US3203535A - Gripping device - Google Patents

Description

1965 N. E. ELSAS 3,203,535

GRIPPING DEVICE Filed April 19, 1963 INVENTOR.

B /Vorman /sa$ United States Patent 3,203,535 'GRFPPENG DEVICE Norman E. Elsas, 31181 Maple Drive NE, Atlanta, Ga. Filed Apr. 19, 1963, set. No. 274,098 1 Claim. (Cl. '198'180) This invention relates to gripping devices and more particularly to a gripping device for conveniently gripping fabric, cardboard and other materials so that they can be transported or otherwise processed without dam age.

The processing of fabrics and other materials into garments and various other articles and items of manufacture frequently requires a gripping device for gripping and holding the material so that it may be automatically transported from one work location to another or so that work operations may be conveniently performed upon it at a work location. Many of these materials have irregularly textured surfaces which make them difficult to grip and hold firmly with previous gripping devices. This is because a rough or irregular surface provides so little effective surface for gripping that considerable mechanical pressure must be applied. The need for such pressure causes these previous gripping devices to be somewhat complicated and expensive and the mechanical pressure exerted by these previous gripping devices often damages the material.

The invention disclosed herein provides a convenient and effective device for gripping a variety of light weight materials so that they may be transported from one work location to another, so that processing operations may be performed upon them, or so that they may be stored or shipped. The invention is a gripping device comprising a bristle support having a plurality of bristles extending from it and a plate positioned parallel to the bristle support and engaged at an angle by the plurality of bristles. The bristles are reasonably flexible so as not to be easily broken. The material to be gripped by the gripping device is inserted between the bristles and the plate by a tucking blade, by hand or by any other suitable means. The plate holds the material against the tips of the bristles and the bristles grip the material so that it will not fall from the gripping means. Materials being held in the gripping device can be released from the gripping device by separating the bristles from the plate.

These and other features and advantages of the invention will be more clearly understood from the following detailed description and the accompanying drawings in which like characters of reference designate corresponding parts in all figures and in which:

FIG. 1 is a front elevational view of the gripping device used in combination with an overhead conveyor and shows the gripping device gripping a panel of fabric, cardboard or similar material for transporting along the conveyor.

FIG. 2 is a side elevational view of the gripping device as employed in the conveyor belt embodiment shown in FIG. 1 and as viewed in line 22 in FIG. 1.

FIG. 3 is a side elevational view of the gripping device used in combination with a continuous conveyor belt and a tucking blade.

FIG. 4 is a side elevational view of the gripping device used in combination with a reciprocating rod.

FIG. 5 is an enlarged sectional view of the gripping device.

These figures and the following detailed description disclose a preferred specific embodiment of the invention, but the invention is not limited to the details disclosed since it may be embodied in other equivalent forms.

This invention is most easily understood as a gripping device comprising a plate having a substantially flat material support surface 11 and a plurality of bristles 12 engaging the material support surface of the plate at an angle or. The plurality of bristles 12 extend from the bristle surface 14 of a bristle support 15, and each of the plurality of bristles 12 has its root 16 embedded in the bristle support 15 in known manner. The plurality of bristles 12 may be distributed individually over the bristle surface 14 or may be arranged in a plurality of tufts.

The bristle surface 14 of the bristle support 15 is substantially parallel to the material support surface 11 of the plate 10 and the plurality of bristles 12 extend parallel to one another between these two surfaces with the tip of each bristle lightly but firmly engaging the material support surface 11. The bristles 12 all extend at an angle, or, from the bristle support and form the same angle with the material support surface 11. The angle which each of the bristles 12 forms with the material support surface 11 results in the tip 18 of each bristle being displaced a fixed distance along the material support surface 11 from that point which each bristle 12 would engage if it were perpendicular to the material support surface. Since the bristles substantially are parallel to one another, the tips 18 of all the bristles 12 are displaced in the same manner, to the same degree, and in the same direction.

The direction in which the tips of all of the bristles 12 are displaced is the feed direction of the gripping device. This is because material inserted between the bristle support 15 and the plate 10 in the feed direction will simply bend the relatively flexible bristles 12 away from the plate 10. As a result, semi-rigid or rigid material such as cardboard can be readily inserted into the gripping device by simply inserting it between the bristle support 15 and plate 10 in the feed direction.

