Abstract:
A self-adapting refuse receptacle lift has a carriage for raising and dumping the contents of a refuse receptacle into a collection load box or refuse gathering vehicle. The carriage is carried on extending arms, the rotation of which may be controlled with a hydraulic or other powered drive device. The carriage includes attachments comprising a pair of moveable clamp arms. The clamp arms have self-adapting features so that a variety of receptacles of different sizes and shapes may be lifted by the apparatus. Sequencing elements rotate the clamp arms down from a vertical stored position into a horizontal position for clamping a receptacle to be dumped. Then, the entire carriage is raised for inverting and dumping and the contents of the receptacle, and then reverse operations follow, whereby the clamp arms return to an upright stored vertical position to be out of the way during the movement of a refuse collecting vehicle.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from and is related to provisional application, serial No. 60/179,233 filed Jan. 31, 2000. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to refuse receptacle lifts for use with a refuse collection load box or a refuse gathering vehicle. More specifically, the present invention relates to a low or slim profile self-adapting apparatus, i.e., that is capable of lifting refuse receptacles of varying sizes and shapes using a self-adapting clamp arm and then dumping the contents of the refuse receptacle into a load box or other refuse container. 
     BACKGROUND OF THE INVENTION 
     Receptacles for the receipt, temporary storage, and/or transport of refuse are available in a variety of shapes and sizes. While the traditional, round metal garbage can is still utilized, many have been replaced with generally larger and lighter receptacles constructed from various plastics and other synthetic materials. Features may include for example hinged covers, locking covers, wheels, and handles in various locations and configurations. Capacities may range for example from 30 gallons to 95 gallons. 
     Typically, on the day of collection, the receptacle is placed near curb-side for pick-up involving a gathering vehicle. The refuse collected in such conventional receptacles from residences and businesses must be then transported usually by a commercial or municipal service to a treatment or disposal site. Generally, a refuse gathering vehicle equipped with a compactor is used to transport the contents of the receptacle from curb side to such a later site. Consequently, the receptacle&#39;s contents must be conveyed to a designated compartment on the gathering vehicle. Current conventional containers can weigh as much as 200 pounds when loaded. Various receptacle dumping mechanisms exist for delivering a receptacle&#39;s contents into the compartment of a gathering vehicle. For example, dumping mechanisms that include a movable carriage configured to receive a receptacle and dump its contents into a gathering vehicle are described in Brown et al. (U.S. Pat. No. 3,804,277), Shive (U.S. Pat. No. 3,894,642), and Wyman et al. (U.S. Pat. No. 4,479,751). The disclosures of such patents are incorporated herein by reference. 
     While such types of lift devices and associated receptacles generally permit mechanized dumping (as opposed to manual), various drawbacks and inefficiencies persist. For example, some of such prior art receptacle dumping mechanisms typically may tend to dump the contents of the receptacle only near the very back of the refuse-receiving opening of the garbage truck. A typical garbage truck has a large opening located at its rear to provide access to a relatively large trash container carried on the truck. A dumping apparatus as discussed above is usually mounted adjacent such opening, such as at or on a rear bumper of a truck. A built-in trash compactor is also typically present in the container for compacting refuse therein. If the contents of the receptacle are dumped only at the very back of such refuse-receiving opening (as is often the case), a compaction cycle (i.e. operation of the built-in compactor of the garbage truck) must be run after almost each successive receptacle dumping so as to push the dumped contents forward, i.e. away from the very rear of the garbage truck, to make room for the next dumping. Having to frequently repeat compacting cycles is very time consuming, since a garbage truck normally would include a great number of stops at relatively short intervals on its route, and also adds to wear and tear on the compactor equipment. 
     Another drawback of some of such prior art mechanized dumping devices is the sheer size of the unit itself. Many prior art dumping devices have a width (i.e. projection from the rear bumper of the garbage truck) in a range of about 16 to 20 inches, not including the trash receptacle mounted for dumping. A safety hazard is thus presented by structure which projects substantially from the rear of the vehicle, particularly since it cannot be seen by the driver of the truck. 
