US3616894A

US3616894A - Accumulation section for a conveyor

Info

Publication number: US3616894A
Application number: US844792A
Authority: US
Inventors: Wolfgang Koennecke; Reinhold Stricker
Original assignee: Flughafen Frankfurt am Main AG
Current assignee: Flughafen Frankfurt am Main AG
Priority date: 1968-08-01
Filing date: 1969-07-25
Publication date: 1971-11-02
Anticipated expiration: 1988-11-02
Also published as: NL6907493A; GB1230918A; FR2014824A6

Abstract

The invention relates to a conveyor system in which a series of pallets are moved on rails by means of individual driving wheels spaced along the track for frictional engagement with the underside of the pallets; a lever system is used to engage the individual wheels with a common belt drive power source or to brake the individual wheels when not being driven.

Description

United States Patent 72] Inventors Wolfgang Koennecke Bad Hamburg Vor-der Hohe; Reinhold Stricker, Frankfurt am Main, both of Germany [21] Appl. No. 844,792

[22] Filed July 25,1969

[45] Patented Nov. 2, 1971 [73] Assignee Flughafen Frankfurt am Main Aktiengesellschaft Flughafen Frankfurt am Main, Germany [32] Priority Aug. 1, 1968 [33] Germany [54] ACCUMULATION SECTION FOR A CONVEYOR 6 Claims, 4 Drawing Figs.

[52] U.S. Cl

res/127 [51] Int. Cl 865g 13/02 [50] Field of Search 198/127 [56] References Cited UNIT ED STATES PATENTS 2,940,550 6/1960 Mathews 188/74 3,451,527 6/1969 Leach 198/127 Primary Examiner-Edward A. Sroka Attorney-Christen and Sabol ABSTRACT: The invention relates to a conveyor system in which a series of pallets are moved on rails by means of individual driving wheels spaced along the track for frictional engagement with the underside of the pallets; a lever system is used to engage the individual wheels with a common belt drive power source or to brake the individual wheels when not being driven.

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SHEET 2 OF 2 ACCUMULATION SECTION FOR A CONVEYOR This invention relates to an accumulation section for a pallet conveyor comprising drive wheels which normally act on the underside of the pallets, which are mounted on support rails and which are set in rotation by V-belts, wherein the drive wheels may have one special drive per support rail, to act on the V-belts, according to our copending Pat. application Ser. No. 844,795, filed concurrently with this application, entitled "Pallet Conveyor.

In front of loading stations or deflectors in conveyors socalled accumulation sections are required, where approaching pallets are brought to a standstill in such a way that they either touch one another or stop a short distance away from one another.

The different forms of such accumulation sections are commercially available, but for conventional roller conveyors. In one system, the rollers are driven by a rubberband on their underside. The whole length of the band may be lowered, so that no further drive is imparted to the rollers. The disconnection of the drive is initiated by a lever with an attached feeler roller, which is controlled by a first pallet.

In the other system, in which rollers are driven at the sides by V-belts, the drive for the V-belt is provided below the actual conveyor track by means of a frictional wheel adjacent a motor. When one pallet has been decelerated, the frictional wheel is lifted off the motor by means of a lever with a feeler roller, so that the rollers can no longer be driven. A brake acting laterally on the rollers is also provided, its action depending on the weight of the pallets above it.

In the other accumulation section described in German Pat. Specification No. 1,138,693 pallets which have a lateral rim and which are conveyed on a rubber belt, are raised by wheels engaging laterally below the rims of the pallets, when the pal lets have to be stopped, for example before a deflector.

The disadvantage of these accumulation sections is that they only permit slight deceleration, partly because of the low friction of the pallets on the iron rollers, and partly because the drive itself is not designed for great deceleration. A disadvantage of the commercial systems is that many components project considerably from the profile of the track towards the foundation, particularly the drive motors for the rubber belts and the frictional wheels for the V-belt drive.

According to the present invention, the V-belt drive may be disconnected at the shaft of the drive wheels.

in the accumulation section according to the present invention the elements which interrupt the flow of power to the drive wheels-being provided actually on the drive wheel in question are accommodated within the profile of the track between the two support rails.

in a surprisingly simple apparatus of this type, comprising V-belts extending continuously over a plurality of drive wheels and arranged to be pressed onto V-belt pulleys by tensioning pulleys, the tensioning rollers are both arranged on a lever which may be pivoted out of the position in which it presses the belt against the pulley, in order to disconnect the drive, and an additional lifting roller is provided on the lever to lift the upper run of the belt offthe pulley.

