Field service vehicle

Claim 2

A field service truck having a cab and bed to the rear of said cab comprising: track means supported by said truck at each side of said bed, boom means having hoist means supported at its upper end, boom support means pivotally mounted to the lower ends of said boom means and mounted on said track means for movement fore and aft therealong, said boom support means being free from transverse members in the vicinity of its lower end so that said bed is kept free from obstruction thereby and is capable of carrying a load that is unaffected by and does not affect the fore and aft movement of said boom support means, said boom means being able to swing up and down on the boom support means, due to the pivotal mounting, a boom winch supported by said bed in a stationary position adjacent said cab and having cable means connected to the upper end of said boom means for raising and lowering said upper end, a boom motor supported by said bed in a stationary position adjacent said cab and operatively connected to said boom winch for operating it, and a travel motor supported by said bed in a stationary position adjacent said cab and operatively connected to said boom support means for moving them fore and aft on said track means.

Claim 3

The field service truck of claim 1 having boom-retaining means connecting said travel motor to said boom winch at a ratio such that fore-and-aft movement of said boom means retains the upper end of said boom means at substantially the same height, so long as said boom motor is not simultaneously operated.

Claim 4

The truCk of claim 2 wherein said boom-retaining means comprises a drum and a shaft on which said drum is supported, said shaft being driven by said travel motor, said boom cable passing from said boom winch to said drum via said upper end of said boom means.

Claim 5

The truck of claim 2 wherein said boom-retaining means comprises differential means between said boom winch and said boom motor and between said boom winch and said travel motor.

Claim 6

The truck of claim 1 wherein said boom means comprises at least one telescopable leg for extension and retraction.

Claim 7

The truck of claim 1 wherein said track means are supported above said bed, so as not to interfere unduly with the holding capacity of said bed.

Claim 8

A field service truck having a bed to the rear of its cab, comprising a pair of tracks supported at each side of said bed, a boom comprising two converging beams with a hoist pulley at their upper meeting ends, boom support means pivotally mounted to the lower end of each said beam and free of transverse members therebetween and mounted on the tracks for movement fore and aft therealong, said boom being able to swing up and down on the boom support means, due to the pivotal mounting, said boom being movable fore and aft of said bed without interfering with a load on said bed and without being interfered with by such a load, a stationary boom winch secured to said bed near said cab and having cable means connected to the upper end of said boom for raising and lowering said upper end, a stationary boom motor secured to said bed near said cab and operatively connected to said boom winch for operating it, a stationary hoist winch secured to said bed near said cab and having cable means connected over said hoist pulley and having a hoist fixture thereon that is raised and lowered by said hoist winch, a stationary hoist motor secured to said bed near said cab and operatively connected to said hoist winch for operating it, and a stationary travel motor secured to said bed near said cab and operatively connected to said boom support means for moving them fore and aft on said tracks.

Claim 9

A field service truck having a bed to the rear of its cab, comprising a pair of tracks supported at each side of said bed, a boom comprising two converging beams with a hoist pulley at their upper meeting ends, boom support means pivotally mounted to the lower end of each said beam and free of transverse members therebetween and mounted on the tracks for movement fore and aft therealong, said boom being able to swing up and down on the boom support means, due to the pivotal mounting, said boom being movable fore and aft of said bed without interfering with a load on said bed and without being interfered with by such a load, a stationary boom winch secured to said bed near said cab and having cable means connected to the upper end of said boom for raising and lowering said upper end, a stationary boom motor secured to said bed near said cab and operatively connected to said boom winch for operating it, a stationary hoist winch secured to said bed near said cab and having cable means connected over said hoist pulley and having a hoist fixture thereon that is raised and lowered by said hoist winch, a stationary hoist motor secured to said bed near said cab and operatively connected to said hoist winch for operating it, and a stationary travel motor secured to said bed near said cab and operatively connected to said boom support means for moving them fore and aft on said tracks.

Claim 10

The field service truck of claim 7 having differential means connecting said travel motor to said boom winch and said hoist winch, connecting said boom motor to said boom winch, and connecting said hoist motor to said hoist winch, at ratios such that fore-and-aft movement of said boom retains the upper end of said boom at substantially the same height and retains the hoist fixture at substantially the same height, so long as said hoist motor and boom motor are not simultaneously operated.

Claim 11

The field service truck of claim 8 having means for intentionally operating said hoist motor while said travel motor is operating.

Claim 12

The field service truck of claim 8 having means for intentionally operating said boom motor while said travel motor is operating.

Claim 13

The field service truck of claim 7 having means for extending both of said boom legs simultaneously.

Claim 14

The field service truck of claim 7 having means for extending one leg of said boom a limited amount.

Claim 15

The field service truck of claim 7 wherein said truck bed has sidewalls and said tracks are supported above said bed by said sidewalls, so as not to interfere unduly with the holding capacity of said bed.

