US2880942A - Safety device for brush hog - Google Patents

Description

April 1959 L. J. HALL SAFETY DEVICE FOR BRUSH HOG 2 Sheets-Sheet 1 Filed May 19, 1954 INVENTOR A/ewe/w J fla// (raw 0. M

flTTORNEY April 1959 L. 4 HALL 2,880,942 SAFETY DEVICE FOR BRUSH HOG Filed May 19, 1954 2 Sheets-Sheet 2 as 2282 77 I e2 73 75 78 6/ 64 72 v INVENTOR Hamel/3w J/m/l IYTTORNEY United States This invention relatesrftovbrushhogs :;and :particularly to. safety devicesfonbrush hogs :havingzrotatively driven .acuttergorchipper: heads.

An object ofa-.thisriinventionis', to 'provide sirnple and efiicient and easily operable, means-for very quicklyand easily stopping .the goperatiomofn-thewbrush :cutting element or headof a brush-:hog.

I Brush hogshaving 1 rotativelyt-driven; heads for =:com-

.minuting thebrush:aremsuallyimanually fed through approximately horizontal :feed; chutes *of relatively large size. ,-cluding.srnall. trees andllimbs up -to seven Or-eight inches in diameter. When ;this;material: is..-pushed 1 into the Thesetmachines :are designed; to; thog: zup brush infeed chute .and engaged by ,-.the rotating head it: is drawn with astrong pull into the machinesand, if aperson feeding the .machine should, become. caught :or. entangled in the .brush they could. be; pulledarinto; contact .zwiththe rotating head. Also.- it,-;sometimes=-happens that? wires,

.- stones, pieces of metal: :and .the: like will :inadvertently be fedinaalongt-with the :brushwand-vwillzdamage the machine.

An object of this invention" is :-to provide safety: means which isalways accessibleatoathe-person feeding the machine andby which the cutter head can and ordinarily will be. instantly :stoppedg-bythe operator in. case' of emergency.

Another object is to, provide-control meanswhich is instantly available.torthegoperatorbutwhichis positioned so that. it is notuliable .to. 'be contacted-and operated, by

the, materialbeing fd:,1'nt0?' the; machine; said control means being. on .topof the. feed chute: andwbeing protected from contact by. incoming brush by an overhanging edge of the feed. chute.

Another object of the-. invention. is to -providevsafety .devices in combination with abrush hog having a cutter head which. is vconnectedgthro ugh a clutchwithdriving 50 means, said safety-devicescomprising abrake connected with the cutter-head and positioned between the clutch and the cutter .head,ztogether-with a. clutchreleasing means and. a brake applying means. and manually operable control devices on=the-feed chute of the machine capable of instantly activatingthe clutch releasing means and the brake applying means to simultaneously release the clutch and applythe brake.

Other objects of thezinventionwill berapparent from the following description takenrinconnection' 'with the accompanying drawings.

Figure 1 is aview;inside elevation, with: parts in section, showing a brush hog having safety means "constructed in accordance with this invention.

- tion.

2,880,942 *Patented Apr. 7, 1959 ice 5 ofthe'safety devicesshown'in-Figs. l to 4 inclusive.

Fig. 6 is a diagrammatic view illustrating safety de- '-'-'vices similar to those shown in Figs. 1 to Sbutmodified *for actuation by compressed air.

Fig. 7* is afragmentaryviewpartlyin'elevation'and partly in'-'section"taken on'broker'rline 7"7 of Fig. 8

-andillustrating an e1ectric'-'brake 'and controh'means thereforapplied'to a'brush hog. I

5 Fig. 8' is a" fragmentarysectional-view-"of=the electric brake'devices shown iiiFig. 7.

T Fig. 9-isa fragmentary side-elevation 'of eleet'rically actuated clutch releasing means.

Fig 10 is aview similar to Fig. 9" showing the clutch releasing mean'sin a'difierent position, as itwould. appear 1 when the clutch is-"released.

Like-reference numerals designate like parts throughout the several views.

Referring to Figs. l'to 5; inclusive, =10indicates the frameand housing of abrush hog, ll'indicates arotatively driven cutter head in said'frame" and housing and -12 a substantially horizontal feed chute extending outwardly from the cutter head and through'which brush is fed into the 'machine. The feedchute 12'has'an upper 1 wall 13- which,"-outwardly considered, "is in clined' upwardly. Said upper wall: 13 terminates in a forward edgel l-Which serves as abrush guard for safety control devices; as-hereinafter explained.

