The present invention relates generally to a tool for tensioning the biasing member in a counterbalance system for a movable barrier such as a sectional door. More particularly, the present invention relates to a tensioning tool having a counter that displays the number of turns of applied or removed tension in a biasing member of a counterbalance system. Most particularly, the present invention relates to a removable tool that mates with a counterbalance system of a sectional door and has a counting assembly adapted to monitor and display the amount of tension applied to the counterbalance spring.
Sectional garage doors typically include a counterbalance system that compensates for the weight of the garage door to require a substantially uniform force to move the door throughout its travel between a closed position and an open position, such that the door may be opened with ease and closed without slamming the door to the floor. Counterbalancing is commonly accomplished with extension or torsion springs that are coupled to the door, as by cables, during installation. Torsion springs are conventionally tensioned by winding. This operation is often performed manually, as by inserting winding bars into spring perches to effect rotation. As will be appreciated, this operation can be dangerous, and, thus, various devices have been designed to reduce the danger of tensioning the springs.
One known design employs a power tool having a rotatable drive member mounted on a casing carrying a power transmitting structure. The drive member has a slot with an open end for accommodating the shaft of the counterbalancing mechanism and a releasable coupling structure that connects the drive member with a collar attached to the counterbalance spring, such that rotation of the drive member applies a rotational force to the spring. In this way, a motor within the power transmitting structure is used to drive the collar and tension the spring. A socket or pipe adapter may be connected to the drive member to allow the power tool to rotate nuts, bolts and pipes. While this device can be provided to an installer for multiple uses and does not need to be shipped with each door, not all doors, such as do-it-yourself doors, are installed by a professional installer making this device expensive for a single use. The device is rather heavy and bulky and includes a significant number of components making it expensive to ship with each door, leaving the do-it-yourself consumer to manually tension the counterbalance spring.
Another known design consists of a collar that can be slipped over a rod around which the counterbalance spring is wound, fitted with a pair of ratcheting mechanisms and a device to hold the same in place while the ratchets are used. The device also includes a boss for hooking into the spring collar and applying the correct tension through the use of the ratcheting arrangement. Means for attaching the collar to one end of the spring are provided and, thus, the spring is tensioned through use of the ratcheting mechanism.
Another known device includes a tool for applying rotational force to a coiled torsion spring of a door counterbalancing mechanism. The tool includes a split housing fixedly mounted on the winding cone of the torsion spring. This housing has a sprocket mounted thereon. On either side of the sprocket are annular grooves that respectively connect to a right hand operated and left hand operated ratchet tool. These ratchet tools are to be used sequentially in unison to create tension within the spring.
Still another design is an arrangement for an overhead garage door that includes an adapter used for tensioning the coil spring. The adapter has a body that may be mounted on a rotatable shaft that supports the coil spring and be non-rotatably attached to the end of the coil spring and the rotatable shaft. The attachment to the shaft is a releasable connection and the body has splines or projecting abutment surfaces so that two wrenches may have their jaws closely surround and engage the splines on the body. The wrenches have releasable latches that are designed to engage and disengage the splines on the adapter body. To tension the door, the splines are engaged and rotated with the wrenches in an alternate manner.
With the previously discussed designs, it is not practical to ship the specialized tools with each door. Also, when performing maintenance on doors, these specialized tools may be lost and require replacement when the springs need retensioning. Also, excessive wear may make it impossible to use the specialized tools to retention the spring. As a further practical consideration, these tools are normally used when one is standing on a ladder and tools that are bulky or require two hands to operate make it difficult to maintain one's balance on a ladder, thereby resulting in a safety concern.
Another approach to tensioning such counterbalance systems contemplates a wormgear/worm reducer that allows use of an electric power tool, such as a drill motor, to adjust tension in the spring. Such devices are normally made integral with the counterbalance system. The cost of the winding components adds significantly to the overall cost of the door, thereby making the system more expensive than doors with conventional counterbalance systems. While these systems are very capable of tensioning the door, they lack the physical feedback of the door tension found in the manually operated devices. Consequently, such winding devices need a counter that indicates the applied or removed tension without adding significant cost to the door. As a further disadvantage, since these mechanisms are normally integral with the counterbalance system, they may not be used to tension different doors. Therefore, there is a further need for a system that may be used on many different doors.