The direction opposite to the feed direction is the holding direction of the gripping device. This is because motion of material between the plate 10 and the tips 18 of the plurality of bristles 12 in this direction will cause the bristles 12 to bend toward the plate 10 so as to squeeze the material between the plate 10 and the tips 18 of the bristles 12. The squeezing action of the plurality of bristles 12 holds fabric, cardboard or any similar material between the plate 10 and the bristle support 15.

If the material being held is a fabric or other porous or irregularly textured material, the material is held because the tips 18 of the bristles 12 extend into the pores and irregularities of the material and move with the material as it tends to move in the holding direction. This motion of the tips 18 forces them more deeply into the material and causes the material to be tightly gripped both by a squeezing action and the combined rigidity of all bristles 12.

If the material being held is cardboard or some other relatively hard and non-porous material, the material is held because the friction between the tips 18 of the bristles and the material tends to move the tips 18 so as to force the tips 18 more firmly against the material. Whether the material is held by friction or actual insertion of the tips 18 of the bristles 12 into irregularities, the more the material tends to move in the holding direction, the more firmly the material is held. Material inserted in the gripping device can be removed from the gripping device without separating the bristles 12 from the plate 10 only by exerting sufiicient force to cause the tips 18 of the bristles 12 to come out of the irregularities of a textured surface, to overcome the friction between the tips 18 and the material, or to cause the bristles 12 to buckle and be displaced in the holding direction.

Whether the bristles 12 will buckle or permit a porous or non-porous material to slide between them and the plate is dependent upon the angle a at which the bristles 12 engage the plate 10 and the rigidity of the bristles 12. The angle or at which the bristles 12 engage the plate 10 and the rigidity of the bristles 12 are selected so that buckling of the bristles 12 will not readily occur and so that even though the material will slide from between the bristles 12 and the plate 10 before buckling occurs, considerable force must be applied by the weight of the material or other means to cause the material to slide from the holding device.

It has been found that nylon bristles between .075 inch and .2 inch in diameter, extending between /2 inch and 1% inches from the bristle support and forming an angle cc of approximately thirty degrees with the plate 10 are adequate for gripping and holding most relatively light materials such as fabrics or cardboard. The quantity of such materials which must be gripped by the gripping device varies from one application of the gripping device to another. However, the gripping device is best adapted to material in sheet form and as the size of each unit of material to be gripped increases, it is simply necessary to increase the number of bristles 12 and the area of the material support surface 11 engaged by the bristles 12. Thus, by selecting bristles 12 with the proper rigidity, selecting the proper angle or. at which the bristles 12 engage the plate 10, and the proper number of bristles 12 and area of the material support surface 11 engaged by the bristles 12, the invention may be embodied in a form suitable for gripping and holding most materials in sheet form and many materials with localized concentrations of weight.

Moreover, the gripping device can be used in a variety of embodiments. It can be used in embodiments where it is desired to insert material such as sheets of cardboard by hand into the gripping device for transporting to other locations. Once inserted, the cardboard will be held firmly enough to prevent its weight from causing it to pull from the gripping device.

The combination of the gripping device with an overhead conveyor as shown in FIG. 1 is suitable for such an application.

In such an embodiment, it is simply necessary to force a piece of cardboard 20 upward between the plate 10 and the bristle support 15 as each of a plurality of gripping devices moves in known manner along an overhead conveyor belt 21. The plurality of gripping devices are oriented so that the cardboard is inserted from below the conveyor belt 21 in the feed direction and so that gravity will tend to pull the cardboard 20 in the holding direction. When it is desired to remove the cardboard 20 from the gripping device, it is simply necessary to separate the tips 18 of the bristles 12 from the material support surface 11 by any known means. The bristles 12 and the efiective area of the gripping device between the tips 18 of the bristles 12 and the material support surface 11 are empirically selected so that in the absence of such separation, the resistance of the gripping device to the removal of the material will be sufiicient to prevent the material from being removed from the gripping device by any degree of force which would be reasonably encountered.

