Automatic adjustment tube for carpet stretcher tool

Abstract

A carpet stretcher device has an automatic adjusting tube that changes length with telescoping motion of an inside tube and an outside tube. A housing is mounted on the outside tube, and at least one lever is connected to the housing. A hand lever controls the motion of a spring-loaded rotating arm with a locking button positioned within the housing to insert and remove the locking button from holes in the tubes. When lifted away from the housing, the hand lever releases the rotating arms, which rotate to remove the locking button from holes in the tubes and thereby allow the tubes to telescope. The carpet stretcher may also have a floor lever that retracts when the device contacts a floor surface and extends when the device is lifted off a floor surface. When extended, the floor lever also releases the rotating arms, thereby allowing the tubes to telescope.

Claims

1. An automatic adjusting tube for a carpet stretcher, comprising: an outside tube with a hole; an inside tube that telescopes with the outside tube and has a plurality of holes with least one hole that aligns with the hole of the outside tube; a housing on the outside tube; a rotating arm that pivots on a first pivot with a locking button within the housing, wherein the locking button passes through the hole of the outside tube and into a one of the plurality of holes of the inside tube that is aligned with the hole of the outside tube; and a lever that pivots on a second pivot different than the first pivot to rotate the rotating arm to move the locking button in a direction outward of the one of the plurality of holes of the inside tube that is aligned with the hole of the outside tube.

2. The automatic adjusting tube of claim 1, wherein extending the lever away from the housing rotates the rotating arm.

3. The automatic adjusting tube of claim 1, wherein when the automatic adjusting tube is attached to a power head of the carpet stretcher on a floor surface, the lever is connected to a top portion of the housing that faces away from the floor surface when the carpet stretcher is in use.

4. The automatic adjusting tube of claim 1, further comprising: a spring that urges the rotating arm to rotate, wherein when the lever is retracted towards the housing, the spring rotates the rotating arm to insert the locking button within the one of the plurality of holes in the inside tube that is aligned with the hole of the outside tube.

5. The automatic adjusting tube of claim 4, wherein the spring urges the rotating arm to rotate to an oblique angle in relation to the long axis of the outside tube.

6. The automatic adjusting tube of claim 1, wherein moving the automatic adjustment tube off a floor surface moves the lever, which causes the lever to rotate the rotating arm.

7. The automatic adjusting tube of claim 6, further including a lock pin to prevent the lever from moving.

8. The automatic adjusting tube of claim 1, further comprising a spring that urges the lever to extend from the housing, wherein moving the automatic adjustment tube off a floor surface extends the lever.

9. The automatic adjusting tube of claim 1, wherein the rotating arm includes a bend forming a surface the lever contacts to rotate the rotating arm.

10. The automatic adjusting tube of claim 9, wherein the housing includes a contour forming a fulcrum on which the bend of the rotating arm rotates.

11. The automatic adjusting tube of claim 1, further including a safety lock hole in the outside tube, a safety lock hole in the inside tube, and a spring clip with a locking button, wherein the safety lock hole of the outside tube and the safety lock hole of the inside tube are formed on a different plane than the hole of the outside tube and the plurality of holes of the inside tube, and wherein the locking button of the spring clip passes through the safety lock hole in the inside tube and the safety lock hole in the outside tube to lock the inside tube with the outside tube after the locking button of the rotating arm passes beyond the plurality of holes in the inside tube.

12. An automatic adjusting tube for a carpet stretcher, comprising: an outside tube with a hole; an inside tube that telescopes with the outside tube and has a plurality of holes with at least one hole that aligns with the hole of the outside tube; a housing on the outside tube; a rotating arm in the housing, the rotating arm including a locking button that passes through the hole of the outside tube and into a one of the plurality of holes of the inside tube that is aligned with the hole of the outside tube; and a lever attached to the housing, wherein lifting the lever rotates the rotating arm to move the locking button in a direction outward of the one of the plurality of holes in the inside tube that is aligned with the hole of the outside tube.

