Suction Operated Lifting Device

Abstract

A device for lifting areal objects comprises a piston and cylinder arrangement which includes a piston rod extending from a cylinder for support by a lifting crane. The cylinder is connected to a suction disc by means of a pivotal ball joint. The suction line for the suction disc is characterized as a bore which extends from the cylinder through the ball joint and opens into a suction chamber defined on the underface of a suction disc which surrounds the bore.

Description

SUMMARY OF THE INVENTION

This invention relates in general to the construction of lifting devices and, in particular, to a new and useful suction operated lifting device which includes a piston and cylinder combination having a piston rod portion which extends through the bottom of the cylinder and is terminated in a ball joint which provides a pivotal mounting for a suction disc, the suction pressure being provided through a bore extending through the joint to the underside of the disc.

Device for lifting areal objects are known in various embodiments particularly those which consist of a cylinder piston arrangement with a piston rod which extends from the cylinder as an operating rod and which includes a suction disc connected to the cylinder bottom which is connected to the cylinder chamber through a suction line. In the known construction, the suction disc is made integral with the cylinder bottom which widens conically at its bottom to the diameter of the suction disc. The suction line consists of bores in the cylinder bottom and in the conical widening of the cylinder bottom. The devices of this type are quite satisfactory as long as they are small and are in the form of air pumps with suction discs which may be manipulated by an operator's hand. When the known devices are manipulated by hand, they can be attached accurately on the surface of an areal object to be lifted. But in the case of larger devices which must be manipulated by means of hoisting gears which are designed for lifting great loads, it is frequently not possible to accurately position the suction discs to lift the load safely. This is because the exact attachment on the surface of the areal object to be lifted which is necessary for the production of the necessary vacuum or underpressure is not readily possible. For receiving areal objects which are of great weight,the normal technical development would lead therefore to devices which are equipped with a plurality of suction disc and wherein the vacuum is produced by means of a pump. In these devices, the suction discs are articulated to traverses and have suction lines designed as hose lines, or similar means, which ensures that all the suction discs will be operative. The disadvantage of such devices is that they are complicated in their constructional design and they cannot be used when the loads to be lifted do not have a sufficiently large surface to permit the attachment of a plurality of hinged discs. In order to avoid these disadvantages, joints have threfore been arranged in devices of this type, which are located directly between the suction disc and the cylinder piston arrangement which supplies the suction pressure. For example, the suction disc is connected centrally to the cylinder bottom by means of a bore and socket joint and the suction line is designed as a flexible hose line. A disadvantage of this type of device is that the flexible hose line can interfere with the manipulation of the device and can become tangled or damaged and finally lead to inoperability and accidents which might lead to the object falling to the ground because of a damaged suction line.

In accordance with the present invention, there is provided a device for lifting areal objects which is characterized by a particularly simple and safe construction and which ensures the satisfactory manipulation of great loads. In accordance with the invention, a device for lifting areal objects comprises a cylinder and piston combination with a piston rod extending from the cylinder as a means for supporting the device for lifting and which includes a joint member which terminates in a pivotal ball joint which is connected to a suction disc member in a manner to permit the universal pivotal movement of the suction disc. In accordance with the inventive feature, the suction line is designed as a bore passing through the cylinder bottom and and the joint member and opening into the suction chamber defined on the underside of the suction disc. With such a construction, additional flexible hose line, as a suction line which connects to the cylinder, is not necessary. By defining the suction connection in the joint itself, there is a considerable saving in the requirement for the hose line and, in addition, the suction line is in a protected location not subject to any damage. The bore construction also provides a suction line which is always operative.

In the preferred arrangement of the invention, the pivotal joint for the suction plate comprises a ball and socket joint which includes a pivot ball member having a ball-shaped end which is secured to the bottom wall of the operating cylinder. A suction disc is made with a socket portion for receiving the ball end of the ball member. The suction bore passes through the ball member and the ball end thereof. The ball is advantageously retained at the underside of the suction disc member by a packing collar which bears upwardly against the ball. The collar is held in position by a sealing ring engaged within a groove of the underside cavity of the disc member. A feature of the construction is that a gasket is disposed within the cavity that is held in a vacuum sealing manner by two nut members which are engaged on a projection or an extension of the ball end of the ball member. The outer periphery of the gasket is secured to the suction disc member by a ring which fits into a recess defined on the underside of the suction disc. The gasket ensures that the suction chamber is sealed properly from the joint and thus from the cylinder bottom of the cylinder piston arrangement and from the atmosphere and thus ensures that an adequate under-pressure and finally a vacuum can be formed in the suction chamber cavity when the cylinder piston arrangement is operated. The construction ensures the continued adhesion of the areal object to be lifted to the suction disc and with a sufficient force. For this purpose, the ball end has a clamping means with oppositely acting clamping rings for clamping the inner periphery of the gasket, and the bore providing the suction pressure communication, passes through this clamping means. The clamping rings can also consist of a screw head of a hollow screw bolt to be screwed into the ball end of a check nut. The gasket is preferably secured on the suction disc itself by means of a clamping ring screwed thereon.

Of special significance also is the construction in which the suction disc is secured against rotation about its vertical hinge access or prevented from such rotations by means of at least one stop secured on the ball portion of the joint member or formed as an inner square ring which is secured on the cylinder bottom. This limitation of the rotary movement of the suction disc can also be achieved through a limiting sector of movement with a bolt connection secured on the ball and socket joint. This has the result that the gasket is not subjected to stresses which can damage the gasket during a long period of operation. Such an arrangement, nevertheless, permits the disc to perform any pivotal movement about the horizontal axis extending through the joint and it thus retains its freedom of movement necessary for the proper reception and attachment of an areal object to be lifted.