One known example of a counterbalance mechanism having a worm-gear assembly for a sectional garage door includes an elongated shaft mounted above the door opening and supporting spaced apart cable drums connected to respective cables that transmit a counterbalance force to the door. Opposing torsion springs are connected to the cable drums at one end and hub members at the other end that are axially slidable but non-rotatable relative to the shaft. The drums are provided with detachable bushing members for engagement with support brackets. The shaft is connected to a non-reversible worm-gear drive at one end. The worm-gear drive may be actuated to selectively vary the torsional winding of the counterbalance springs by rotating the worm and ring gear meshing therewith. The worm-gear drive may be detachably mounted on one or other end of shaft support brackets and a lock plate is supported on the shaft and engagable with the bracket to prevent rotation of the shaft when the mechanism is removed. Spring biased rollers are provided to compensate for skewing of the door caused by the shaft loading both springs which do not have identical characteristics.
Yet another known worm-gear counterbalance system includes a tubular shaft mounted on wall brackets carrying spaced apart cable drums operable to wind counterbalance cables thereon and counterbalance the weight of the door. Torsion springs inner connect with the cable drums and a spring winder tube is sleeved over the springs and connected to the wall brackets by a winding mechanism. The winding mechanism includes a support plate having spaced apart tabs adapted to register in corresponding slots formed in the wall bracket. The winding mechanism further includes a worm-gear drive including a ring-gear which is connected to one end of the winder tube by arrangement of radially inward projecting key portions and a bore of the ring gear, which register with axial grooves formed in the winder tube and are adapted to slide into transverse slots intersecting the grooves. A removable lock pin is engagable with the ring-gear or the worm of the worm-gear drive.
In still another worm-gear counterbalance system design, similar to the previously described design, spring winding and protected cover tubes are sleeved over the springs and connect to support brackets by a worm-gear drive winding mechanism. The worm-gear drive winding mechanism rotates the tubes to effect winding of the torsion coil springs through hub assemblies but prevents rotation of the tubes during normal operation of the counterbalance system. The cable drums and spring hub assemblies may be supported on an elongated synchronizing shaft or torque transfer shaft extending between and supported on the wall brackets.
It is an object of the present invention to provide an improved tensioning tool for winding a counterbalance spring in a sectional door system. Another object of the present invention is to provide such a tool that includes a counting assembly indicating the amount of tension applied or released from the counterbalance spring. It is another object of the present invention to provide such a tool that may be used in connection with a non-powered or powered wrench or driver.
It is still another object of the present invention to provide a tensioning tool that will accommodate a plurality of door heights. Yet another object of the present invention is to provide such a tool that is easily attachable to and detachable from a counterbalance system. Another object of the present invention is to provide a tensioning tool that may be used to wind either the right or left hand wound springs of a counterbalance system. Still another object of the present invention is to provide such a tool that can be used to wind torsion or extension springs. Yet another object of the present invention is to provide such a tool that provides tension turn count for both winding and unwinding springs. A further object of the invention is to provide such a tool which has a housing with a stop operable independent of the counterbalance support bracket to prevent rotation of the tool during tensioning of the counterbalance system by engaging the door frame or hardware overlying the door frame by virtue of the relative sizing and/or positioning of the counterbalance system, the tool and the door frame.
In light of at least one of the foregoing objects, the present invention provides a door system including, a door movably mounted on a track assembly, a counterbalance system connected to the door and having at least one spring, a tool adapter proximate at least one end of the counterbalance system, a detachable winding assembly adapted to selectively engage and selectively rotate the tool adapter to adjust tensioning of the spring, and a locking assembly interacting with the counterbalance system to maintain a selected tensioning of the counterbalance system upon detaching the winding assembly from the tool adapter.
A tensioning tool according to the concepts of the present invention is shown in the accompanying Figs., and generally indicated by the letter T. The tensioning tool T is used in connection with a door system, generally indicated by the numeral 10, that is mounted to a framework, generally indicated by the numeral 11, made up of a header 12 and a pair of spaced vertical jambs 14. The door system 10 includes guide tracks, generally indicated by the numeral 15, which receive a door D, movably mounted thereon. The framework 11 defines an opening in which the door D is selectively moved from a closed vertical position depicted in
In the example shown, door system 10 includes a counterbalance system, generally indicated by the numeral 20, used to offset the weight of the door D. Counterbalance system 20 is shown mounted on the header 12 and includes a pair of cable drums 21 carried on an axle 22, which may be in the form of a solid shaft or hollow tube, rotatably supported on support brackets 24. The cable drums 21 carry a cable C used to couple the door D to the counterbalance system 20 in a manner well known in the art.
