Gate valve apparatus and method

• US 4,572,298 A
• Filed: 11/04/1983
• Issued: 02/25/1986
• Est. Priority Date: 11/05/1982
• Status: Expired due to Term

• Current Assignee: Hydril Company L P (General Electric Company)
• Original Assignee: Hydril Company L P (General Electric Company)
• Inventors: Weston, Harry
• Primary Examiner(s): Leppink, James A.
• Assistant Examiner(s): Dang, Hoang C.
• Application Number:
  US06/549,255
• Time in Patent Office: 844 Days
• Field of Search: 166/75 R, 166/76, 166/77, 166/80, 166/86, 166/95, 166/97, 166/316, 166/320, 166/330, 166/332, 166/373, 166/379, 166/378, 166/381, 166/386, 166/374, 251/327, 251/329, 137/625.48
• US Class Current: 166/379
• CPC Class Codes: E21B 2200/04 Ball valves
• CPC Class Codes: E21B 29/04 Cutting of wire lines or the like E21B29/02 takes precedence
• CPC Class Codes: E21B 29/08 Cutting or deforming pipes to control fluid flow
• CPC Class Codes: E21B 34/04 in underwater well heads
• CPC Class Codes: F16K 11/0655 with flat slides
• CPC Class Codes: F16K 11/0873 the plug being only rotatable around one spindle
• CPC Class Codes: F16K 3/0209 the valve having a particular passage, e.g. provided with a filter, throttle or safety device
• CPC Class Codes: F16K 31/122 the fluid acting on a piston F16K31/143, F16K31/163, F16K31/363, F16K31/383 take precedence
• CPC Class Codes: F16K 31/535 for rotating valves F16K31/54 takes precedence
• CPC Class Codes: F16K 31/54 with pinion and rack
• CPC Class Codes: F16K 5/0605 with particular plug arrangements, e.g. particular shape or built-in means
• CPC Class Codes: Y10T 137/6035 Rotary ball valve
• CPC Class Codes: Y10T 137/6154 With disassembly tool engaging feature
• CPC Class Codes: Y10T 137/86871 Plug
• CPC Class Codes: Y10T 137/86879 Reciprocating valve unit

Abstract

Safety equipment for land or marine well completions is disclosed. In one embodiment of the invention a gate valve is provided in which the gate has a removable insert so that in one position of the valve, the insert can be removed (or inserted) via an upper vertical passage of the valve to provide full-bore access via an attached blowout preventer stack to the well head below.

In another embodiment of the invention a gate valve is provided having at least two vertical passages through the gate. The first is large enough to provide full-bore access via an upper passage in the housing of the valve. The second is of a smaller diameter to provide vertical communication with tubing disposed in a lower vertical passage and in an upper vertical passage.

Either of the above embodiments may be used in a lateral production tree where the gate is provided with an "L" or "T" shaped passage in another lateral portion of the gate and lateral outlets are provided in the valve housing.

This abstract of the disclosure is neither intended to define the scope of the invention, which is measured by the claims, nor is it intended to limit the invention in any way.

Claims

1. A valve comprising,

a housing having a vertical housing passage and a lateral housing passage, said vertical and lateral passages intersecting each other,

a laterally movable gate disposed in said lateral passage, said gate having

a first lateral portion with a first gate vertical passage having a diameter substantially the same as or less than the vertical housing passage,

a second lateral portion having no vertical passage therethrough, and

a third lateral portion with a second gate vertical passage having a diameter smaller than said first gate vertical passage,

means for laterally moving said gate in said lateral housing passage between at least two positions:

the first position where said gate is in a lateral position such that said first gate vertical passage is aligned with said vertical housing passage and full diameter access through the vertical housing and the first gate vertical passage is provided, and

the second position where said gate is in a second lateral position such that said second lateral portion of said gate is aligned with said vertical housing passage and the vertical flow path through the vertical housing passage is closed.

2. The valve of claim 1 further comprising,

means for disposing upper and lower conduits in said vertical housing passage, the upper conduit having its lower end open to the intersecting lateral passage, the lower conduit having its upper end open to the intersecting lateral passage and is insertable through said first gate vertical passage when said first gate is in said first position, and

the lateral moving means is adapted to move said gate among said two positions and a third position:

the third position where said gate is in a lateral position such that said second gate vertical passage is aligned with the open lower end of the upper conduit and the open upper end of the lower conduit.

