pinion gear 102 is carried by the hub 58 and is rigidly secured thereto. Gear teeth 104 are formed on the arcuately shaped peripheral portion 92 of the plate 86 and continuously and meshingly engage the teeth of the spur gear 102. The operation of the apparatus illustrated in FIGS. 7 and 8 is identical to that described above for the preferred embodiment.

From the foregoing, it will be apparent that the present invention provides an extendable boom apparatus which utilizes a power driven boom tip winch to extend and retract a previously manually extendable boom so that the boom may be extended without manual effort.

Changes may be made in the combination and arrangement of parts or elements as heretofore set forth in the specification and shown in the drawing without departing from the spirit and scope of the invention.

What is claimed is:

1. An extendable boom apparatus, comprising:

a base;

a first boom member, having a first end portion and a second end portion, said first boom member being pivotally secured at the first end portion thereof to said base;

a second boom member having a first end portion and a second end portion, said first end portion thereof being pivotally secured to the second end portion of the first boom member and being adapted to pivot to a folded jack-knife position adjacent and substantially parallel to the first boom member and, alternately, to pivot to an extended position in substantial axial alignment with the first boom member;

shaft means, having a first end portion and a second end portion, transversely journaled in the second end portion of the first boom member for rotating therein;

a drive wheel carried on the second end portion of the shaft means;

connecting means for securing the drive wheel to the second end portion of the shaft means for rotation therewith;

a plate fixedly secured to the first end portion of the second boom member, a portion of the periphery of the plate being arcuately shaped and continuously meshingly engaging the periphery of the drive wheel; and

drive means connected to the first end portion of the shaft means for drivingly rotating the shaft means and drive wheel secured thereto in one direction thereby drivingly rotating the plate in the opposite direction whereby the second boom member is pivoted from the folded jack-knife position to the extended position and, alternately, from the extended position to the folded jack-knife position.

2. An extendable boom apparatus as defined in claim 1 wherein the drive wheel may be disengaged from the shaft means so that the shaft means may be rotated independently without rotating the drive wheel.

3. An extendable boom apparatus as defined in claim 2 wherein the shaft means is a winch shaft.

4. An extendable boom apparatus as defined in claim 1 wherein the drive wheel is a chain drive sprocket and the arcuately shaped peripheral portion of the plate has a drive chain formed thereon which is meshingly engaged with the chain drive sprocket.

5. An extendable boom apparatus as defined in claim I wherein the drive wheel is a double chain drive sprocket and a double drive chain is formed on the arcuately shaped peripheral portion of the plate and is meshingly engaged with the double chain drive sprocket.

6. An extendable boom apparatus as defined in claim 1 wherein the drive wheel is a pinion gear and gear teeth are formed on the arcuately shaped peripheral portion of the plate, the pinion gear being continuously meshingly engaged with the gear teeth on the plate.

7. In combination with a truck-mounted extendable boom apparatus of the type wherein a base is pivotally mounted on the rear portion of a truck and is adapted to pivot about a vertical axis; a first boom member, having a first end portion and a second end portion, is pivotally secured at the first end portion thereof to said base and is adapted to pivot thereon about a horizontal axis; a second boom member, having a first end portion and a second end portion, is pivotally secured at the first end portion thereof to the second end portion of the first boom member and is adapted to pivot thereon about a horizontal axis to a folded jack-knife position adjacent and substantially parallel to the first boom member and, alternately, to pivot to an extended posi' tion in substantial axial alignment with the first boom member; a winch shaft, havinga first end portion and a second end portion, is transversely journaled in the second end portion of the first boom member with the second end portion of the winch shaft extending outwardly therefrom; and drive means is connected to the first end portion of the winch shaft for rotation thereof; the improvement comprising:

a drive wheel carried on the second end portion of the winch shaft;

connecting means for securing the drive wheel to the second end portion of the winch shaft so that driving rotation of the winch shaft and drive wheel secured thereto by the drive means in one direction thereby drivingly rotates the plate in the opposite direction whereby the second boom member is pivoted from the folded jack-knife position to the extended position, and, alternately, from the extended position to the folded jack-knife position.