To facilitate raising and lowering of the door D, the counterbalance system 20 may include a counterbalance spring 25 (
The tensioning tool T has a winding assembly, generally indicated by the numeral 30, that may be configured to operate with tool adapter 26 to adjust the tension on counter balance spring 25 (
With the winding assembly 30 coupled to the counterbalance spring 25, tensioning of the spring 25 may be performed by rotating the tool adapter 26. To that end, the first gear 35 is rotatably mounted within a housing, generally indicated by the numeral 40, and has a first axis of rotation A corresponding to that of the tool adapter 26 (
The second gear 37 includes at least one boss 38 adapted to couple the second gear 37 to a standard tool, such as a drill or driver. For example, a hexagonal boss 38 may extend from one or both ends of the second gear 37. With a boss 38 located at both ends of second gear 37, the winding assembly 30 may be attached at either the left end or right end side (
The second gear 37 is mounted such that it operatively interacts with the first gear 35 to cause rotation thereof in either a clockwise or counterclockwise direction and like the first gear 35 is rotatably mounted within the housing 40. As shown, cylindrical surfaces 38′ at either end of the second gear 37 may be received within bushings 43 mounted on the housing 40. While the bushings 43 may be integrally formed with the housing 40, as shown in the drawings, removable bushings 43 may be used such that they may be easily replaced in the event of damage or wear. In the example shown, a pair of substantially annular bushings 43 are provided. Bushings 43 may have radially outward extending flanges 44 formed at each end thereof and axially spaced from each other to seat the bushings 43 within a generally circular ribs 45 that extend from the housing 40. The bases 46 of bushings 43 may be flattened and fit within recesses 47 formed in housing 40 to prevent rotation of bushing 43. As shown, the housing 40 may be formed in two pieces 41, 42 that are joined to encompass the bushings 43 therebetween. When the two pieces 41,42 of housing 40 are joined, the first gear 35 and second gear 37 are enclosed and maintained in meshing engagement. The bosses 38 extends axially outwardly of bushings 43 and are readily accessible for tensioning spring 25. It will be appreciated that the bosses 38 need not extend outside of the housing 40 and may be accessible through an opening in the housing 40.
A counter assembly according to the concepts of the present invention, generally indicated by the numeral 50, which may be part of tensioning tool T, is operable with the winding assembly 30 to quantify the tension on the counterbalance system 20 and convey that information to the user. With reference to
To facilitate rotation of the counter cam 53, an annular collar 60 may extend axially outwardly from the housing 40 surrounding bore 58 and counter cam 53 may include an axially inwardly extending cuff 61 that fits over the collar 60 and is rotatable thereon. Counter cam 53 has a plate like end that includes a flange 62 extending radially outwardly of the cuff 61. As best shown in
Flange 62 of counter cam 53, on its inward axial side, abuts a ring 65 located radially outwardly of the collar 60 of housing 40. Ring 65 provides a surface on which the counter 55 may rotate and may define a circular groove 67 located axially inwardly of its axial outer surface 66 that receives detents 68 formed on the interior of the counter 55. In this way, the counter 55 may be snap fit onto ring 65. A pin 70 may be pushed through an opening 71 defined in the center of an endwall 73 of counter 55 and into the counter cam 53 to assure that the counter cam 53 remains in contact with the counter 55.
When assembled, the winding assembly 30 is coupled to the tool adapter 26 of the counterbalancing system 20 and torque is applied to the second gear 37 at boss 38 by means of a powered or nonpowered tool. This results in rotation of first gear 35 and counter cam 53 causing on the one hand the first gear 35 to tension the counterbalance spring 25 and on the other hand the counter cam 53 to wobble the gear teeth of rotating gear 52 over the fixed gear 51, such that, the counter 55 senses and responds by rotating an amount equal to the pitch of the fixed gear 51. The counting function is the same regardless of the direction of rotation. In this way, the amount of tension may be tracked as it is applied or released from the spring 25. This information is displayed in the movement of the counter 55 as reflected by the attached scale 56.
As an alternative to monitoring tension with the mechanical counter 50, tension may be monitored electronically. Referring to
To provide for use of the counter assembly 150 with multiple doors, the encoder 151 is removable from the counter balance system 20, and may include a bracket 152 having a downwardly extending ear 154 that is laterally spaced from the encoder 151 to slidably fit over the support bracket 24. Conventionally, the display unit 155 may be held by the user or hung on a fastener or other convenient projection. Thus, when the installer is finished tensioning the door D, the encoder 151 may be slid off the support bracket 24 and the display unit 155 removed therewith.
Thus, it should be evident that the tensioning tool and counters for a counterbalance system for sectional doors disclosed herein carries out one or more of the objects of the present invention set forth above and otherwise constitutes an advantageous contribution to the art. As will be apparent to persons skilled in the art, modifications can be made to the preferred embodiments disclosed herein without departing from the spirit of the invention, the scope of the invention herein being limited solely by the scope of the attached claims.
This is a divisional application of application Ser. No. 10/790,447 filed Feb. 26, 2004, which is incorporated herein by reference.
Number | Date | Country | |
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Parent | 10790447 | Feb 2004 | US |
Child | 12283806 | US |