     Also, as an additional practical matter, garbage trucks outfitted with such prior art (relatively thick) dumping apparatuses for smaller residential trash receptacles cannot be simultaneously used for dumping larger commercial trash dumpsters. Such dumpsters are normally pivoted against pivot members mounted at the rear of the truck itself while being winched upward with a powered cable mounted at the top of the garbage truck. Such dual use of a garbage truck is normally not possible with the typical prior art residential receptacle dumping device because there is not sufficient clearance for the commercial dumpster to be pivoted on the truck-mounted pivot members around the prior art residential dumping devices due to their relatively thick width. 
     Additionally, some refuse-gathering vehicles have their refuse-receiving openings on the sides of the truck, rather than at their backs. Such side-loading vehicles typically cannot safely use such prior art dumping devices again because they generally extend too far from the side of the truck. 
     Commonly owned U.S. Pat. No. 4,773,812 discloses a receptacle lift and slim profile power unit addressing certain of the disadvantages of typical receptacle dumping apparatuses referenced above. The width of such a lift is substantially less than typical receptacle dumping apparatuses and includes a power drive unit that is also of reduced width. Such reduced profile allows such lift configuration to be used in conjunction with existing refuse gathering vehicles to overcome problems with the typical receptacle lifts above discussed. Such lift may also be used to dump receptacle contents a predetermined distance up into a refuse gathering vehicle so that the vehicle&#39;s compactor unit does not require operation after each dumping cycle. It may also be installed on a gathering vehicle so as not to interfere with the lift mechanisms that may already be present on a gathering vehicle for dumping other types of containers such as larger bins typically not used for residential, curb-side pick-up. The disclosure of U.S. Pat. No. 4,773,812 is incorporated herein by reference. 
     Due to the various unique geometries of the receptacles available and in use, typical prior art lifts may not be functional with all receptacle types currently encountered during a refuse pick-up. For example, the handles on various receptacles may be located at different heights, have different shapes, and be positioned at different orientations on a receptacle. The height, width, and overall volume of each receptacle may vary widely. Commonly owned U.S. Pat. Nos. 5,308,211 and 5,333,984 disclose various receptacle types and certain lifter variations. The disclosures of all such patents are hereby incorporated herein by reference. The container may be structured for dumping by a correspondingly configured lift. Similarly, the lift in place on a particular gathering vehicle may only be configured to receive a receptacle meeting the particular specifications of that lift. While generally uniform receptacles on any given pick-up route could be used to ensure the functionality of the lift with all receptacles encountered by the gathering vehicle, such a requirement may not be practical. Even though existing prior art lifts may be modifiable for a given receptacle type, a lift capable of adapting automatically to a variety of container types without prior modification and while in use during a refuse pick-up route would provide additional benefits over existing apparatuses. Such a lift that also incorporates the features of U.S. Pat. No. 4,773,812, so as to overcome the limitations of the typical receptacle lift as above identified would be even more desirable. 
     SUMMARY OF THE INVENTION 
     The present invention provides an adaptable, refuse receptacle lift for use with a refuse collection load box or a refuse gathering vehicle. A unique self-adapting clamp arm is used to provide a lift that automatically self-adapts to the size and shape of a variety of receptacles while the lift is in use and without requiring prior modifications each time a different receptacle type is encountered. By incorporating features disclosed in U.S. Pat. No. 4,773,812, the present invention also provides a lift that overcomes problems associated with typical receptacle lifts as above identified. By way of example, the present lift is of a reduced profile and is also capable of dumping a receptacle&#39;s contents a predetermined distance up into a refuse gathering vehicle so that the vehicle&#39;s compactor unit does not require operation after each dumping cycle. 
     In addition, the present invention relates to certain sequencing features, so that self-adapting clamp arm features are also operated for maximum clearance during non-use, for safer vehicle movement and operation. 