13. The automatic adjusting tube of claim 12, further comprising: a spring that urges the rotating arm to rotate, wherein lowering the lever from the lifted position releases the rotating arm to rotate to insert the locking button within the one of the plurality of holes in the inside tube that is aligned with the hole of the outside tube.

14. The automatic adjusting tube of claim 13, wherein the spring urges the rotating arm to rotate to an oblique angle in relation to the long axis of the outside tube.

15. The automatic adjusting tube of claim 12, wherein the rotating arm includes a bend forming a surface the lever contacts to rotate the rotating arm.

16. The automatic adjusting tube of claim 15, wherein the housing includes a contour forming a fulcrum on which the bend of the rotating arm rotates.

17. An automatic adjusting tube for a carpet stretcher, comprising: an outside tube with a hole; an inside tube that telescopes with the outside tube and has a plurality of holes with at least one hole that aligns with the hole of the outside tube; a housing on the outside tube; a rotating arm in the housing, the rotating arm including a locking button that passes through the hole of the outside tube and into a one of the plurality of holes of the inside tube that is aligned with the hole of the outside tube; and a lever attached to the housing that extends toward a floor surface, wherein when the automatic adjusting tube is placed on a floor surface, moving the automatic adjustment tube off a floor surface extends the lever towards the floor surface and rotates the rotating arm to move the locking button in a direction outward of the one of the plurality of holes of the inside tube that is aligned with the hole of the outside tube.

18. The automatic adjusting tube of claim 17, further including a spring that urges the lever to extend towards the floor surface.

19. The automatic adjusting tube of claim 17, further comprising: a lock pin to prevent the lever from extending.

20. The automatic adjusting tube of claim 17, further including: a spring that urges the rotating arm to rotate, wherein retracting the lever from the extended position releases the rotating arm to rotate to insert the locking button within the hole in the inside tube.

21. The automatic adjusting tube of claim 20, wherein the spring urges the rotating arm to rotate to an oblique angle in relation to the long axis of the outside tube.

22. The automatic adjusting tube of claim 17, wherein the rotating arm includes a bend forming a surface the lever contacts to rotate the rotating arm.

23. The automatic adjusting tube of claim 22, wherein the housing includes a contour forming a fulcrum on which the bend of the rotating arm rotates.

24. An automatic adjusting tube for a carpet stretcher, comprising: an outside tube with a hole; an inside tube that telescopes with the outside tube and has a plurality of holes with at least one hole that aligns with the hole of the outside tube; a rotating arm that pivots on a first pivot with a locking button that passes through the hole of the outside tube and into a one of the plurality of holes of the inside tube that is aligned with the hole of the outside tube; and a lever that pivots on a second pivot different from the first pivot to rotate the rotating arm to move the locking button in a direction outward of the hole of the inside tube that is aligned with the hole of the outside tube.

25. An automatic adjusting tube for a carpet stretcher, comprising: an outside tube with a hole; an inside tube that telescopes with the outside tube and has a plurality of holes with at least one hole that aligns with the hole of the outside tube; a housing on the outside tube; a rotating arm with a locking button within the housing, wherein the locking button passes through the hole of the outside tube and into a one of the plurality of holes of the inside tube that is aligned with the hole of the outside tube; a hand lever attached to the housing, wherein lifting the hand lever rotates the rotating arm to move the locking button in a direction outward of the one of the plurality of holes in the inside tube that is aligned with the hole of the outside tube; and a floor lever attached to the housing that extends toward a floor surface, wherein when the automatic adjusting tube is placed on the floor surface, moving the automatic adjustment tube off the floor surface extends the floor lever and rotates the rotating arm to move the locking button in a direction outward of the one of the plurality of holes of the inside tube that is aligned with the hole of the outside tube.

26. The automatic adjusting tube of claim 25, further comprising: a spring that urges the rotating arm to rotate to insert the locking button within the one of the plurality of holes in the inside tube that is aligned with the hole of the outside tube.