3. The valve of claim 2 further comprising,

at least one lateral outlet in said housing, said lateral outlet being substantially perpendicular to said vertical housing passage and to said lateral housing passage and being open to the intersection of the lateral housing passage and the vertical housing passage, and

the gate further having,

a fourth lateral portion with a gate "L" shaped passage therein, the "L" shaped passage having an opening in the bottom of the gate and an opening in a side portion of the gate,

the lateral moving means being adapted to move said gate among said three positions and a fourth position:

the fourth position where said gate is in a lateral position such that said gate "L" shaped passage has its opening in the bottom of the gate aligned with the upper end of the lower conduit in the vertical housing passage and its opening in the side portion of the gate aligned with the lateral outlet in said housing.

4. The valve of claim 2 further comprising,

two lateral outlets in said housing, said lateral outlets being substantially perpendicular to said vertical housing passage and to said lateral housing passage, each of the outlets being open to the intersection of the lateral housing passage and the vertical housing passage, and

the gate further having,

a fourth lateral portion with a gate "T" shaped passage therein, the "T" shaped passage having a base passage with an opening in the bottom of the gate and a head passage intersecting the base passage and having openings in the sides of the gate, and

the lateral moving means is adapted to move said gate among said three positions and a fourth position:

the fourth position where said gate is in a lateral position such that said gate "T" shaped passage has its opening in the bottom of the gate aligned with the upper end of the lower conduit in the vertical housing passage and its openings in the sides of the gate aligned with the respective lateral outlets in the housing.

5. The valve of claim 4 further comprising

two diverter valves, one each attached to each of the two lateral outlets.

6. The valve of claim 3 further comprising,

a diverter valve attached to the lateral outlet.

7. A valve comprising,

a housing having coaxial upper and lower vertical housing passages and a lateral housing passage, said lateral passage intersecting said upper vertical housing passage and said lower housing passage and at least one lateral outlet in said housing, said lateral outlet being substantially perpendicular to said vertical housing passage and to said lateral housing passage and being open to the intersection of the lateral housing passage and the vertical housing passage,

a laterally movable gate disposed in said lateral passage, said gate having

a first lateral portion with a gate vertical passage having a diameter substantially the same as or less than the upper vertical housing passage,

a second lateral portion with a second gate vertical passage having a diameter smaller than said first gate vertical passage, and

a third lateral portion with a gate "L" shaped passage therein, the "L" shaped passage having an opening in the bottom of the gate and an opening in a side portion of the gate, whereby,

when said gate is in a lateral position where said first gate vertical passage is aligned with said vertical housing passage, full diameter access through the vertical housing passage and the first vertical passage is provided.

8. The valve of claim 7 further comprising

means for disposing upper and lower conduits in said vertical housing passage, the upper conduit having its lower end open to the intersecting lateral passage, the lower conduit having its upper end open to the intersecting lateral passage,

means for laterally moving said gate in said lateral housing passage between at least two positions:

the first position where said gate is in a lateral position such that said first gate vertical passage is aligned with said vertical housing passage and full diameter access through the vertical housing and the first gate vertical passage is provided, and

the second position where said gate is in a lateral position such that said second gate vertical passage is aligned with the open lower end of the upper conduit and the open upper end of the lower conduit.

9. The valve of claim 8 wherein

the lateral moving means is adapted to move the gate among the two positions and a third position:

the third position where said gate is in a lateral position such that said gate "L" shaped passage has its opening in the bottom of the gate aligned with the upper end of the lower conduit in the vertical housing passage and its opening in the side portion of the gate aligned with the lateral outlet in said housing.

10. The valve of claim 9 further comprising,

a diverter valve attached to the lateral outlet.

11. The valve of claim 9 further comprising,

means for cutting a wireline extending through said upper and lower vertical passages and through said second gate vertical passage upon moving said gate from said second position to said third position.

12. A valve comprising,

a housing having coaxial upper and lower vertical housing passages and a lateral housing passage, said lateral passage intersecting said upper vertical housing passage and said lower housing passage,

a laterally movable gate disposed in said lateral passage, said gate having

a first lateral portion with a first gate vertical insert cavity, the insert cavity having an inner diameter substantially the same as or less than that of the upper vertical housing passage, and

a removable inner part disposed in said insert cavity having an outer diameter substantially the same as that of the insert cavity and having a vertical passage, whereby

when said vertical insert cavity of said first lateral portion of said gate is aligned with said upper and lower vertical housing passages, said removable inner part may be removed from or inserted in the insert cavity via the upper vertical housing passage.