8. An improved extendable boom apparatus as defined in claim 7 wherein the drive wheel may be disengaged from the winch shaft so that the winch shaft may be rotated independently without rotating the drive wheel.

9. An improved extendable boom apparatus as defined in claim 7 wherein the drive wheel is a chain drive sprocket and the arcuately shaped peripheral portion of the plate has a drive chain formed thereon which is meshingly engaged with the chain drive sprocket.

10. An improved extendable boom apparatus as defined in claim 7 wherein the drive wheel is a double chain drive sprocket and a double drive chain is formed on the arcuately shaped peripheral portion of the plate and is meshingly engaged with the double chain drive sprocket.

11. An improved extendable boom apparatus as defined in claim 7 wherein the drive wheel is a pinion gear and gear teeth are formed on the arcuately shaped peripheral portion of the plate, the pinion gear being continuously meshingly engaged with the gear teeth on the plate. I

Claims

1. An extendable boom apparatus, comprising: a base; a first boom member, having a first end portion and a second end portion, said first boom member being pivotally secured at the first end portion thereof to said base; a second boom member having a first end portion and a second end portion, said first end portion thereof being pivotally secured to the second end portion of the first boom member and being adapted to pivot to a folded jack-knife position adjacent and substantially parallel to the first boom member and, alternately, to pivot to an extended position in substantial axial alignment with the first boom member; shaft means, having a first end portion and a second end portion, transversely journaled in the second end portion of the first boom member for rotating therein; a drive wheel carried on the second end portion of the shaft means; connecting means for securing the drive wheel to the seconD end portion of the shaft means for rotation therewith; a plate fixedly secured to the first end portion of the second boom member, a portion of the periphery of the plate being arcuately shaped and continuously meshingly engaging the periphery of the drive wheel; and drive means connected to the first end portion of the shaft means for drivingly rotating the shaft means and drive wheel secured thereto in one direction thereby drivingly rotating the plate in the opposite direction whereby the second boom member is pivoted from the folded jack-knife position to the extended position and, alternately, from the extended position to the folded jack-knife position.

5. An extendable boom apparatus as defined in claim 1 wherein the drive wheel is a double chain drive sprocket and a double drive chain is formed on the arcuately shaped peripheral portion of the plate and is meshingly engaged with the double chain drive sprocket.

7. In combination with a truck-mounted extendable boom apparatus of the type wherein a base is pivotally mounted on the rear portion of a truck and is adapted to pivot about a vertical axis; a first boom member, having a first end portion and a second end portion, is pivotally secured at the first end portion thereof to said base and is adapted to pivot thereon about a horizontal axis; a second boom member, having a first end portion and a second end portion, is pivotally secured at the first end portion thereof to the second end portion of the first boom member and is adapted to pivot thereon about a horizontal axis to a folded jack-knife position adjacent and substantially parallel to the first boom member and, alternately, to pivot to an extended position in substantial axial alignment with the first boom member; a winch shaft, having a first end portion and a second end portion, is transversely journaled in the second end portion of the first boom member with the second end portion of the winch shaft extending outwardly therefrom; and drive means is connected to the first end portion of the winch shaft for rotation thereof; the improvement comprising: a drive wheel carried on the second end portion of the winch shaft; a plate fixedly secured to the first end portion of the second boom member, a portion of the periphery of the plate being arcuately shaped and continuously meshingly engaging the periphery of the drive wheel; and connecting means for securing the drive wheel to the second end portion of the winch shaft so that driving rotation of the winch shaft and drive wheel secured thereto by the drive means in one direction thereby drivingly rotates the plate in the opposite direction whereby the second boom member is pivoted from the folded jack-knife position to the extended position, and, alternately, from the extended position to the folded jack-knife position.

11. An improved extendable boom apparatus as defined in claim 7 wherein the drive wheel is a pinion gear and gear teeth are formed on the arcuately shaped peripheral portion of the plate, the pinion gear being continuously meshingly engaged with the gear teeth on the plate.