     Additional objects and advantages of the invention are set forth in, or will be apparent to those of ordinary skill in the art from the detailed description herein. Also, it should be further appreciated that modifications and variations to the specifically illustrated and discussed features or materials hereof may be practiced in various embodiments and uses of this invention without departing from the spirit and scope thereof, by virtue of present reference thereto. Such variations may include, but are not limited to, substitution of equivalent means and features or materials for those shown or discussed, and the functional or positional reversal of various parts, features or the like. 
     Still further, it is to be understood that different embodiments, as well as different presently preferred embodiments, of this invention, may include various combinations or configurations of presently disclosed features or elements, or their equivalents (including combinations or configurations thereof not expressly shown in the figures or stated in the detailed description). 
     While various power drive units and lifting apparatuses embodying different combinations of presently disclosed features may be constructed, applying the teachings disclosed herein, to arrive at various embodiments of the present invention, one exemplary lift apparatus of the present invention includes: 
     a support frame adapted to be mounted onto a container; 
     a hydraulic actuator, attached to the support frame, having a rotatable output shaft, and configured for controllably positioning the rotary orientation of such output shaft; 
     a carriage adapted for supporting a receptacle, such carriage being pivotally supported relative to the support frame; 
     a pair of idler arms for pivotally supporting such carriage relative to the support frame; 
     a pair of torque arms for pivotally supporting such carriage relative to the output shaft; 
     a clamp arm shaft attached to such carriage and rotatable relative to the carriage; 
     a pair of self-adapting clamp arms, each clamp arm having a receptacle receiving end and a non-receptacle receiving end, each clamp arm being pivotally connected near the non-receptacle receiving end to the rotatable clamp arm shaft, whereby the such clamp arms may be controllably rotated relative to the carriage, each clamp arm being configured to adapt to the size and shape of a variety of receptacles for lifting by the apparatus; 
     a first hydraulic drive attached to the carriage, having a reciprocating shaft pivotally connected to the rotatable clamp arm shaft, such first hydraulic drive controllably positioning the rotary orientation of the clamp arm shaft; 
     a second hydraulic drive pivotally connected to the non-receptacle receiving end of the pair of self-adapting clamp arms, whereby such clamp arms may be controllably opened and closed; 
     wherein the hydraulic actuator, the first hydraulic drive, and the second hydraulic drive are controllably operated, and in a desired, predetermined sequence, so as to cause controlled rotation of the self-adapting clamp arms between an upright stored position and a position for the receipt of a receptacle, causes controlled opening and closing of the self-adapting clamp arms for securing a receptacle; and causes controlled pivoting of the carriage on respective ends of the idler arms and torque arms, between a lowered, upright position of the carriage for receiving a receptacle and a relatively raised, inverted position of the carriage for emptying the contents of a receptacle. 
     Another exemplary embodiment of a receptacle lift apparatus in accordance with the present invention, includes: 
     a base adapted for mounting the lift onto a container; 
     a first power means, attached to such base, having a rotatable output shaft, such first power means controllably positioning the rotary orientation of such output shaft; 
     a carriage pivotally supported relative to the base; 
     dual paired projection arm means, pivotally associated with the base and the output shaft, respectively, for supporting and selectively positioning the carriage during the lifting and conveying of a receptacle, and configured so as to dump the contents of a receptacle received by the lift; 
     a positioning shaft, connected to the carriage and rotatable relative to the carriage; 
     an adaptable embracing means for receipt of a receptacle, pivotally connected to the positioning shaft such that the rotary orientation of the embracing means may be controlled by the positioning shaft, and adaptable to the size and shape of a receptacle to be lifted; 
     a support means, connected to the positioning shaft, for providing support to a receptacle received by the lift; 
     a second power means, attached to the carriage, and pivotally attached to the positioning shaft, whereby such second power means may control the rotary orientation of the positioning shaft; 
     a third power means, connected to the adaptable embracing means and controllably pivoting the embracing means about the positioning shaft such that a receptacle may be controllably embraced; 
     wherein selective operation of the first, second, and third power means causes in desired sequence controlled rotation of the adaptable embracing means, causes controllable embracing of a receptacle by the embracing means, and causes controlled movement of the carriage on the dual paired projection arm means relative to the base between a lowered position of the embracing means for receipt of a receptacle and a relatively raised, and inverted position for the emptying of any contents within the receptacle. 