27. The automatic adjusting tube of claim 26, wherein the spring urges the rotating arm to rotate to an oblique angle in relation to the long axis of the outside tube.

28. The automatic adjusting tube of claim 25, wherein the rotating arm includes a bend forming a surface the lever contacts to rotate the rotating arm.

29. The automatic adjusting tube of claim 28, wherein the housing includes a contour forming a fulcrum on which the bend of the rotating arm rotates.

30. The automatic adjusting tube of claim 25, further including a spring that urges the floor lever to extend towards the floor surface.

31. The automatic adjusting tube of claim 25, further comprising: a lock pin to prevent the floor lever from extending.

32. An automatic adjusting tube for a carpet stretcher, comprising: an outside tube with a hole; an inside tube that telescopes with the outside tube and has a plurality of holes with at least one of the plurality of holes that aligns with the hole of the outside tube; a locking button that passes through the hole of the outside tube and into one of the plurality of holes of the inside tube that is aligned with the hole of the outside tube; and a lever that pivots away from the outside tube to move the locking button in a direction outward of the one of the plurality of holes of the inside tube that is aligned with the hole of the outside tube.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows an assembled prior art carpet stretcher in a room.

(2) FIG. 2 shows an exploded view of an extension tube of a prior art carpet stretcher.

(3) FIGS. 3 and 4 show the extension and retraction of prior art carpet stretchers for example rooms including walls that jog in and out.

(4) FIG. 5 is an exploded view of an automatic adjustment tube for a carpet stretcher, in accordance with an embodiment of the invention.

(5) FIG. 6 is an assembled view of an automatic adjustment tube for a carpet stretcher, with a hand lever in a retracted position, in accordance with an embodiment of the invention.

(6) FIG. 7 is a cross sectional view of the automatic adjustment tube of FIG. 6 with the hand lever in the retracted position, along line A-A.

(7) FIG. 8 is an assembled view of automatic adjustment tube for a carpet stretcher, with the hand lever in an extended position, in accordance with an embodiment of the invention.

(8) FIG. 9 is a cross sectional view of the automatic adjustment tube of FIG. 8 with the hand lever in the extended position, along line B-B.

(9) FIG. 10 is an assembled view of an automatic adjustment tube for a carpet stretcher, with a floor lever in a retracted position, in accordance with an embodiment of the invention.

(10) FIG. 11 is a cross sectional view of the automatic adjustment tube of FIG. 10 with the floor lever in the retracted position, along line C-C.

(11) FIG. 12 is an assembled view of the automatic adjustment tube of FIG. 10, with the floor lever in an extended position, in accordance with an embodiment of the invention.

(12) FIG. 13 is a cross sectional view of the automatic adjustment tube of FIG. 12 with the floor lever in the extended position, along line D-D.

(13) FIG. 14 is an assembled view of an automatic adjustment tube for a carpet stretcher, with the hand lever in an extended position, in accordance with an embodiment of the invention.

(14) FIG. 15 is a cross sectional view of an automatic adjustment tube of FIG. 14 with the hand lever in an extended position, along line E-E.

(15) FIG. 16 is an assembled view of an automatic adjustment tube for a carpet stretcher, with the floor lever in an extended position, in accordance with an embodiment of the invention.

(16) FIG. 17 is a cross sectional view on an automatic adjustment tube FIG. 16 with the floor lever in an extended position, along line F-F.

(17) The figures depict various embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the invention described herein.

DETAILED DESCRIPTION

(18) As shown in FIG. 5, automatic adjusting tube 1000 includes outside tube 1020, inside tube 1040, hand lever 1100, housing top 1200, rotating arm 1510 with locking button 1511, rotating arm 1520 with locking button 1521, rotating arm springs 1512, 1522, housing bottom 1300, floor lever 1400, floor lever springs 1702, 1704 that activate floor lever 1400, and lock pin 1600 to lock floor lever 1400 in a retracted position.

