US 5,348,139 A · Counter-balanced pressure sensor for conveyor accumulation zone

Abstract

A counter-balanced pressure sensor for sensing a package carried by a belt-driven carrying roller conveyor includes a pivot support with a sensing roller attached. The sensing roller is deflected downward by the passage of the package on the conveyor, causing the pivot support to pivot downward, causing a feeler arm attached to the pivot support to contact a sensitive whisker valve mounted beneath the conveyor top surface. The conveyor includes a plurality of zones, all but one of which has one of the pressure sensors. When the pressure sensors in one or more succeeding zones detect the presence of a package in each of their associated zones, the belt drive in a preceding zone is disconnected from the rollers in that zone, putting the preceding zone into an accumulation mode. Each pressure sensor is sensitivity adjustable by adjusting a threaded connector for a counter balance positioned opposite the sensing roller on the pivot support. The pressure sensors are interchangeable with any of the conveyor carrying rollers so they can be positioned at any desired point along the conveyor.

Claims33

Dependent claims

A pressure sensing apparatus for sensing an object on a conveyor comprising:

(a) a two-sided support means which is pivotable about an axis which is positioned below the top surface of said conveyor;
(b) a first carrying roller rotatable about a shaft suspended between said two sides of said support means;
(c) a sensor means attached to said support means;
(d) biasing means for causing said support means to pivot to a position in which said sensor means is positioned just above said top surface of said conveyor, said biasing means comprising a counter balance which is threadably attached to a threaded rod at an opposite end of said support means from said sensor means, said counter balance being longitudinally adjustable along said threaded rod to thereby adjust the sensitivity of said sensor means;
and,
(e) said first carrying roller shaft also provides said pivot axis for said support means.

3 more elements

A conveyor apparatus, comprising:

(a) a plurality of zones including a charge zone, at least one intermediate zone, and a discharge zone;
(b) each said zone except the charge zone including at least one pressure sensing apparatus for sensing the presence of an object on said conveyor apparatus and a position sensing means;
(c) each said pressure sensing apparatus comprising:
(i) a support means which is pivotable about an axis which is positioned below the top surface of said conveyor;
(ii) a sensor means attached to said support means;
(iii) a counter balance positioned on said support means which counter balance causes said support means to pivot to a position in which said sensor means is positioned just above said top surface of said conveyor, said counter balance being threadably attached to a threaded rod at an opposite end of said support means from said sensor means, said counter balance being longitudinally adjustable along said threaded rod to thereby adjust the sensitivity of said sensor means;
and
(iv) a first carrying roller which is rotatable about a shaft which is positioned between said two sides of said support means, said first carrying roller shaft also forming the pivot axis for said support means.

5 more elements

A belt-driven conveyor apparatus for conveying objects in a first direction, comprising:

(a) a plurality of carrying rollers rotatable about a like plurality of shafts extending from side to side of said conveyor apparatus;
(b) an endless drive belt positioned beneath said carrying rollers, said belt being driven in a direction opposite to said first direction;
(c) at least one belt engaging friction means positioned beneath said belt, each said belt engaging means comprising a friction drive assembly including a plurality of roller means attached to a pair of side plates, said side plates being pivotably attached to said conveyor apparatus via two pairs of pivot arms, each said friction drive assembly including said roller means and said side plates being pivotably movable between a first position in which said belt is urged into contact with said carrying rollers and a second position in which said belt is withdrawn from contact with said carrying rollers, said friction drive assembly pivoting with said pivot arms such that said side plates and said roller means are substantially parallel with said endless drive belt in both said first and said second positions;
(d) at least one pressure sensing means for detecting the presence of an object on said conveyor apparatus;
and
(e) means for moving said friction means between said first and second positions in response to detection of said object by said pressure sensing means.

3 more elements

A belt-driven roller conveyor apparatus divided longitudinally into a plurality of zones including a charge zone, at least one intermediate zone, and a discharge zone, said conveyor apparatus conveying objects in a first direction and comprising:

(a) a plurality of carrying rollers within each zone, each said carrying roller being rotatable about a corresponding shaft extending from side to side of said conveyor apparatus;
(b) an endless drive belt positioned beneath said carrying rollers, said belt being driven in a direction opposite to said first direction;
(c) a belt engaging friction means positioned beneath said belt in each zone, each said friction means being movable between a first position in which said belt is urged into contact with said carrying rollers and a second position in which said belt is withdrawn from contact with said carrying rollers;
(d) a respective pressure sensing means for sensing an object positioned within each zone except the charge zone, each pressure sensing means comprising;
(i) a two-sided support means which is pivotable about an axis which is positioned below the top surface of said conveyor apparatus, said axis being formed by the shaft of a specially adapted one of said carrying rollers;
(ii) a sensing roller rotatable about said carrying roller shaft which sensing roller is suspended between said two sides of said support means;
and
(iii) an adjustable counter balance which causes said support means to pivot to a position in which said sensor means is positioned just above said top surface of said conveyor apparatus, said adjustable counter balance, said counter balance being threadably attached to a threaded rod at an opposite end of said support means from said sensor means, said counter balance being longitudinally adjustable along said threaded rot to thereby adjust the sensitivity of said sensor means, whereby said pressure sensing means can be adjusted to respond to objects of differing weights;
and
(e) positioning means within each zone for moving a corresponding one of said friction means between said first and said second positions, the positioning means in each of said zones except said discharge zone being responsive to detection of a said object by at least one of said pressure sensing means to move the corresponding friction means to said second position.