     Still another example of a receptacle lift in accordance with the present invention, for lifting and dumping the contents of a receptacle into a container, includes: 
     a mainframe having a first side and a second side, such first side being adapted for attachment to the container; 
     a motor, attached to the second side of the mainframe, having a rotatable output shaft, and configured for controllably positioning the rotary orientation of such output shaft; 
     a plate pivotally connected to the second side of the mainframe; 
     a first pair of arms, pivotally connected to the second side of the mainframe and pivotally connected to the plate; 
     a second pair of arms, fixedly connected to the rotatable output shaft and pivotally connected to the plate; 
     a clamp arm shaft secured to the plate and rotatable relative to the plate; 
     a least one clamp arm, such clamp arm including an arcuate support member having a first end and a second end, such support member pivotally connected near the first end to the clamp arm shaft such that the rotary orientation of such clamp arm may be controlled by the clamp arm shaft, such clamp arm also including a band of flexible material connected near the first end and near the second end of the support member arm and spanning in between such ends, whereby upon contacting a receptacle, such clamp arm may adapt to the size and shape of the receptacle for securing the receptacle during lifting and dumping of the receptacle; 
     a first hydraulic cylinder attached to the plate and pivotally attached to the clamp arm shaft and configured such that the extension and retraction of the hydraulic cylinder controls the rotary orientation of the clamp arm shaft; 
     a second hydraulic cylinder pivotally connected near the first end of the clamp arm and configured such that the extension and retraction of the hydraulic cylinder controls the pivoting of the clamp arm about the clamp arm shaft, whereby such clamp arm may be pressed against the receptacle to secure the receptacle to the lift; 
     wherein selected operation of the motor, the first hydraulic cylinder, and the second hydraulic cylinder causes in sequence the clamp arm to move into a position so as to secure a receptacle to the lift; and causes the lift to move the receptacle between a relatively lowered position and a relatively upright and inverted position where the contents may be dumped into the container. 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following description. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the principles of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: 
     FIG. 1 is a perspective view of an exemplary self-adapting refuse receptacle lift in accordance with the present invention, in a retracted position mounted onto a container; 
     FIG. 2 is a perspective view of the self-adapting refuse receptacle lift of FIG. 1 embracing one example of a receptacle; 
     FIG. 3 is a perspective view of the self-adapting refuse receptacle lift of FIG. 1 embracing an exemplary receptacle in an inverted position; 
     FIG. 4 is a perspective view of the self-adapting receptacle lift of FIG. 1 in isolation showing in enlargement the clamp arms in an extended position; 
     FIG. 5 is front, perspective and partial cut-away view of the self-adapting receptacle lift of FIG. 1 in enlargement; 
     FIG. 5A is a top view in enlargement of the right corner of the self-adapting receptacle lift of FIG. 1; 
     FIG. 5B is a top view in enlargement of the left corner of the self-adapting receptacle lift of FIG. 1; 
     FIG. 5C is a plan view of the left side of the self-adapting receptacle lift of FIG. 1; 
     FIG. 5D is a plan view of the back side of the self-adapting receptacle lift of FIG. 1; 
     FIG. 6 is a front, perspective view in enlargement of the left and bottom corner of the self-adapting receptacle lift of FIG. 1; 
     FIG. 7 is a top, partial perspective view, depicting operation of the clamp arms of the self-adapting receptacle lift of FIG. 1; 
     FIG. 8 is a partial schematic of an exemplary hydraulic control system for the present invention; and 
     FIG. 9 is a schematic of various features of an exemplary hydraulic control system in accordance with the present invention. 