'The cutter head 11' is driven from a -niotor15', shown in Fig." 2 and shown dia'grammatically'ili Fig. 5, through power t-ransmitting means which includes a clutch '17, an

intermediateshaft' "16 and a'driving connection,"such' as \l-beltmeans' 18 betweenthe-intermediateshaft 16and ashaft 28-on whichthe cutter head 11 is'mounted. A manually operated lever" 27, Figs. 2 and 5; isnormally 1 used'to engage and disengage'the'clutch '17. Emergency 0 clutch disengaging means constructed inaccordance with thisinvention'is also connected with the clutch" l7 and is operative to disengage said clutch and ho'ldthe "same disengaged. This emergency"clutch'disengaging means comprises a'fluidpressure cylinder 20 'having'therein a piston" 21 whiclr is connected by a piston rod 22*and rlever 23 with a clutch operating-shaft 24. The cylinder #20 is mountedhy a pivot '25 on atfixed support 26 and "has: a fluid pressure conduit '53 connected therewith; as

hereinafter explained.

This'isafety control means also embodiesbrake"mechanismonthe shaft'ZSof the driven cutter head 11. Said brake mechanism 'comprises a brakedrum' 29 rigidly attached to'the shaft "28, a brake band'30 extending around said-drum, brackets" 31"and32 rigid "with the respective :endportions ofsaid brake band, a tension rod 33' guided and'supportedin 'said'brackets, a cam 34 connected by a pivot 35*with' the tension rod 33'and means for imparting movement to'the cam 34 to tension the band 30 on the-drum 29. Anchor means36- connectsthe brake band'30 with I116 housing 10 ofthermzi'chine to resist torque and prevent rotary movement of the brake band. Also a guide and support member '37, rigid with the frame 10, is provided forthe tension rod 33.

-The cam moving-means shown in Figs. 1 and 5 comprises a fluid pressure cylinder 38 having therein a piston 39 which is connected by a piston rod 40 and pivot 41 withthe cam 34. A. pivot '42 conn'ects the outer end of the cylinder 38" with the-frame 10.

, A fluidpressure control valve comprising a-cylindrical v valve housing 43. having a' rotatable valve' member-'44 therein is :mounted byarsuitable bracket- 45 on the'top of the housing 10. The valve member 44 has four equidistantly spaced peripheral cavities 46, 46', 47 and 47. The opposite cavities 46, 46' are connected with each other by a passageway 48 and the other opposite cavities 47, 47' are connected with each other by another passageway 49 which is offset longitudinally of the valve member 44 relative to the passageway 48. Four conduits 50, 51, 52 and 53 are connected with the valve housing 43 at angular intervals, as shown in Figs. 3 and 4.

The conduit 53 is branched, as required, and is connected with both the clutch disengaging cylinder 20 and the brake applying cylinder 38. The conduits 52 and 51 are both connected with a fluid pressure reservoir or tank 54. The conduit 50, see Fig. 2, is connected with a pressure control valve 55 and said valve 55 is connected by a conduit 56 with a hydraulic pump 57 which is driven from the motor by suitable driving means 58, see Fig. 2. A conduit 59 connects the tank 54 with the pump 57.

The valve member 44 has a lever 60 attached to one end thereof. A push and pull type link 61 connects the lever 60 with a manually operable control or trip arm or plate 62. Preferably this control member 62 is a plate of substantial width which extends across a major portion of the feed chute 12. With a wide control member 62, if an operator should fall or be drawn toward the feed chute he will be substantially certain to contact and operate said control member and stop the machine. The control member 62 is pivotally mounted on the top wall of the feed chute 13 a short distance inward from the forward edge 14 thereof so it will be protected by the edge 14 from contact by incoming brush but will always be instantly accessible to the person feeding the machine. A bracket 63, secured to the top wall 13 of the feed chute carries pivot means on which the control arm 62 is mounted, this being pivot means 64. A tension spring 65 is connected between the control member 62 and a fixed frame part, such as the valve supporting bracket 45. This spring 65 is connected in such a manner as to cause the line along which it exerts a tension to cross from one side to the other of the center of pivot 64 when the control member is moved between the full line and the dotted line positions shown in Fig. 1. Thus the spring will yieldingly hold the control member 62 in either of these positions. Stops 61' may be provided on the valve housing 43 in the path of the lever 60 to limit the movement of both the valve member 44 and the control member 62.