(19) Hand lever 1100 pivots on housing top 1200 at its hand lever holes 1102, 1104. Bushings 1106, 1108 are inserted into hand lever holes 1102, 1104, and fasteners 1110, 1112 are passed through bushings 1106, 1108 and fastened into housing top lever holes 1202, 1204. Hand lever arms 1114, 1116 are inserted into hand lever arm slots 1214, 1216 in housing top 1200. Hand lever spring arm 1119 is inserted into spring arm slot 1219 of housing top 1200. Hand lever retracting spring 1121 is inserted into a hand lever spring holding cavity 1221 in housing top 1200. Hand lever retracting spring 1121 contacts the back of hand lever spring arm 1119 to retract it against housing top 1200 when released by the user.

(20) Floor lever 1400 pivots on housing bottom 1300 at its floor lever holes 1402, 1404. Bushings 1406, 1408 are inserted into floor lever holes 1402, 1404. Fasteners 1410, 1412 are passed through bushings 1406, 1408 and fastened into holes 1302, 1304 of housing bottom 1300. Floor lever arms 1414, 1416 insert into floor lever arm slots 1314, 1316 in housing bottom 1300. A locking arm 1419 inserts into a locking arm slot 1319 in housing bottom half 1300. Locking arm 1419 includes a locking arm hole 1421 formed in conjunction with a locking arm radial slot 1423.

(21) Lock pin 1600 along with ball spring 1330 and ball 1331 create a locking mechanism for floor lever 1400 that operates in two positions. Ball spring 1330 and ball 1331 insert within a ball blind hole 1332 in housing bottom 1300. Lock pin 1600 inserts into lock pin hole 1321 of bottom half 1300, with end 1611 entering first (pull ring 1609 not yet installed). Lock pin 1600 has an inner large diameter 1601, inner groove 1602, outer groove 1604, middle small diameter 1605, and outer medium diameter 1607. Lock pin 1600 passes over ball spring 1330 and ball 1331, holding these inside ball blind hole 1332. Lock pin 1600 extends through locking arm hole 1421 in locking arm 1419 when floor lever 1400 is in a retracted position. Inner large diameter 1601 of lock pin 1600 is larger in diameter than lock pin hole 1321 in housing bottom 1300, thus preventing lock pin 1600 from pulling out. Once lock pin 1600 is assembled in this manner, pull ring 1609 is installed on lock pin 1600.

(22) When lock pin 1600 is in an outer position, ball 1331 is pressured upward by ball spring 1330 and enters an inner groove 1602 of lock pin 1600. With lock pin 1600 in this outer position and floor lever 1400 retracted, middle small diameter 1605 of lock pin 1600 aligns with locking arm hole 1421 of locking arm 1419. Middle small diameter 1605 of lock pin 1600 is smaller in dimension than the width of locking arm radial slot 1423. Thus, as floor lever 1400 pivots downward to extend, middle small diameter 1605 of lock pin 1600 will pass within locking arm radial slot 1423, permitting floor lever 1400 to extend.

(23) With floor lever 1400 is retracted, and lock pin 1600 is in an inner position, ball 1331 enters outer groove 1604, and outer medium diameter 1607 of lock pin 1600 aligns with locking arm hole 1421. Outer medium diameter 1607 of lock pin 1600 is larger in dimension than the width of locking arm radial slot 1423. This prevents floor lever 1400 from extending, if desired, for reasons to be explained below.

(24) Floor lever 1400 is urged to extend by floor lever springs 1702, 1704. Floor lever springs 1702, 1704 are inserted into plungers 1706, 1708 which pass through plunger holes 1346, 1348. Plungers 1706, 1708 contact a top surface 1420 of floor lever 1400, producing pressure on floor lever 1400 to extend it.

(25) Outer tube 1020 is positioned in the midsection 1350 of housing bottom 1300 with a boss 1351 extending into a bottom positioning hole 1021 in outer tube 1020. Rotating arms 1510, 1520 are inserted into cavities 1362, 1364 of housing bottom 1300. Rotating arm springs 1512, 1522 are inserted behind rotating arms 1510, 1520. When holes 1022, 1024 in outside tube 1020 are in alignment with adjustment holes 1042, 1044 of inside tube 1040, rotating arm springs 1512, 1522 urge locking buttons 1511, 1521 to extend through holes 1022, 1024 in outer tube 1020 and insert into adjustment holes 1042, 1044 in inner tube 1040.