It is advisable for the lever to be connected to the shaft of the drive wheel. This dispenses with the bearing for the lever, which would otherwise be necessary.

It is equally possible for the drive for the drive wheel to be disconnected by means of a clutch provided on its shaft, particularly a single-plate clutch.

An embodiment of this type may also be accommodated within the profile of the track.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

FIG. 1 shows the construction of a drive wheel for an accumulation section according to the invention with a belt-tensioning roller provided on an articulated lever;

HO. 2 shows a drive wheel provided with a single-plate clutch;

FIG. 3 is a front elevation of a drive wheel which can additlonully be braked; and

FIG. 4 is a plan view of part of FIG. 3. X

In FIG. 1 a drive wheel 2 is overhung mounted on a support rail 1 by an axle. A pulley 5 for a V -belt 3 is also provided on the shaft. The drive wheel 2 is rotated by the belt 3 and pulley 5, and the pulley 5 is accordingly frictionally connected to the wheel 2.

A lever 69 is also pivoted to the said shaft. It is arranged to pivot about a transverse axis 68 which coincides with the Ian gitudinal axis of the first-mentioned axle.

The lever 69 carries belt-

tensioning rollers

70 and 71 respectively, at each end. The roller 70 urges the lower run 3 of the V-belt 3 into frictional connection with the pulley 5, while the roller 71 urges the upper run 3" into frictional connection with the pulley 5. The lever 69 is additionally provided with a lifting roller 72, which is arranged below the upper run 3". When the

tensioning rollers

70, 71 are moved downwards and upwards respectively by means of the lever 69, the lifting roller 72 raises the upper run 3" into a position in which the frictional connection is released, thereby ensuring that the run 3" is definitely freed from the pulley 5. During the pivoting movement of the lever 69 which releases the frictional connection, the lower run 3 moves away from the V-belt pulley 5 by gravity, to a greater or lesser, but :in any case sufficient, extent. The lever 69 is displaced or pivoted, by means of a rod 67 which is pivoted to another arm thereof, although the rod 67 and lever 69 may, of course, be connected by methods other than that illustrated.

In FIG. 1 the V-belt 3 is shown in broken lines in the position where it extends over a plurality of pulleys 5 of drive wheels 2 with a frictional connection, and is shown in solid lines in the position where the connection between the pulley 5 and the belt 3 is released.

When the drive roller 2 is to be driven, the lever 69 is moved into the broken line position by the force of a spring 73, so that the V-belt 3 is guided onto the pulley 5 by the spring bias. The spring 73 bears on the stop 74.

FIG. 2 shows a single-plate clutch between the V-belt pulley 5 and a drive sprocket 8, as a further example of the disconnection of the driving force and the drive wheel 2 according to the invention. That portion of the clutch illustrated above the central section line of FIG. 2 is shown disengaged and is shown engaged below the section line of HO. 2. The pulley 5 is again fixed to the drive wheel 2. The vertical position of the lever 74' (dotted lines) corresponds to the locked state, and its inclined position (solid lines) to the uncoupled state.

The lever 74, together with a shaft 74" and a lever member 74", forms a rigid component mounted on a support 75. The member 74 is linked by a fulcrum pin 76 to a lever 77, which carries a pin 78 at the other end. A shaft 79, on which the drive wheel 72 is mounted on the support rail 1, also displaceably supports a sliding member 80. The latter acts, by means of a ball bearing 81, on a spring 82, having a disc 83 which is applied to the sprocket 8. A clutch lining 84 is provided on the opposite side of the sprocket; in the engaged condition it cooperates with a surface of the V-belt pulley 5.

If the drive for the drive wheels provided with clutch elements according to the invention is interrupted as described above-as is the case with the drive wheels in an accumulation section-the pallets 18 being conveyed over them come to a standstill.

FIG. 3 shows a brake which is mounted on part of the pulley 5 not contacted by the V-belt 3. It is actuated by a bar 65 connected to an arm 86. The arm 86 is, in turn, linked by a bearing 87 to the support rail 1. At the opposite end it is also fixed to a brake shoe 88 having an arcuate wearing surface 88'. The shoe is drawn back into its release position by a spring 89, so that the bar has to be compression loaded in order to engage the brake.