13. The valve of claim 12 further comprising

means for laterally moving said gate in said lateral housing passage between at least two positions:

the first position where the vertical passage of the inner part is aligned with the upper and lower vertical housing passages allowing fluid communication between the upper and lower passages of the housing, and

the second position where a second lateral portion of the gate having no passage extending through it covers the lower housing passage, thereby closing the flow path from the lower passage to the upper passage of the housing.

14. The valve of claim 13 further comprising

means for disposing upper and lower conduits, respectively, in said upper and lower vertical housing passages, the upper conduit having its lower end open to the intersecting lateral passage, the lower conduit having its upper end open to the intersecting lateral passage, and

whereby in the first position, said inner part is aligned with the upper and lower conduits allowing fluid communication therebetween.

15. The valve of claim 18 further comprising

at least one lateral outlet in said housing, said lateral outlet being substantially perpendicular to said vertical housing passage and to said lateral housing passage and being open to the intersection of the lateral housing passage and the vertical housing passage, and

the gate further having,

a third lateral portion with a gate "L" shaped passage therein, the "L" shaped passage having an opening in the bottom of the gate and an opening in a side portion of the gate,

the lateral moving means being adapted to move said gate among said first and second positions and a third position:

the third position where said gate is in a lateral position such that said "L" shaped passage has its opening in the bottom of the gate aligned with the upper end of the lower conduit in the vertical housing passage and its opening in the side of the gate aligned with the lateral outlet in said housing.

16. The valve of claim 15 further comprising,

a diverter valve attached to the lateral outlet.

17. The valve of claim 14 further comprising

two lateral outlets in said housing, said lateral outlets being substantially perpendicular to said vertical housing passage and to said lateral housing passage, each of the outlets being open to the intersection of the lateral housing passage and the vertical housing passage,

the gate further having

a third lateral portion with a gate "T" shaped passage therein, the "T" shaped passage having a base passage with an opening in the bottom of the gate and a head passage intersecting the base passage and having openings in the sides of the gate,

the lateral moving means being adapted to move said gate among said first and second positions and a third position:

the third position where said gate is in a lateral position such that said gate "T" shaped passage has its opening in the bottom of the gate aligned with the upper end of the lower conduit in the vertical housing passage and its openings in the sides of the gate aligned with the respective lateral outlets in the housing.

18. The valve of claim 17 further comprising

two diverter valves, one each attached to each of the two lateral outlets.

19. A valve comprising,

a housing having coaxial upper and lower vertical housing passages and a lateral housing passage, said lateral passage intersecting said upper vertical housing passage and said lower housing passage and at least one lateral outlet in said housing, said lateral outlet being substantially perpendicular to said vertical housing passage and to said lateral housing passage and being open to the intersection of the lateral housing passage and the vertical housing passage,

a laterally movable gate disposed in said lateral passage, said gate having

a first lateral portion with a first gate vertical insert cavity, the insert cavity having an inner diameter substantially the same as or less than that of the upper vertical housing passage, and

a removable inner part disposed in said insert cavity and having a vertical passage, whereby

when said vertical insert cavity of said first lateral portion of said gate is aligned with said upper and lower vertical housing passages, said removable inner part may be removed from or inserted in the insert cavity via the upper vertical housing passage,

a second lateral portion with a gate "L" shaped passage therein, the "L" shaped passage having an opening in the bottom of the gate and an opening in a side portion of the gate, and

means for laterally moving said gate in said lateral housing passage between at least two positions:

the first position where the vertical passage of the inner part is aligned with the upper and lower vertical housing passages allowing fluid communication between the upper and lower passages of the housing, and

the second position where said gate is in a lateral position such that said "L" shaped passage has its opening in the bottom of the gate aligned with the upper end of the lower conduit in the vertical housing passage and its opening in the side of the gate aligned with the lateral outlet in said housing.

20. The valve of claim 19 further comprising,

means for disposing upper and lower conduits, respectively, in said upper and lower vertical housing passages, the upper conduit having its lower end open to the intersecting lateral passage, the lower conduit having its upper end open to the intersecting lateral passage, and

whereby in the first position, said inner part is aligned with the upper and lower conduits allowing fluid communication therebetween.