As shown in FIG. 3, the gripping device may also be used in a similar embodiment in combination with a tucking blade 22. The tucking blade 22 may be the edge of a tucking plate arranged to move in a reciprocating manner into and out of the space between the plate 10 and the bristle support 15 or it may be the side of a strip or roll to which reciprocal motion is imparted by a lever 24 pivotally mounted at a point 25. The gripping device may be one of a plurality of gripping devices carried in known manner by a conveyor belt 21 driven by a wheel and any known means may be used to impart pivotal or slidable motion to the tucking blade 22. The material 26 to be gripped by the gripping device is placed between the gripping device, oriented with its feed direction away from the material 26, and the tucking blade 22 in its withdrawn position. When the tucking blade 22 is moved toward the material 26 in a direction coinciding with the feed direction of the gripping device, the tucking blade 22 will carry the material 26 between the plate 10 and the tips 18 of the bristles 12. The bristles 12 engage the material 26 and not the tucking blade 22. Thus, when the tucking blade 22 is subsequently removed from between the bristle support 15 and plate 10, the material 26 remains in the gripping device where it is firmly gripped. The tucking blade 22 has a slick surface which causes it to slip easily from the material 26 as it withdraws from the gripping device.

In some embodiments of the gripping device it has been found convenient to mount the plate 10 and the bristle support 15 in pivotal relation to each other. In the embodiment shown in FIG. 3, the plate 10 is positioned at the end of an arm 28 having a vertical member 29 and the bristle support 15 is positioned at the end of an arm 30 pivotally mounted at the end of the vertical member 2?. The arm 30 is extended into a handle 31 which can be grasped to pivot the second arm 30 and move the bristle support 15 away from the plate 10. The plate 10 and bristle support 15 are urged toward each other by a spring 32 extending between the arm 28 and the arm 30.

In such an embodiment of the gripping device, the material 26 to be gripped is inserted into or removed from the gripping device when the bristle support 15 and plate 10 have been separated by using the handle 31. This is particularly necessary when the material 26 being gripped is a material such as a delicate fabric. Such a material does not have the rigidity to be forced between the bristles 12 and the plate 10 and will be torn or otherwise damaged if simply pulled from between the bristles 12 and the plate 10. The embodiment is also used where it is desired to grip only one of a plurality of layers of material 26. When the gripping device is embodied in such an arrangement it is moved in a reciprocating man ner toward and away from the edge of a pile of material 32 comprising a plurality of layers.

With each cycle of operation, the plate passes under the pile of material 32 and the bristle support 15 is raised by a cam bar 34 and passes above the pile of material 32. The cam bar 34 raises before the gripping device starts its motion away from the pile of material 32 and the bristles 12 drop under spring tension to engage the top layer of the pile of material 32. As the gripping device moves away from the pile of material 32, the tips 18 of the bristles 12 will engage the top layer of the pile of material 32 and draw it with the gripping device. The material support surface 11 of the plate 10 is relatively smooth and will not tend to draw with it the layer of material resting upon it. As a result, this embodiment of the gripping device will grip only the top layer of a pile of material and will draw this layer only from the pile of material.

Regardless of the specific arrangement of apparatus in which the gripping device is embodied, the gripping device provides a convenient and effective means for gripping materials without crushing or in any manner damaging the materials. The gripping device can be used in embodiments where the material has sufiicient rigidity to force itself into the gripping device; where the material is forced into the gripping device by a tucking blade, roller or hand; or where the device opens and closes on the material. However, in every embodiment of the gripping device, the gripping device will be completely safe to use since the bristles 12 will not injure the hand of an operator which may become caught between the plate 10 and the bristle support 14.

It will be obvious to those skilled in the art that many variations may be made in the embodiments here chosen for-the purpose of illustrating the present invention without departing from the scope therof as defined by the appended claim.

What is claimed as invention is:

A device for gripping a sheet of material, said device comprising, in combination, a plate having a substantially flat material support surface, said plate being positioned on one side of the sheet of material; a bristle support having a bristle surface substantially parallel to the material support surface of the plate, said bristle support being on the same side of the sheet of material as the plate; a plurality of parallel bristles, each bristle extending from the bristle surface and having its tip adjacent to a point on the material support surface and each bristle being the hypotenuse of a right triangle having as a first leg a line of reference perpendicular to the material support surface and as a second leg at line of reference parallel to the material support surface and extending between the first leg and the bristle; a tucking blade positioned on the opposite side of the sheet of material from the plate and having a plane of motion substantially parallel to the material support surface and which passes through the sheet of material and between the plate and the bristle support; and means for reciprocally moving the tucking blade in its plane of motion between a position more remote from the plate than the sheet of material and a position between the plate and the bristle support.

References Cited by the Examiner UNITED STATES PATENTS SAMUEL F. COLEMAN, Primary Examiner.

WILLIAM B. LABORDE, Examiner.

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