As illustrated in FIG. 4, the brake shoe wearing surface 88' is wedge shaped, so that it can fit snugly into the wedgeshaped groove in the V-belt pulley 5. When the brake comes into action, the drive wheel 2 is braked, since it is fixedas already mentioned-to the pulley 5.

The brake illustrated in FIGS. 3 and 4 may be provided on the drive wheels shown in FIGS. 1 and 2. But it is quite possible as illustrated not to provide all the drive wheels 2 with such brakes. Care must then be taken, however, to ensure that the brakes are distributed over the individual wheels 2, in such a way that out of the wheels supporting a pallet there is always one which has a brake. Operation of the lever 69 and the clutch in FIG. 2 is preferably synchronized with that of the brake in FIGS. 3 and 4. This can be done either by stopping the first pallet 18 to arrive at an accumulation section by manually operating the lever 69 and clutch in FIG. 2, i.e., purely mechanically, and then-with the first pallet 18 stationary-by stopping the successive pallets through actuation of switches by the first pallet 18, causing the successive levers 69, clutches and brakes to be set in operation. It is possible, however, for the first pallet 18 also to be stopped by electrical control means and for the succeeding pallets to be halted as described.

We claim:

I. In an accumulation section of a pallet conveyor system of the type wherein a plurality of individual pallets are separately supported on and moved by a series of drive wheels longitudinally spaced along a set of horizontal rails by means of common drive V-belt means extending along said set of rails and normally arranged to impart rotation to all of said drive wheels, the improvement comprising coupling means for at least one of said drive wheels, said coupling means including V-belt pulley means, means to rotatably mount said V-belt pulley means for operative engagement with said driven V- belt means and to rotate said one of said drive wheels when in said operative engagement, said V-belt pulley means including clutching and braking means movable between first and second positions, said clutching means including roller means to urge the belt means into engagement with the pulley means when in said first position and to allow the belt means to disengage from the pulley means when in said second position, said braking means including friction means movably mounted to engage with said pulley means when said clutching and braking means is in said second position.

2. The invention defined in claim 1, wherein said coupling means includes a shaft for said drive wheel and a V-belt pulley attached to said shaft, said belt means includes a horizontally extending V-belt for engagement with said pulley, and said clutching means includes pivoted lever means including a roller for engagement with said V-belt for tensioning the belt into driving engagement with the pulley when the lever means is urged in one direction, and a second roller mounted on the lever means for engagement with the belt for urging the belt out of engagement with the pulley when the lever means is urged in the opposite direction.

3. The invention defined in claim 2, wherein said lever means is pivotally mounted on said shaft for the drive wheel.

4. The invention defined in claim 1, wherein said coupling means includes a shaft for supporting one of said drive wheels and a pulley means rotatably supported on said shaft, said pulley means being in operative engagement with said driven belt means, said clutch means including a driven plate connected with said drive wheel and a driving plate connected with said pulley means, said clutch means also including means for axially shifting one of said plates into and out of operative engagement with the other of said plates.

5. The invention defined in claim 4, wherein said clutch means also includes articulated lever means connected with said one of said plates for said axial shifting thereof.

6. The invention defined in claim 1, wherein said coupling means includes a V-belt pulley rotatably mounted on said horizontal rails and operatively connected with a drive wheel, and said braking means includes a wedge-shaped element and means for shifting said wedge-shaped element into frictional engagement with the V-belt pulley.

Claims

1. In an accumulation section of a pallet conveyor system of the type wherein a plurality of individual pallets are separately supported on and moved by a series of drive wheels longitudinally spaced along a set of horizontal rails by means of common drive V-belt means extending along said set of rails and normally arranged to impart rotation to all of said drive wheels, the improvement comprising coupling means for at least one of said drive wheels, said coupling means including V-belt pulley means, means to rotatably mount said V-belt pulley means for operative engagement with said driven V-belt means and to rotate said one of said drive wheels when in said operative engagement, said Vbelt pulley means including clutching and braking means movable between first and second positions, said clutching means including roller means to urge the belt means into engagement with the pulley means when in said first position and to allow the belt means to disengage from the pulley means when in said second position, said braking means including friction means movably mounted to engage with said pulley means when said clutching and braking means is in said second position.