21. The valve of claim 20 further comprising

a diverter valve attached to the later outlet.

22. A production tree for connection to the tubing head of an oil and gas well comprising,

a master valve adapted for connection to said tubing head of the well having,

a housing having coaxial upper and lower vertical housing passages and a lateral housing passage, said lateral passage intersecting said upper vertical housing passage and said lower housing passage, and at least one lateral outlet in said housing, said lateral outlet being being substantially perpendicular to said vertical housing passage and to said lateral housing passage and being open to the intersection of the lateral housing passage and to the vertical housing passage, and

a laterally movable gate disposed in said lateral passage, said gate having

a first lateral portion with a first gate vertical insert cavity, the insert cavity having an inner diameter substantially the same as or less than that of the upper vertical housing passage,

a removable inner part removably disposed via said upper vertical housing passage in said insert cavity having an outer diameter substantially the same as that of the insert cavity and having a vertical passage,

means for coupling production tubing landed in said tubing head with the lower housing passage of said master valve,

a second lateral portion in said gate with a gate "L" shaped passage therein, the "L" shaped passage having an opening in the bottom of the gate and an opening in a side portion of the gate,

means for laterally moving said gate in said lateral housing passage, and

control valve means attached to said lateral outlet for controlling fluid flow in the production tubing in the well.

23. The control valve of claim 22 further comprising

a third lateral portion of the gate having no passage through it.

24. The production tree of claim 22 further comprising,

means for attaching a blowout preventer to the upper passage of said housing, whereby control over the well is maintained during removal of said inner part of said gate during workover operations.

25. The production tree of claim 22 further comprising,

means for capping said upper passage of said housing.

26. A production tree for connection to the tubing head of an oil and gas well comprising

a master valve adapted for connection to said tubing head of the well having,

a housing having coaxial upper and lower vertical housing passage and a lateral housing passage, said lateral passage intersecting said upper vertical housing passage and said lower housing passage, and two lateral outlets in said housing, said lateral outlets being substantially perpendicular to said vertical housing passage and to said lateral housing passage and being open to the intersection of the lateral housing passage and to the vertical housing passage, and

a laterally movable gate disposed in said lateral passage, said gate having

a first lateral portion with a first gate vertical insert cavity, the insert cavity having an inner diameter substantially the same as or less than that of the upper vertical housing passage,

a removable inner part removably disposed via said upper vertical housing passage in said insert cavity having an outer diameter substantially the same as that of the insert cavity and having a vertical passage,

means for coupling production tubing landed in said tubing head with the lower housing passage of said master valve, and

a second lateral portion in said gate with a gate "T" shaped passage therein, the "T" shaped passage having a base passage with an opening in the bottom of the gate and a head passage intersecting the base passage and having openings in the sides of the gate,

means for laterally moving said gate in said lateral housing passage, and

control valve means attached to said lateral outlets for controlling fluid flow in the production tubing in the well.

27. The production tree of claim 26 further comprising

a third lateral portion of the gate having no passage extending through it.

28. The production tree of claim 26 further comprising,

means for attaching a blowout preventer to the upper passage of said housing, whereby control over the well is maintained during removal of said inner part of said gate during workover operations.

29. The production tree of claim 26 further comprising,

means for capping said upper passage of said housing.

30. The safety valve of claim 26 further comprising

two diverter valves, one each attached to each of the two lateral outlets.

31. A safety valve adapted for controlling a well and adapted for placement between a tubing head and a blowout preventer stack or a production tree comprising,

a housing having coaxial upper and lower vertical housing passages and a lateral housing passage, said lateral passage intersecting said upper vertical housing passage and said lower housing passage, and

two lateral outlets in said housing, said lateral outlets being substantially perpendicular to said vertical housing passage and to said lateral housing passage, each of the outlets being open to the intersection of the lateral housing passage and the vertical housing passage,

means for disposing upper and lower conduits, respectively, in said upper and lower vertical housing passages, the upper conduit having its lower end open to the intersecting lateral passage, the lower conduit having its upper end open to the intersecting lateral passage,

a laterally movable gate disposed in said lateral housing, said gate having

a first lateral portion with a first gate vertical insert cavity, the insert cavity having an inner diameter substantially the same as or less than that of the upper vertical housing passage,

a removable inner part removably disposed via said upper vertical housing passage in said insert cavity having an outer diameter substantially the same as that of the insert cavity and having a vertical passage,

