High-temperature Vacuum Pickup

Abstract

A high-temperature vacuum pickup apparatus is provided having a vacuum head, a depending elastomeric ring surrounding the head and sealingly attached and a sheet of a material selected from the group consisting of heat-reflecting and heat-retarding materials and combinations thereof surrounding and covering the elastomeric material.

Description

This invention relates to high-temperature vacuum pickup apparatus and particularly to a vacuum lift device for handling sheet metal at high temperature.

The use of vacuum devices for lifting articles is not new. Vacuum cups have been used for handling cold sheets of steel, aluminum, and similar materials for many years. All attempts to use these devices to handle high-temperature metal strip have proven to be unsuccessful. It has been recognized that handling strip particularly such as aluminum strip which is easily deformed and damaged would best be done by vacuum pickup devices if one could be found which would operate satisfactorily at the high temperatures which occur in hot rolled products. These temperatures are in the neighborhood of 800.degree. F. and upwards. Many attempts have been made to use vacuum pickup devices where the resilient member which makes contact with the metal has been carefully selected from various resilient materials but to no avail. For example, it has been attempted to use silicon rubber materials, however, these break at about 700.degree. F. and give off phosgene gas. As a result they have not been satisfactory. Neoprene has been tried, but this breaks down at about 500.degree. F. and the result is that the vacuum device is quickly destroyed and is no longer useful for the high-temperature sheets. I have discovered a structure which overcomes the problems of the prior art vacuum devices and which makes it possible to handle metal sheets at elevated temperatures heretofore not possible to be handled with a vacuum. I have found that by the insertion of a flexible thin layer of a heat-resistant or heat-reflectant material or a combination of heat-resistant and heat-reflectant materials over the surface of the vacuum pickup between the sheet to be picked up and the vacuum device makes it possible to pick up a metal sheet at a temperature which would ordinarily destroy the vacuum device.

In a preferred embodiment of my invention, I provide a vacuum head, a frustoconical depending elastomeric ring surrounding said head, a separate removable thin layer or sheet of a material selected from the group consisting of heat-reflecting and heat-resisting materials and combinations thereof surrounding the vacuum side of the head and the depending elastomeric material. Preferably the elastomeric material is neoprene or a silicone rubber. The heat-reflecting material is preferably a foil of metal such as aluminum foil or the like. The heat-resisting material is preferably a woven sheet of asbestos or similar heat-retarding material. The combination of heat-reflecting and heat-resisting materials is preferably a woven asbestos sheet faced with a thin aluminum foil fixed thereto. Preferably, the film or foil is attached to the head by means of tabs and a flexible cord running around the head above the depending elastomer ring.

In the foregoing general description of my invention, I have set out certain objects, advantages and purposes of my invention.

Other objects, advantages and purposes will be apparent from a consideration of the following description and the accompanying drawings in which:

FIG. 1 is an isometric view of a high-temperature vacuum pickup apparatus according to my invention partly in section with no vacuum applied;

FIG. 2 is a section through the apparatus of FIG. 1 under the vacuum.

Referring to the drawings, I have illustrated a sheet of hot rolled aluminum 10, a vacuum pickup head 11 having a vacuum valve 12, a depending neoprene ring 13 of generally frustoconical shape attached to the head 11 and surrounding the head, a sheet of woven asbestos 14 having an outer surface of aluminum foil 15 is provided between the aluminum sheet 10 to be picked up and the head 11 and depending ring 13. The sheet of asbestos 14 and foil 15 is provided with tabs 16 having grommets 17 through which an attaching cable 18 is applied so as to hold the sheet on the vacuum pickup.

When the device of this invention is used, the pickup 11 is placed over the sheet 10 to be picked up. Vacuum is applied to the valve 12 so as to draw a vacuum in the area beneath the pickup head 11 and the depending ring 13. In order to accomplish this, a hole 20 is formed in the protective sheet of asbestos 14 and aluminum foil 15 so that a vacuum can be drawn over the whole area beneath the protective sheet and above the sheet 10 to be picked up. The heat from the sheet 10 is thus isolated between the sheet 10 and the composite sheet made up of the sheet of woven asbestos 14 and the aluminum foil 15. Where a material such as woven asbestos is used, as in the embodiment illustrated, an additional amount of protection to the depending elastomer ring 13 is obtained as a result of a slight flow of cooling air between the elastomer ring 13 and the asbestos sheet 14 as a result of the woven nature of the sheet. While this is not positively essential to the operation of the apparatus, it is a highly effective auxiliary assistance in the cooling and protecting of the vacuum pickup and is preferred where very high temperatures are being experienced.

In the foregoing specification, I have set out certain preferred embodiments of my invention. The invention, however, may be embodied in other forms consistent with the foregoing description and the accompanying claims.

Claims

I claim:

1. A high-temperature vacuum pickup apparatus comprising a vacuum head, a depending elastomeric ring surrounding and sealingly attached to said head and a protective sheet of a material from the group consisting of heat-reflecting and heat-retardant materials which are heat resistant in the region of 800.degree. F. and includes a metallic reflector and combinations thereof surrounding and covering the elastomeric material.

2. A high-temperature vacuum pickup apparatus comprising a vacuum head, a depending elastomeric ring surrounding and sealingly attached to said head and a protective sheet in the form of a composite sheet of woven asbestos and aluminum foil surrounding and covering the elastomeric material.

3. A high-temperature vacuum pickup apparatus as claimed in claim 1 wherein the protective sheet includes a sheet of woven asbestos.

4. A high-temperature vacuum pickup apparatus as claimed in claim 1 wherein the metallic reflector is a sheet of metal foil.

5. A high-temperature vacuum pickup apparatus as claimed in claim 1 wherein the depending elastomer ring is made of neoprene.

6. A high-temperature vacuum pickup apparatus as claimed in claim 1 wherein the depending elastomer ring is a silicone rubber.