    
    
     Repeat use of reference characters throughout the present specification and appended drawings is intended to represent same or analogous features or elements of the invention. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference now will be made in detail to the embodiments of the invention, one or more examples of which are set forth below. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used on or with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations. Other objects, features and aspects of the present invention are disclosed in or are apparent from the following detailed description. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention. 
     FIG. 1 illustrates one embodiment of a self-adapting refuse receptacle lift  40  configured for use with an exemplary refuse container  30 . Container  30  includes an opening  32  into which the contents of a receptacle may be dumped using receptacle lift  40 . Container  30  may be used in conjunction with a refuse gathering vehicle as set forth, for example, in U.S. Pat. No. 5,308,211, which is incorporated herein be reference. Lift  40  is shown in the retracted position where it may be stored and where it assumes a relatively slim profile. FIG. 1 is but an example of one application of lift  40 ; the present invention may be used in a variety of other applications using the teachings disclosed herein. 
     FIG. 2 shows lift  40  in isolation embracing an exemplary receptacle  34 . Lift  40  and receptacle  34  are depicted in the position lift  40  and receptacle  34  occupy both at the point prior to lifting receptacle  34  and at the point after the contents of receptacle  34  have been dumped into container  30 . FIG. 3 shows lift  40 , again in isolation, embracing receptacle  34  in an inverted position in which contents from receptacle  34  may be dumped into container  30 . 
     Referring now to FIGS. 1 thru  4 , this particular embodiment of lift  40  includes a support frame  64  for mounting onto a surface, such as the side of container  30 . Support frame  64  has two sides, a first side  66  and a second side  68 . First side  66  is adapted to be secured, such as by welding or with bolts or the like, to container  30 , a refuse-gathering vehicle, or other structure with which lift  40  is to be used. Other installations of lift  40 , including those for other than the express use of lift  40  as a trash receptacle dumping device, come within the scope of the present invention. 
     Second side  68  of support frame  64  supports an exemplary actuator  50  that is used to pivot the lift  40  between the relatively lowered position of FIG.  4  and the relatively raised and inverted position of FIG. 3, as more fully described below. In order to maintain the relatively slim profile of lift  40  in its retracted position (FIG.  1 ), low profile actuator  50  as depicted in FIG. 4 may be preferred. One such actuator that may be used in the present invention is disclosed in U.S. Pat. No. 4,773,812, the disclosure of which is incorporated herein by reference. In general, U.S. Pat. No. 4,773,812 describes a hydraulically-actuated, two cylinder, rack and pinion mechanism. An output shaft is passed through both cylinders and is rotated by the action of the cylinders. Accordingly, the selective operation of the cylinders may be used to control the rotary orientation of the output shaft of actuator  50 . However, a variety of actuating mechanisms, including non-hydraulic, may be used to power the pivoting of lift  40 , and this invention is not limited to a particular type or form of drive unit. Virtually any actuator  50  may be used provided the output shaft may be controllably rotated and configured to operate the lift as more fully discussed below. 
     A pair of pivot points  72  are also supported by the second side  68  of support frame  64 . Pivot points  72  support a pair of idler arms  74  for pivotably supporting a carriage  60 . FIG. 5 illustrates carriage  60  partially cutaway to permit illustration of the operative structure typically behind carriage  60 . While it will be described in parts herein, this operative structure is also described in U.S. Pat. No. 4,773,812, which is incorporated herein by reference. Accordingly, idler arms  74  are also connected to the carriage  60  at a second pair of pivot points  76 . The carriage  60  is therefore movable with respect to support frame  64  by pivoting upon arms  74 . 
     Carriage  60  is also connected to the output shaft of the actuator  50  through a pair of torque arms  78 . A pair of pivot points  82  pivotably connect torque arms  78  to carriage  60 . The other ends of torque arms  78  are fixedly connected to the output shaft of actuator  50 . As shown in FIG. 8, the output shaft  52  of actuator  50  includes two respective ends  54  to which the ends of torque arms  78  may be respectively secured. FIGS. 5A and 5B provide further illustration of the connection of torque arms  78  and idler arms  74 . 