a second lateral portion of the gate having no passage extending through it, and

a third lateral portion of the gate with a gate "T" shaped passage therein, the "T" shaped passage having a base passage with an opening in the bottom of the gate and a head passage intersecting the base passage and having openings in the sides of the gate,

means for laterally moving said gate in said lateral housing passage among at least three positions:

the first position where the vertical passage of the inner part is aligned with the upper and lower vertical housing passages allowing fluid communication between upper and lower passages of the housing, and

the second position where a second lateral portion of the gate having no passage extending through it covers the lower housing passage thereby closing the flow path from the lower passage to the upper passage of the housing, and

the third position where said gate is in a lateral position such that said gate "T" shaped passage has its opening in the bottom of the gate aligned with the upper end of the lower conduit in the vertical housing passage and its openings in the sides of the gate aligned with the respective lateral outlets in the housing.

32. In a well having a wellhead to which is attached a safety valve housing having an upper passage and a lower passage, the lower passage communicating with the wellhead, and each of the upper and lower passages being open to a lateral passage in the housing, a laterally movable gate disposed in said lateral passage, the gate having a first lateral portion with a first gate vertical insert cavity, the insert cavity having an inner diameter substantially the same as or less than that of the upper vertical housing passage and a removable inner part disposed in said insert cavity having an outer diameter substantially the same as that of the insert cavity and having a vertical passage therethrough, the housing having a blowout preventer removably attached to the upper part of the housing with vertical flow path of the blowout preventer communicating with the upper passage of the safety valve, the diameter of the vertical flow path of the blowout preventer being substantially the same as or greater than that of the upper passage of the safety valve, the inner diameter of the insert cavity and the lower passage,

a method for controlling the well during installation of production tubing and a Christmas tree comprising the steps of,

setting tubing in the well through the blowout preventer and the upper passage, the insert cavity of the first lateral portion of the gate, and the lower passage of the safety valve housing,

installing an inner part of the gate within the vertical insert cavity of the first lateral portion of the gate, the inner part having an outer diameter substantially the same as that of the insert cavity of the first lateral portion,

laterally moving said gate within the safety valve housing until flow form the tubing is prevented access to the upper passage of the housing,

removing the blowout preventer from the upper part of the housing,

installing a Christmas tree to the upper part of the housing, and

laterally moving the gate within the safety valve to a position where the vertical passage of the inner part completes the vertical flow path from the tubing in the wellhead below to the Christmas tree above the safety valve housing.

33. The method of claim 32 wherein the gate further includes a portion with a "T" shaped passage therein, the "T" shaped passage having a base passage with an opening in the bottom of the gate and a head passage intersecting the base passage and having openings in the sides of the gate, the housing having two lateral outlets being substantially perpendicular to said upper and lower passage and to said lateral housing passage, each of the outlets being open to the intersection of the lateral housing passage and said upper and lower passages, and a diverter valve being attached to each of said outlets, and

the step of moving the gate within the housing to prevent flow from the tubing to the upper passage of the housing comprises

moving the gate laterally within the housing until the head passage of the "T" is aligned with said lateral outlets of the housing and said base passage of the "T" is aligned with said tubing, and a portion of the upper surface of the gate having no passage extending through it covers the flow path to the upper passage of the housing.

34. The method of claim 33 further comprising the step of opening one or both of the diverter valves whereby fluid in said tubing may be diverted away from said wellhead.

35. The method of claim 33 further comprising the step of

laterally moving said gate until the lateral portion of the gate having no passage extending through it covers the lower passage of the housing such that flow from the tubing is prevented access to the upper passage of the housing.

36. In a well having a wellhead to which is attached a safety valve housing having an upper passage and a lower passage, the lower passage communicating with the wellhead, and each of the upper and lower passages being open to a lateral passage in the housing, a laterally movable gate disposed in said lateral passage, the gate having a first lateral portion with a first gate vertical passage having a diameter substantially the same as or less than the vertical housing passage, and a second lateral portion with a second gate vertical passage having a diameter smaller than said first gate vertical passage, the housing having a blowout preventer removably attached to the upper part of the housing with the vertical flow path of the blowout preventer communicating with the upper passage of the safety valve, the diameter of the vertical flow path of the blowout preventer being substantially the same as or greater than that of the upper passage of the safety valve, the inner diameter of the insert cavity and the lower passage,

a method for controlling the well during installation of production tubing and a Christmas tree comprising the steps of,

setting tubing in the well through the blowout preventer and the upper passage, the first gate vertical passage and the lower passage of the safety valve,

laterally moving said gate within the safety valve housing until flow from the tubing is prevented access to the upper passage of the housing,

removing the blowout preventer from the upper part of the housing,

installing a Christmas tree to the upper part of the housing, and

laterally moving the gate within the safety valve to a position where the second gate vertical passage completes the vertical flow path from the tubing in the wellhead below to the Christmas tree above the safety valve housing.