(26) Housing top 1200 is positioned on top of outer tube 1020 at midsection 1250 with a boss 1251 inserting into a top positioning hole 1025 in outer tube 1020. Fasteners 1260 pass through holes 1261 in housing top 1200 into holes 1360 in housing bottom 1300 to fasten housing top 1200 to housing bottom 1300.

(27) FIG. 6 shows the assembled adjustment tube 1000, with hand lever 1100 retracted, floor lever 1400 retracted, and section A-A taken in a plane that illustrates the position of hand lever arms 1114, 1116 (FIG. 7). In FIG. 7, section A-A shows that with hand lever 1100 retracted, hand lever arms 1114, 1116 also retract, releasing rotating arms 1510, 1520 to rotate, being urged by rotating arm springs 1512, 1522. As rotating arms 1510, 1520 rotate, locking buttons 1511, 1521 extend through holes 1022, 1024 in outside tube 1020 and insert within adjustment holes 1042, 1044 in inside tube 1040. Holes 1022, 1024 in outside tube 1020 and adjustment holes 1042, 1044 in inside tube 1040 are aligned.

(28) FIG. 8 shows the assembled adjustment extension tube 1000, with hand lever 1100 extended, floor lever 1400 retracted, and section B-B taken in a plane that illustrates the position of hand lever arms 1114, 1116 (FIG. 9) and rotating arms 1510, 1520 (FIG. 9). In FIG. 9, section B-B shows that with hand lever 1100 extended, hand lever arms 1114, 1116 also extend, which rotates rotating arms 1510, 1520 to a position where locking buttons 1511, 1521 are removed from adjustment holes 1042, 1044 in inside tube 1040. Holes 1022, 1024 in outside tube 1020 and adjustment holes 1042, 1044 in inside tube 1040 are aligned.

(29) FIG. 10 shows the assembled automatic adjustment tube 1000, with hand lever 1100 retracted, floor lever 1400 retracted, and section C-C taken in a plane that illustrates the position of floor lever arms 1414, 1416 (FIG. 11) and rotating arms 1510, 1520 (FIG. 11). In FIG. 11, section C-C shows that with floor lever 1400 retracted, floor lever arms 1414, 1416 also retract, releasing rotating arms 1510, 1520 to rotate, being urged by rotating arm springs 1512, 1522. As rotating arms 1510, 1520 rotate, locking buttons 1511, 1521 extend through holes 1022, 1024 in outside tube 1020 and into adjustment holes 1042, 1044 in inside tube 1040. Holes 1022, 1024 in outside tube 1020 and adjustment holes 1042, 1044 in inside tube 1040 are aligned.

(30) FIG. 12 shows the assembled automatic adjustment tube 1000, with hand lever 1100 retracted, floor lever 1400 extended, and section D-D taken in a plane that illustrates the position of floor lever arms 1414, 1416 (FIG. 13) and rotating arms 1510, 1520 (FIG. 13). In FIG. 13, section D-D shows that with floor lever 1400 extended, floor lever arms 1414, 1416 also extend, which rotates rotating arms 1510, 1520 to a position where locking buttons 1511, 1521 are removed from adjustment holes 1042, 1044 in inside tube 1040. Holes 1022, 1024 in outside tube 1020 and adjustment holes 1042, 1044 in inside tube 1040 are aligned.

