Drive for moveable shield in luggage screening apparatus

• US 4,210,811 A
• Filed: 09/22/1978
• Issued: 07/01/1980
• Est. Priority Date: 11/03/1975
• Status: Expired due to Term

• Current Assignee: Heimann GmbH
• Original Assignee: Heimann GmbH
• Inventors: Dennhoven, Manfred, Kunze, Claus
• Primary Examiner(s): Smith, Alfred E.
• Assistant Examiner(s): Howell, Janice A.
• Application Number:
  US05/945,097
• Time in Patent Office: 648 Days
• Field of Search: 250/358 R, 250/359, 250/360, 318/135
• US Class Current: 378/57
• CPC Class Codes: G01N 23/04 and forming images of the material
• CPC Class Codes: G01V 5/20 Detecting prohibited goods, e.g. weapons, explosives, hazardous substances, contraband or smuggled objects

Abstract

An apparatus for inspecting or screening articles, such as closed luggage and parcels, having a moveable shield to enclose selectively a monitoring duct area in which the articles are placed for screening by X-ray or similar radiation. The shield moves in a fixed housing (which may in turn be mobile) on wheels. A linear drive motor has a stator fixed in the bottom of the housing. The shield carries a rail electromagnetically reactable directly with the stator. Proximity switches in the housing activated by a magnet on the shield control the travel of the shield. A switch located between the end of travel switches may be employed to vary the speed of the linear motor to provide quick, safe cycling of the apparatus.

Claims

1. In a radiation-screening apparatus for inspecting sealed articles such as parcels and luggage, including a moveable shield selectively enclosing a monitoring duct, and drive means for moving said shield with respect to a fixed housing of said apparatus, the improvement comprising wherein:

said drive means comprises;

an electromagnetically operable linear motor means having a rail and a stator, one of said rail and stator being attached to the shield and the other being fixed in the housing; and

motor control means connected to said linear motor means and to an electrical power supply, said control means including three proximity switches and an activator, said switches and activator being mounted to be moveable relative to each other, two of said switches comprising limit end switches terminating electrical power to drive said linear motor at opposite ends of travel of said shield and the third proximity switch comprising a braking switch reducing electrical power to said linear motor between opposite ends of travel of said shield.

2. In a radiation-screening apparatus for inspecting sealed articles such as parcels and luggage, which includes a moveable radiation shield selectively enclosing a monitoring duct and drive means for moving said shield between two terminal positions relative to a fixed housing of said apparatus, the improvement comprising wherein:

said drive means comprises;

an electromagnetically operable linear motor means having an electrically conductive rail and a stator, one of said rail and stator being attached to said moveable shield and the other being attached to said fixed housing; and

motor control means operationally connected to said linear motor means and to an electrical power source, said control means including a pair of electromagnetic proximity switches and an activating device, said proximity switches and activating device being mounted on said apparatus so as to be moveable relative to each other for at least terminating electical power to said motor means at said terminal positions of said shield.

3. In a radiation-screening apparatus as defined in claim 2 wherein said electrically conductive rail is attached to said moveable shield and said stator is attached to said fixed housing.

4. In a radiation-screening apparatus as defined in claim 3 wherein said electrically conductive rail is attached to said moveable shield via a flexible coupling member.

5. In a radiation-screening apparatus as defined in claim 2 wherein said control means includes at least a third proximity switch mounted on said apparatus so as to be moveable relative to said activating device, said third proximity switch decreasing electrical power to said motor means during shield movement between said terminal positions.