     As shown in FIG. 5C, the respective lengths of idler arms  74  and torque arms  78 , together with the displacement of the pivot points  72 , pivot points  76 , pivot points  82 , and the fixed connection to output shaft  52 , determines a distance which the front edge  51  (FIG. 3) of carriage  60  is projected behind the first side  66  of support frame  64  and, therefore, the distance receptacle  34  is projected when lift  40  is in its fully raised and inverted position. This lateral translation of receptacle  34  serves the useful purpose of projecting receptacle  34  a predetermined distance behind support frame  64 . When the lift is connected to the receiving opening of a refuse gathering vehicle, this allows the contents of receptacle  34  to be dumped forwardly into the truck away from the very rear of the truck. As a result, the compaction unit of the truck may be advantageously operated less frequently, as was more fully discussed in the Background of the Invention. FIG. 5C presents a side view of the embodiment depicted in FIG. 5, illustrating the respective arm lengths and pivot point placements. FIG. 5D also provides a perspective view of the embodiment depicted in FIG. 5, taken from a view point opposite to that of FIG.  5 . 
     Carriage  60  also supports a clamp arm shaft  100 . The clamp arm shaft  100  is rotatable with respect to carriage  60  and is connected to the carriage  60  at rotatable points  110 , which may be constructed from bearings inside bearing mounts or the like. Referring to FIG. 6, the clamp arm shaft  100  is controllably positioned using a first hydraulic cylinder  120  that is attached at one end to the carriage  60  and pivotably connected at the other end to clamp arm shaft  100 . A locking pin  122  is used to pivotably connect first hydraulic cylinder  120  to a pair of lever flanges  124  integrally connected to the rotatable clamp arm shaft  100 . Accordingly, selective extension and retraction of first hydraulic cylinder  120  allows the rotary orientation of shaft  100  to be controlled through changing the position of lever flanges  124  and thus the rotary orientation of shaft  100 . While a hydraulic cylinder  120  is shown for the embodiment depicted in FIG. 6, any drive means capable of controllably positioning the shaft  100  may be used without changing the scope of the present invention. 
     Referring to FIG. 7, a pair of self-adapting clamp arms  130  are pivotably connected respectively to each end of clamp arm shaft  100 . Clamp arms  130  each include an arcuate support member  132  having a first end  134  and a second end  136 . Each arm  130  is pivotably connected to shaft  100  at a pivot point  138  located near first end  134  of arcuate support member  132 . A band of flexible material  140  is attached to each support member  132 . Material  140  is connected to both first end  134  and second end  136  of each support member  132  so as to span between the ends of support member  132 . The material  140  may be constructed of any sufficiently flexible materials, including a composite or laminate of different materials. For example, material  140  may include a composite of rubber, vinyl, metal belts, and the like. By utilizing a flexible material, lift  40  adapts to the size and shape of various receptacles  34  (depicted in broken lines in FIG. 7) that may be lifted. More specifically, upon closing self-adapting clamp arms  130 , flexible material  140  adapts to the shape of receptacle  34  while maintaining enough rigidity, with reinforcement from support member  132 , to secure the receptacle  34  for dumping. The arcuate shape of support member  132  provides room for flexible material  140  to displace and deform so to adapt to a particular receptacle&#39;s shape. 
     Clamp arms  130  are not limited to the shape and construction depicted in FIG.  7 . The shape, construction, and operation of the clamp arms  130  may be varied to provide for an adaptable embracing means within the scope of the present invention. By way of example only, support member  132  may assume nonarcuate shapes and flexible material  140  may be attached to support member  132  at locations other than ends  134  and  136 . Furthermore, a flexible or resilient material, such as foam or rubber padding, could be attached to the entire length of support member  132  to provide another means by which support member  132  could adapt to the shape of a receptacle  34 . Accordingly, the present invention provides a lift  40  adaptable to the shape and size of various containers and is not limited to the particular adapting means disclosed in FIG.  7 . 
