Slit-type sealing arrangement for encapsulated measuring system

• US 4,600,203 A
• Filed: 03/19/1985
• Issued: 07/15/1986
• Est. Priority Date: 03/24/1984
• Status: Expired due to Fees

• Current Assignee: Dr. Johannes Heidenhain GmbH
• Original Assignee: Dr. Johannes Heidenhain GmbH
• Inventors: Kraus, Heinz, Miller, Walter
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/713,481
• Time in Patent Office: 483 Days
• Field of Search: 33/125 R, 33/125 A, 33/125 C, 33/125 T, 277/DIG. 7, 277/237, 277/12, 277/32
• US Class Current: 277/345
• CPC Class Codes: G01B 3/002 Details
• CPC Class Codes: G01D 5/34769 Sealing means

Abstract

An encapsulated measuring system includes a follower coupled to a scanning unit which extends through a slit in a housing of the measuring system. This slit is sealed against lubricants and coolants by a pair of multipart sealing elements. Each multipart sealing element includes a sealing profile proper, along with a supporting element. The sealing profiles perform the sealing function, and the supporting elements provide the necessary permanent elasticity and stability of form. Because of this division of function, the sealing profiles themselves can be made of materials that are resistant to aggressive media such as lubricants and coolants, but themselves do not provide sufficient elasticity or stability of form to be used alone.

Claims

1. In an encapsulated measuring system for measuring the position of first and second objects movable relative to each other, of the type comprising a housing, adapted to be connected to the first object, which defines a slit extending along a measuring direction, a scanning unit disposed in the housing, and a follower, adapted to be connected to the second object and coupled to the scanning unit to move along the measuring direction and to extend through the slit, said follower having a convex shape in the measuring direction, the improvement comprising:

a pair of multipart sealing elements, each multipart sealing element mounted to the housing on a respective side of the slit to extend along the measuring direction, each multipart sealing element comprising a sealing profile shaped to seal against the follower and an elastic supporting element having a length dimension extending along the measuring direction and shaped to bias the respective sealing profile into sealing engagement with the follower;

the sealing profiles positioned to abut and seal against one another across the slit; and

said follower operating to indent the elastic supporting elements such that the elastic supporting elements are indented maximally in a region aligned with the follower, which region moves along the length of the supporting elements as the follower moves along the measuring direction.

2. The invention of claim 1 wherein each of the supporting elements comprises a respective flexible tube.

3. The invention of claim 1 wherein each of the supporting elements comprises a respective cylindrically symmetric element.

4. The invention of claim 1 wherein each of the sealing profiles comprises a respective tube.

5. The invention of claim 1 wherein the sealing profiles are disposed between the supporting elements.

6. The invention of claim 1 wherein each of the sealing profiles encloses the respective supporting element on several sides.

7. The invention of claim 4 wherein the tubes are disposed between the supporting elements.

8. The invention of claim 4 wherein each of the supporting elements extends around the respective tube by an amount greater than 180°

and less than 360°

.

9. The invention of claim 1 wherein the sealing profiles are formed of a first material adapted to seal the housing and to allow smooth sliding motion of the follower, and wherein the supporting elements are formed of a second material, different from the first material, adapted to bias the sealing profiles into sealing engagement.

10. In an encapsulated measuring system for measuring the position of first and second objects movable relative to each other, of the type comprising a housing, adapted to be connected to the first object, which defines a slit extending along a measuring direction, a scanning unit disposed in the housing, and a follower, adapted to be connected to the second object and coupled to the scanning unit to move along the measuring direction and to extend through the slit, said follower having a convex shape in the measuring direction, the improvement comprising:

a pair of sealing strips, each secured to the housing on a respective side of the slit such that the sealing strips seal against one another across the slit and the follower passes between the sealing strips, said sealing strips formed of a first material adapted to seal the housing and to allow smooth sliding motion of the follower; and

a pair of flexible, tubular supporting elements, each secured to the housing on a respective side of the slit and in contact with the respective sealing strip to bias the sealing strips into sealing engagement and into sealing engagement with the follower, said supporting elements formed of a second material, different from the first material, adapted to bias the sealing strips together, and each of said supporting elements defining a length dimension extending along the measuring direction;

said follower operating to indent the supporting elements such that the supporting elements are indented maximally in a region aligned with the follower, which region moves along the length of the supporting elements as the follower moves along the measuring direction.