(31) FIG. 7 shows that rotating arm 1510 includes bend 1514, and rotating arm 1520 includes bend 1524. Housing top 1200 includes contours 1224, 1226 and housing bottom 1300 (FIG. 11) includes contours 1324, 1326 (FIG. 11). The contours 1224, 1226 and 1324, 1326 (FIG. 11) correspond in shape and together form fulcrums for rotating arm 1510, 1520 at bends 1514, 1524. Contours 1224, 1226 and 1324, 1326 (FIG. 11) additionally permit button legs 1515, 1525 of rotating arms 1510, 1520 to rotate to an oblique angle in relation to a long axis 1005 of automatic adjustment tube 1000, being urged by rotating arm springs 1512, 1522. This oblique angle combines with the oblong shape of holes 1022, 1024 (FIG. 5) in outside tube 1020 (longer horizontally than circular adjustment holes 1042, 1042 in inside tube 1040FIG. 5) and the rounded ends of locking buttons 1511, 1521 to allow automatic adjustment tube 1000 to always extend automatically. The difference in shape between holes 1022, 1024 (FIG. 5) in outside tube 1020 and adjustment holes 1042, 1044 in inside tube 1040 wedges locking buttons 1511, 1521 out of these holes as they move past each other. The rounded ends of locking buttons 1511, 1521 also force locking buttons 1511, 1521 out of adjustment holes 1042, 1044 in inside tube 1040. As shown in FIG. 6, if a user pushes back on housing 1225 or pushes on outside tube 1020, automatic adjustment tube 1000 will extend automatically in the direction of arrow 1007 (FIG. 7) even when hand lever 1100 (FIG. 6) and floor lever 1400 (FIG. 6) are not extended.

(32) As shown in FIG. 5, automatic adjustment tube 1000 includes a spring clip 1043 comparable to prior art spring clip 43 (FIG. 2). Spring clip 1043 is inserted at a distal end of inside tube 1040 as shown. The buttons of spring clip 1043 insert within end holes 1046, 1048 which are horizontal in orientation and in the same plane as adjustment holes 1042, 1044 of inside tube 1040. Spring clip 1043 is used to lock automatic adjustment tube 1000 with a receiving tube of a carpet stretcher (e.g., the receiving tube 21 shown in FIG. 1).

(33) As shown in FIG. 5, automatic adjustment tube 1000 additionally includes safety spring clip 1045. Inside tube 1040 includes inside tube safety lock holes 1047, 1049, and outside tube 1020 includes outside tube safety lock holes 1026, 1028. Inside tube safety lock holes 1047, 1049 and outside tube safety lock holes 1026, 1028 are both vertically oriented. Safety spring clip 1045 is inserted at the proximal end of inside tube 1040 as shown. The buttons of safety spring clip 1045 are inserted within inside tube safety lock holes 1047, 1049.

(34) The normal range of adjustment for automatic adjustment tube 1000 is the hole pattern 1041 of adjustment holes 1042, 1044 in inside tube 1040. If the locking buttons 1511, 1521 move beyond hole pattern 1041 (forming a plurality of holes) in the direction of inside tube safety lock holes 1047, 1049, the buttons of safety spring clip 1045 will insert within safety holes 1026, 1028 of outside tube 1020, preventing inside tube 1040 from coming apart from outside tube 1020. Hole pattern 1041 of adjustment holes 1042, 1044 are horizontally oriented, whereas inside tube safety lock holes 1047, 1049 and outside tube safety lock holes 1026, 1028 are vertically oriented in a different plane.

(35) As shown in FIG. 5, automatic adjustment tube 1000 includes lock pin 1600. Lock pin 1600 allows the user to prevent floor lever 1400 from automatically extending and unlocking if automatic adjustment tube 1000 is lifted off the floor. This may desirable for example when carpet stretcher is disassembled and automatic adjustment tube 1000 is lifted off the floor to be carried to another room.

(36) Automatic adjustment tube 1000 can be automatically extended or retracted in the direction of tail block end 50 (FIG. 1) end by lifting hand lever 1100 and pushing or pulling on it. Hand lever 1100 forms a large ergonomic handle surface 1125 to grasp and push or pull. With this large handle surface 1125, the user can more easily adjust automatic adjustment tube 1000 simply by reaching back and grasping at large handle surface 1125. Floor lever 1400 permits the power head of the stretcher to be extended or retracted efficiently in conjunction with the normal operating motion of lifting the power head of the carpet stretcher as required each time a new section of carpet is stretched. Floor lever 1400 can be locked in a retracted position if necessary for example for convenient carrying of the automatic adjustment tube 1000 from room to room on the jobsite.