When the control member 62 is in the position shown by full lines in Fig. 1 the valve 44 will be in the position shown in Fig. 3 and fluid can by-pass continuously from the reservoir 54, through conduit 59, pump 57, conduit 56, valve 55, conduit 50, cavity 47, passageway 49, cavity 47' and conduit 52 back to the reservoir 54. At the same time a relief passageway from both of the cylinders and 38 back to the reservoir 54 is open by way of the conduit 53, cavity 46' passageway 48, cavity 46 and conduit 51. Thus in this position of the valve member 44 the brake is released and the emergency clutch control means is neutralized and does not affect the operation of the clutch by the lever 27.

If the control arm 62 is pivotally moved to a position as shown by dotted lines in Fig. l the valve member 44 will be set in the position shown in Fig. 4. In this position said valve member will block off and close the passageways to the conduits 52 and 51 and will open a passageway from the pump 57, through conduit 56, valve 55, conduit 50, cavity 47, passageway-49, cavity 47' and conduit 53 to both of the cylinders 20 and 38. This simultaneously disengages the clutch 17 and applies the brake and instantly stops the machine. As long as the control member 62 remains in the dotted line position fluid pressure will be maintained in both of the cylinders 20 and 38 audit will be impossible to re-engage the clutch 4 17 by means of the manually operated lever 27. Obviously pressure regulated by-pass control means will be provided by the valve 55 so that excess fluid under pressure can return by way of a conduit 55' to the reservoir 54.

The apparatus diagrammatically shown in Fig. 6 illustrates means operated by compressed air for quickly stopping a machine of the type shown in Figs. 1 to 5. In the structure shown in Fig. 6 the cylinders 20 and 38 and the clutch and brake means and the cutter head and the parts connecting the cylinders 20 and 38 with the clutch and brake means respectively are all identical with those shown in Figs. 1 to 5 and insofar as they are shown they are correspondingly numbered. The pump 57 shown in Figs. 2 and 5 is replaced in Fig. 6 by an air compressor 70 of automatic loading and unloading type and this compressor 70 is driven, preferably by V-belt means 71 in a manner similar to the pump 57. The compressor 70 delivers compressed air through a conduit 69 to a reservoir 72. The reservoir 72 is connected by a conduit 73 with a valve 74 which is a modification of the previously described valve 43, 44 in that it is adapted to control a supply of compressed air. The valve 74 comprises a housing 75 having therein a rotatively movable valve member 76. The valve member 76 is provided with an operating lever 68 and has peripheral cavities 77, 77', 78 and 78. A passageway 79 connects the two cavities 77 and 77 and a similar passageway 80 connects the other two cavities 78 and 78'. The valve housing 75 has three angularly spaced ports 81, 82 and 83. The air pressure supply conduit 73 is connected with the port 81. A branched conduit 84 connects the port 83 with both of the cylinders 20 and 38. The port 82 is an exhaust port and can either be left open, as shown, or can have an exhaust pipe connected therewith. The valve 74 is mounted in a bracket like bracket 45 of Fig. 1 and the control means 62, 61, 65 which is connected with valve lever 68 is the same as shown in Figs. 1 to 5.

When the valve member 76 is in the position shown in Fig. 6 the cylinders 20 and 38 will both be open to exhaust by way of conduit 84 and valve passageways 77', 79, 77 and 82 and the valve will be closed as respects the passage of compressed air therethrough. Movement of the control member 62 to the dotted line position will move the valve member 76 clockwise far enough to block the exhaust port 82 and connect the air pressure supply conduit 73, by way of passageways 78, 80, 78' and 83 and conduit 84 to the two cylinders 20 and 38. This will instantly stop the machine by releasing the clutch and applying the brake.

The apparatus illustrated in Figs. 7 to 10 inclusive discloses electrically operated safety means for quickly and easily stopping rotation of a driven hogging member. The brush hog frame 90, cutter head 91, feed chute 92 with top wall 93 having forward edge 94, trip member or plate 95 and cutter head shaft 96 are similar to the corresponding parts described in connection with Figs. 1 to 5 inclusive. Also similar cutter head driving means is provided in the form of a motor 97 connected through a clutch 98 and shaft 99 and V-belt 100 with the cutter head shaft 96. The clutch 98 is normally controlled by a manually operated lever 101 which is connected with a clutch control shaft 102. An emergency lever 103 is also connected with the shaft 102. The outer end of the emergency lever 103 is pivotally connected with a link 104 which is provided with a hook 105. A compression spring 106 on the link 104 is supported by a fixed bracket 107 which is rigid with the motor housing. The spring 106 exerts, against a collar 108 on link 104, a pressure which tends to disengage the clutch 98 when the link 104 is disengaged from link holding means, as shown in Fig. 10. The link holding means comprises a latch member 109 supported from a fixed pivot 110 and having a hook 111 adapted to engage with the hook 105. A spring 112 yieldingly holds the latch member 109 in engagement with the hook 105 and a stop 113 limits movement in one direction of said latch member. A solenoid 114 is connected with the latch member 109 for releasing the same. When the solenoid 114 is energized it instantly releases the latch member and permits the spring 106 to disengage the clutch 98. Since the spring 106 holds the clutch 98 in engaged position it will be apparent that said clutch 98 can not be latched in an engaged position by the use of the clutch lever 101 as long as the solenoid 114 remains energized. This prevents re-engaging the clutch 98 until after the control member 95 has been reset in a neutral position after emergency operation.