37. A gate adapted for use in a valve housing with a vertical housing passage and a lateral housing passage, said vertical and lateral passages intersecting each other, and at least one lateral outlet in said housing, said lateral outlet being substantially perpendicular to said vertical housing passage and to said lateral housing passage and being open to the intersection of the lateral housing passage and the vertical housing passage, the gate comprising,

a first lateral portion with a first gate vertical passage having a diameter substantially the same as the vertical housing passage,

a second lateral portion with a second vertical passage having a diameter smaller than said first gate vertical passage, and

a third lateral portion with a gate "L" shaped passage therein, the "L" shaped passage having an opening in the bottom of the gate and an opening in a side portion of the gate,

said gate being adapted to be laterally movable within said lateral housing passage.

38. The gate of claim 37 further comprising

a fourth lateral portion having no vertical passage therethrough.

39. A gate adapted for use in a valve housing with a vertical housing passage and a lateral housing passage, said vertical and lateral passages intersecting each other, and two lateral outlets in said housing, said lateral outlets being substantially perpendicular to said vertical housing passage and to said lateral housing passage, each of the outlets being open to the intersection of the lateral housing passage and the vertical housing passage, the gate comprising,

a first lateral portion with a first gate vertical passage having a diameter substantially the same as the vertical housing passage,

a second lateral portion with a second vertical passage having a diameter smaller than said first gate vertical passage, and

a third lateral portion with a gate "T" shaped passage therein, the "T" shaped passage having a base passage within an opening in the bottom of the gate and a head passage intersecting the base passage and having openings in the sides of the gate,

said gate being adapted to be laterally movable within said lateral housing passage.

40. The gate of claim 39 further comprising

a fourth lateral portion having no vertical passage therethrough.

41. A gate adapted for use in a valve housing, the housing having coaxial upper and lower vertical housing passages and lateral housing passage, said lateral passage intersecting said upper and lower housing passages, and at least one lateral outlet in said housing, said later outlet being substantially perpendicular to said vertical housing passage and to said lateral housing passage and being open to the intersection of the lateral housing passage and the vertical housing passage, the gate comprising,

a first lateral portion with a first vertical insert cavity, the insert cavity having an inner diameter substantially the same as or less than that of the upper vertical housing passage, and

a removable inner part removably disposed via said upper vertical housing passage in said insert cavity having an outer diameter substantially the same as that of the insert cavity and having a vertical passage therein, and

a second lateral portion with a gate "L" shaped passage therein, the "L" shaped passage having an opening in the bottom of the gate and an opening in a side portion of the gate,

said gate being adapted to be laterally movable within said lateral housing passage.

42. The gate of claim 41 further comprising

a third lateral portion having no vertical passage therethrough.

43. A gate adapted for use in a valve housing, the housing having coaxial upper and lower vertical housing passages and a lateral housing passage, said lateral passage intersecting said upper and lower housing passages, and two lateral outlets in said housing, said lateral housing passages being substantially perpendicular to said vertical housing passage and to said lateral housing passage and being open to the intersection of the lateral housing passage and the vertical housing passage, the gate comprising,

a first lateral portion with a first vertical insert cavity, the insert cavity having an inner diameter substantially the same as or less than that of the upper vertical housing passage, and

a removable inner part removably disposed via said upper vertical housing passage in said insert cavity having an outer diameter substantially the same as that of the insert cavity and having a vertical passage therein, and

a second lateral portion with a gate "T" shaped passage therein, the "T" shaped passage having a base passage with an opening in the bottom of the gate and a head passage intersecting the base passage and having openings in the sides of the gate,

said gate being adapted to be laterally movable within said lateral housing passage.

44. The gate of claim 43 further comprising

a third lateral portion having no vertical passage therethrough.