7 more elements

A accumulating conveyor apparatus including a plurality of separate conveyor zones, said apparatus comprising:

(a) a pressure sensing means positioned in at least one of said zones for detecting the presence of an object in said at least one zone, said pressure sensing means including an arm which is positioned for engaging a corresponding spring actuator in response to said presence;
(c) a plurality of carrying rollers in each zone, said carrying rollers being selectively driven by an endless belt;
(d) a belt engaging friction drive means being moveable between a first position in which said belt is urged into contact with said carrying rollers and a second position in which said belt is withdrawn from contact with said carrying rollers whereby when said friction drive means is in said second position, an associated conveyor zone or zone portion is placed into an accumulation mode;
(e) said whisker valve being connected to a means for positioning said friction drive whereby said friction drive is moved to said second position in response to opening of said whisker valve.

1 more element

A conveyor comprising:

(a) a plurality of zones including a charge zone, at least one intermediate zone, and a discharge zone;
(b) each said zone except the charge zone inlcuding at least one pressure sensing apparatus for sensing the presence of an object on said conveyor apparatus and a position sensing means;
(c) each said pressure sensing apparatus comprising:
(i) a support means which is pivotable about an axis which is positioned below the top surface of said conveyor;
(ii) a sensor means attached to said support means;
(iii) a counter balance positioned on said support means which counter balance causes said support means to pivot to a position in which said sensor means is positioned just above said top surface of said conveyor;
and
(iv) a first carrying roller which is rotatable about a shaft which is positioned between said two sides of said support means, said first carrying roller shaft also forming the pivot axis for said support means;
(d) a pair of opposing side rails and a plurality of second carrying rollers, each of which is rotatable about a shaft which is suspended between said side rails, said conveyor being adapted to convey objects hereon in a direction of conveyance perpendicular to the longitudinal direction of said second carrying roller shafts;
(e) a drive belt positioned beneath said second carrying rollers, said drive belt being driven in a direction opposite to said direction of conveyance, said belt being selectively urged into contact with said second carrying rollers to rotate said second carrying rollers to rotate said second carrying rollers;
(f) each of said first carrying rollers with said support means pivotally attached thereto being interchangeable with any of said second carrying rollers whereby each said pressure sensing apparatus can be located at any desired point along said conveyor;
(g) at least one belt engaging friction means positioned within each said zone, each said friction means being movable between a first position in which said belt is urged into contact with said carrying rollers and a second position in which said belt is withdrawn from contact with said carrying rollers;
whereby when one of said friction means is in said second position, the associated conveyor zone or zone portion is placed into an accumulation mode;
(i) positioning means for moving said friction means between said first and said second positions;
(j) the positioning means in each of said zones except said discharge zone being responsive to enabling of the position sensing means in at least the next succeeding zone to move the corresponding friction means into said second position;
(k) each of said positioning means comprising a pneumatic cylinder with a telescoping rod which is normally retracted but which is extended in response to charging said cylinder with air;
(l) each said telescoping rod being connected to a corresponding one of said friction means such that when said rod is extended, said friction means is placed in said first position, and when said rod is retracted said friction means is placed in said second position;
(m) each of said position sensing means comprising a normally closed whisker valve with a spring actuator which is positioned to be engaged by an arm on the corresponding pressure sensing means when said corresponding pressure sensing means is pivoted downward, thereby opening said whisker valve;
(n) each said whisker valve being connected to a limit valve in the preceding conveyor zone which limit valve is connected between a source of compressed air and the cylinder in one or more preceding zones, each said limit valve being normally open, but closed in response to opening of said whisker valve;
whereby
(o) compressed air is shut off from said cylinder in response to the engagement of said spring actuator by the pressure sensing means in one or more succeeding conveyor zones.

18 more elements

Dependencies are inferred from the claim text.

Counter-balanced pressure sensor for conveyor accumulation zone

Life of this patent

Counter-balanced pressure sensor for conveyor accumulation zone

Life of this patent

Abstract

Claims33