If it is desired to disengage the clutch by the use of the lever 101 while the hooks 105 and 111 are latched the said hooks may be manually disengaged to permit this operation. When the solenoid 114 is de-energized and the hooks 105 and 111 are disengaged hook 111 will obviously snap into engagement with book 105 if the link 104 is moved downwardly by movement of lever 101.

The brake mechanism shown in Figs. 7 and 8 comprises a plate 115 fixed to the brush hog frame 90 and having a hub 116 within which the shaft 96 rotates. Brake band means 117 of internal type having brake lining 118 thereon is supported from the plate 115 and adapted to be expanded by a cam 123 to apply the lining 118 to a rotating brake drum 119. The drum 119 is secured by a hub 120 to the cutter head shaft 96. An electromagnet 121 is carried by a curved link 122 which is connected with the cam 123 so that when said link 122 is moved it will operate the cam 123 and apply the linings 118 to the drum 119. A spring 124 urges this brake means into released position. When the electromagnet 121 is energized it is attracted to a rotating armature disc 125 which is carried by the drum 119 and the force applied by this rotating disc to the electromagnet 121 angularly moves the curved link 122 and applies the brake.

The supply of current to the electromagnet 121 is controlled by a rheostat type of switch 126, Fig. 7. This switch is mounted in a housing 127 on the frame 90 and comprises a pivotally movable switch arm 128 connected with a lever 129. The lever 129 is connected by a link 130 with the control member 95. A spring 131, similar to the previously described spring 65, is provided to hold the control member 95 in either a neutral or an operative position.

The switch 126 controls the supply of electric current from a battery 132, which usually will be the battery of the motor 97, through a conductor 133, shown in each 6 ings clearly illustrate preferred embodiments of this invention but it will be understood that this disclosure is merely illustrative and that changes may be made within the scope of the following claims.

I claim:

1. In a brush hog a housing having a substantially horizontal feed chute, a cutter head in said housing; driving means connected with said cutter head; brake means operatively connected with said cutter head; brake applying devices connected with said brake means; a manually operable brake control member controlling said brake applying devices and pivotally mounted on the top of said feed chute a short distance inwardly from the outer end of the feed chute with said control member readily manually accessible from the intake end of the feed chute and shielded by the feed chute from contact with brush entering said feed chute; and a spring connected with said pivotally mounted brake control member yieldingly holding the same either in a brake released position or in a brake applied position.

2. In a brush hog, a housing having a substantially horizontal feed chute of generally rectangular cross sectional shape provided with a top wall under which brush entering said chute must pass; a cutter head in said housing; driving means connected with said cutter head; a clutch interposed in said driving means; clutch disengaging means connected with said clutch; brake means operatively connected with said cutter head; brake applying devices connected with said Make means; and a relatively wide upstanding emergency control member pivotally mounted on the exterior of the top wall of said feed chute a short distance inwardly from the outer end thereof and connected with both said clutch disengaging means and said brake applying means, said control member being manually accessible for a substantial distance crosswise of the feed chute and said control member being shielded by the forward edge of the chute from contact by incoming brush.

3. In a brush hog, a housing having a substantially horizontal feed chute of generally rectangular cross sectional shape provided with a top wall which is inclined downwardly from its outer toward its inner end and under which brush entering said chute must pass; a cutter head in said housing; driving means connected with said cutter head; a clutch interposed in the cutter head driving means; hydraulic fluid pressure supply means; a brake connected with said cutter head; hydraulic clutch releasing means connected with said clutch; hydraulic brake applying means connected with said brake; a valve controlling the supply of liquid under pressure from said fluid pressure supply means to said clutch releasing means and said brake applying means; and a valve controlling member pivotally mounted on the exterior of the inclined top wall of said FHA r-hnfz: q elwnrf distance. inwarrllv fmm the outer end

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