Claim 16

A field service vehicle having a cab and a bed to the rear of said cab, comprising: a boom comprising two converging beams meeting at an upper end with a hoist pulley at the upper ends of said boom, boom support means pivotally mounted to the lower end of each said beam, said boom being able to swing relatively to the boom support means and being free of transverse members so that said bed is left free for carrying a load, guide means at each side of said bed for guiding said boom support means fore and aft of said vehicle, first stationary power means secured to said bed near said cab and operatively connected to said boom for swinging the upper end Of said boom relative to its lower ends cable means connected over said hoist pulley and having a hoist fixture thereon, second stationary power means secured to said bed near said cab and connected to said cable means for raising and lowering said fixture, and third stationary power means secured to said bed near said cab and operatively connected to said boom support means for moving them fore and aft along said guide means.

Claim 17

A field service vehicle having a cab and a bed to the rear of said cab, comprising: a boom comprising two converging beams meeting at an upper end with a hoist pulley at the upper ends of said boom, boom support means pivotally mounted to the lower end of each said beam, said boom being able to swing relatively to the boom support means and being free of transverse members so that said bed is left free for carrying a load, guide means at each side of said bed for guiding said boom support means fore and aft of said vehicle, first stationary power means secured to said bed near said cab and operatively connected to said boom for swinging the upper end Of said boom relative to its lower ends cable means connected over said hoist pulley and having a hoist fixture thereon, second stationary power means secured to said bed near said cab and connected to said cable means for raising and lowering said fixture, and third stationary power means secured to said bed near said cab and operatively connected to said boom support means for moving them fore and aft along said guide means.

Claim 18

The vehicle of claim 14 having first differential means operatively connecting both said first power means and said third power means by different paths to said boom at a ratio such that during fore-and-aft movement of said boom the upper end thereof is maintained at substantially the same height and second differential means operatively connecting both said second power means and said third power means by different paths to said cable means at a ratio such that during fore-and-aft movement of said boom the hoist fixture is maintained at substantially the same height.

Claim 19

The vehicle of claim 14 wherein said vehicle has sidewalls on each side of said bed and said guide means are in said sidewalls.

Claim 20

A field service vehicle having a bed with sidewalls, comprising: a pair of guide means supported by said sidewalls, one at each side of said bed, and located above said bed so as not to interfere with the holding capacity of said bed, an A-frame boom comprising two converging beams and a hoist pulley at its upper end, boom support means pivotally mounted to the lower end of each said beam and mounted to said guide means for movement fore and aft therealong, a chain having its ends secured to opposite ends of each said boom support means, for moving said boom fore and aft, a boom winch having cable means connected to the upper end of said boom for raising and lowering said upper end, a boom motor operatively connected to said boom winch for operating it, a hoist winch having cable means connected over said hoist pulley and having a hoist fixture thereon that is raised and lowered by said hoist winch, a hoist motor operatively connected to said hoist winch for operating it, a travel motor operatively connected to said chains for moving said boom support means fore and aft on said guide means, a first differential connecting said travel motor and said boom motor by different paths to said boom winch at a ratio such that during fore-and-aft movement of said boom, the upper end of said boom is maintained at substantially the same height, and a second differential connecting said travel motor and said hoist motor by different paths to said hoist winch at a ratio such that during fore-and-aft movement of said boom, the hoist fixture is maintained at substantially the same height, provided neither said hoist motor nor said boom motor is simultaneously operated.

Claim 21

A field service vehicle having a bed with sidewalls, comprising: a pair of guide means supported by said sidewalls, one at each side of said bed, and located above said bed so as not to interfere with the holding capacity of said bed, an A-frame boom comprising two converging beams and a hoist pulley at its upper end, boom support means pivotally mounted to the lower end of each said beam and mounted to said guide means for movement fore and aft therealong, a chain having its ends secured to opposite ends of each said boom support means, for moving said boom fore and aft, a boom winch having cable means connected to the upper end of said boom for raising and lowering said upper end, a boom motor operatively connected to said boom winch for operating it, a hoist winch having cable means connected over said hoist pulley and having a hoist fixture thereon that is raised and lowered by said hoist winch, a hoist motor operatively connected to said hoist winch for operating it, a travel motor operatively connected to said chains for moving said boom support means fore and aft on said guide means, a first differential connecting said travel motor and said boom motor by different paths to said boom winch at a ratio such that during fore-and-aft movement of said boom, the upper end of said boom is maintained at substantially the same height, and a second differential connecting said travel motor and said hoist motor by different paths to said hoist winch at a ratio such that during fore-and-aft movement of said boom, the hoist fixture is maintained at substantially the same height, provided neither said hoist motor nor said boom motor is simultaneously operated.