(37) In one embodiment, the hand lever of the automatic adjustment tube extends a reduced distance from the housing, moving the the rounded ends of the locking buttons in a direction outward of the adjustment holes in the inside tube, but not completely removing the locking buttons from the adjustment holes in the inside tube. FIG. 14 shows automatic extension tube 2000 with hand lever 2100 extended a reduced distance from housing 2225 and a section E-E taken in a plane that illustrates locking buttons 2511, 2521 (FIG. 15) having moved in a direction outward of adjustment holes 2042, 2044 (FIG. 15) in inside tube 2040 (FIG. 15), but not completely removed from adjustment holes 2042, 2044 (FIG. 15). In FIG. 15, Section E-E shows that due to the rounded ends on locking buttons 2511, 2521, locking buttons 2511, 2521 need not be completely removed from adjustment holes 2042, 2044 for outside tube 2020 and inside tube 2040 to extend and retract. This is because the rounded ends on locking buttons 2511, 2521 cause locking buttons 2511, 2521 to move out of 2042, 2044 when outside tube 2020 and inside tube 2040 are extended or retracted.

(38) In another embodiment, the floor lever of the automatic adjustment tube extends a reduced distance from the housing, moving the rounded ends of the locking buttons in a direction outward of the adjustment holes in the inside tube, but not completely removing the locking buttons from the adjustment holes in the inside tube. FIG. 16 shows automatic tension tube 3000 with floor lever 3400 extended a reduced distance from housing 3225 and a section F-F taken in a plane that illustrates locking buttons 3511, 3521 (FIG. 17) having moved in a direction outward of adjustment holes 3042, 3044 (FIG. 17) in inside tube 3040 (FIG. 17), but not completely removed from adjustment holes 3042, 3044 (FIG. 17). In FIG. 17, Section F-F shows that due to the rounded ends on locking buttons 3511, 3521, locking buttons 3511, 3521 need not be completely removed from adjustment holes 3042, 3044 for outside tube 3020 and inside tube 3040 to extend and retract. This is because the rounded ends on locking buttons 3511, 3521 cause locking buttons 3511, 3521 to move out of 3042, 3044 when outside tube 3020 and inside tube 3040 are extended or retracted.

(39) The embodiment of FIGS. 8 and 9 and 12 and 13 also show locking buttons 1511, 1521 moving in a direction outward of adjustment holes 1042, 1044. In FIG. 8, hand lever 1100 extends to rotate rotating arms 1510, 1520 (FIG. 9) to move locking buttons 1511, 1521 (FIG. 9) in the same direction outward of adjustment holes 1042, 1044 (FIG. 9). In FIG. 12, floor lever 1400 extends to rotate rotating arms 1510, 1520 (FIG. 13) to move locking buttons 1511, 1521 in the same direction outward of adjustment holes 1042, 1044.

(40) The foregoing description of the embodiments of the invention has been presented for the purpose of illustration; it is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Persons skilled in the relevant art can appreciate that many modifications and variations are possible in light of the above disclosure. Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based hereon. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

(41) The present illustrated embodiments can be characterized in a number of ways. First, the device could be sold as part of a complete carpet stretcher, as shown in FIG. 1, having an improved automatic extension tube illustrated in any of FIG. 5-15 or set out in this detailed description. The device is connectable to prior art carpet stretcher tools as shown in FIG. 1 and could be sold separately as an accessory for prior art carpet stretcher tools. In addition, the device is connectable to prior art extension tubes as shown in FIG. 2 and could be sold as a part of set of tubes. The device could be sold with or without a carrying case. Alternatively, the device could be sold disassembled. The elements would remain the same, but would require assembly by the user prior to use.