The advantages achieved with the invention are seen primarily in the fact that the device for lifting areal objects includes a suction disc which is connected through a joint to the cylinder piston arrangement and can therefore always be attached exactly on the object to be lifted and to bear on the object tightly on all sides. The construction also makes it possible to provide a suction connection which is in a protectable spot and eliminates the necessity for a flexible hose as a suction line. By arranging the suction connection to extend through a ball member, which provides a pivotal support for the suction disc, trouble-free and safe operation is assured, and no damages to the suction line are likely and, in addition, the suction line does not interfere with the manipulation of the device. The device also has the further advantage that it can be used for lifting great loads and can be manipulated with the hoisting gear.

Accordingly, it is an object of the invention to provide an improved suction operating device for lifting objects, which includes a piston and cylinder combination for producing a negative pressure and a ball joint member which is secured to the bottom of the cylinder and, which provides a pivotal support for a suction disc member and which also provides a connecting bore for the suction pressure to the underside of the disc member.

A further object of the invention is to provide a pivotal mounting for a suction disc on an operating fluid pressure cylinder which includes a ball member having a bore therethrough defining a suction pressure communication line and which provides a pivotal mount for a suction disc member, the suction disc member having a cavity beneath the ball which is sealed by a gasket held by clamping means secured to the ball at the inner periphery and by a clamping ring secured to the disc at the outer periphery of the basket.

A further object of the invention is to provide a lifting device which is simple in design, rugged in construction, and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference should be had to the accompanying drawing and descriptive matter in which there is illustrated a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWING

In the drawing:

FIG. 1 is a side elevational view partly broken away of a lifting device constructed in accordance with the invention; and

FIG. 2 is an enlarged partial sectional view of the operating mechanism of the device shown in FIG. 1.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawing in particular, the invention embodied therein comprises, a device for lifting an areal object 1, which includes a cylinder and piston combination, generally designated 2, and which includes an outer fluid type cylinder 4 in which is movable a piston member 4a, having an operating rod 3, which extends out of the cylinder at its upper end and terminates in an engagement eyelet 5 which may be carried by a lifting crane or similar device.

In accordance with the invention, the bottom 6 of the cylinder 4 is provided with a ball member or extension 11 which forms a pivot ball head in the form of a ball part 12 for universally pivotally supporting a suction disc 8. The articulated pivot joint 7 which is thus formed is defined by the ball head 12 in the interior wall 22 of the suction disc 8 and, in addition, the ball member 11 also defines a passage or bore 9 for communicating the suction pressure from the cylinder 4 to the underside of the disc 8 at the location of an interior central chamber 10. The communication passage 9 is thus located in an operably safe location. The underside of the spherical recess 22 which received the ball extends into a cavity 24 which is closed by a packing 13 having an inner spherical surface 13a and which is held in position by a packing ring 25. The packing ring 25 is fitted into a receiving groove 26 defined at the inner end of the cavity 24.

A gasket member 16 is clamped at its inner periphery by clamping means generally designated 17 which comprises a hollow screw bolt 18 which is screwed into the ball end 12 of the ball member 11 and an inner ring or check nut 19 which may be formed as part of the ball end 12. The gasket 16 divides the cavity 24 and defines the exterior suction chamber 10 at the underside of the disc 8. The bore 9 communicates at its lower end with the suction chamber 10. The outer periphery of the gasket 16 is sealed by a clamping ring 20 which is screwed to the suction disc 8, for example, by means of a threaded screw member 26 so that the chamber 10 is sealed by the gasket 16, in respect to the joint 7 and the atmosphere. This ensures that a negative or vacuum pressure condition can exist in the chamber 10 for holding the disc 8 to an article to be lifted.

The suction disc 8 is limited in its rotative movement on a vertical axis by stop means, generally designated 2, which is secured on the cylinder bottom 6 and which includes a ring 21a with a square cross-section or of a bolt connection 21b which is secured on a ball head 12. This limit to the rotative movement of the disc 8 is provided in order to prevent damage to the gasket 16.

When it is desired to lift an article, the disc 8 is merely placed over the article and suction is applied in the space 10 by the movement of the piston 4a and through communication to the suction space 10 via the passage 9. This suction may be produced merely by the upward movement of the piston rod portion 5 when it is engaged by a lifting device such as an overhead crane hook (not shown).

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

Claims

What is claimed is:

1. A lifting device comprising a fluid cylinder, a piston slidable in said cylinder and having a rod portion extending outwardly through the top thereof for engagement by a lifting device, a ball joint member connected to the bottom of said cylinder and having a lower ball-shaped end, a suction disc member having an interior ball-shaped receiving cavity engaged around the ball-shaped end of said ball member, a packing within said suction disc bearing against the underside of said ball-shaped end, a gasket seal having its inner periphery engaged with said ball-shaped member and its outer periphery engaged with said disc and defining on the underside of said gasket seal a suction cavity, said suction cavity being communicated by a passage through said ball member to the interior of said cylinder for communicating a suction pressure therethrough to said cavity upon movement of said piston within said cylinder, means for clamping said gasket seal to said ball member, and means adjacent said sealing disc for limiting the rotative movement of said sealing disc about a vertical axis, including a pin carried on said ball-shaped portion of said member and extending radially outwardly, said suction disc having a receiving cavity for said pin of a certain circumferential extent defining the limit of the path of movement of said disc.