     As also show in FIG. 7, a second hydraulic cylinder  142  is pivotably connected to each support member  132  near first ends  134  thereof respectively. Selective extension and contraction of second hydraulic cylinder  142 , as shown by the arrows in FIG. 7, controls the pivoting of the clamp arms  130  about pivot points  138  and empowers clamp arms  130  to selectively embrace a receptacle for lifting. As shown in FIG. 5, a connecting rod  144  is pivotably connected at each end respectively to clamp arms  130 . While connecting rod  144  is connected near the first end  134  of each support member  132 , this pivoting connection is on opposite sides of the pivot points  138 , respectively, of each clamp arm  130 , as depicted in FIG.  1 . During the extension and retraction of second hydraulic cylinder  142 , connecting rod  144  ensures that clamp arms  130  open and close in unison as opposed to only moving one clamp arm  130  or moving the clamp arms  130  unevenly. Connecting rod  144  may also be configured such that its length is adjustable, whereby the unclamped width between second ends  136  of clamp arms  130  may be determined. While a hydraulic cylinder  142  is depicted for this embodiment, any drive means for controllably pivoting clamp arms  130  about pivot points  138  may be used within the scope of the present invention. 
     As shown in FIG.  1  and FIG. 6, the clamp arm shaft  100  also supports bumper  62 , which is fixedly attached to shaft  100 , and oriented along shaft  100  so as to align with clamp arms  130 . Accordingly, upon the controlled rotation of clamp arm shaft  100  using first hydraulic cylinder  120 , bumper  62  rotates in alignment with clamp arms  130 . Bumper  62  thereby provides additional stabilizing support to receptacle  34  embraced within the clamp arms  130 , as shown in FIG.  7 . Other means may be used to provide such support to receptacle  34  within the meaning of the present invention. For example, carriage  60  may include a stabilizing means such as a bumper or a flexible rest located upon carriage face  63 . 
     In operation, the power means of lift  40 , more specifically actuator  50 , first hydraulic cylinder  120 , and second hydraulic cylinder  142 , may be selectively operated and powered by a variety of hydraulic control systems. For example, each power means could be controlled by single hydraulic valves dedicated respectively to each drive means. Additionally, and by way of example only, each valve may be integrated into a control system for automatically sequencing all valves through a cycle of lifting receptacle  34  and dumping its contents. 
     The present invention may include a hydraulic control system  148  as depicted in FIG. 8. A dual hand valve  150  is hydraulically connected to a sequencing control valve  152  and a dual check valve  154 . In turn, dual check valve  154  is connected to actuator  50  with output shaft  52  having ends  54 . First hydraulic cylinder  120  and second hydraulic cylinder  142  are also connected to control valve  152 . A supply line  158  supplies hydraulic fluid from a pressurized source, such as a pump, to flow regulator  156 , which in turn supplies dual hand valve  150 . A return line  160  allows hydraulic fluid to flow from dual hand valve  150  to a reservoir such as a storage tank. Dual hand valve  150  may be mounted at a location accessible to the user, such as the side of a refuse gathering vehicle or a refuse container. 
     FIG. 9 is a schematic of hydraulic control system  148  using conventional symbols and connection lines understood and used by those having ordinary skill in the art. Hydraulic fluid is supplied from a pressurized source, such as a pump, using supply line  158 . Flow regulator  156  maintains a relatively constant outlet flow of fluid to dual hand valve  150 . For the particular embodiment of the invention being described, flow regulator  156  may accept an inlet flow of between 2 to 24 gallons per minute with a pressure between 1800 to 3000 pounds per square inch. Under these conditions, flow regulator  156  maintains a relatively constant outlet flow of 2 gallons per minute. 
     Dual hand valve  150  consists of a first hand valve  162  and a second hand valve  164 . Both valves  162  and  164  are three positioned, spring centered, open center directional valves that are used to direct hydraulic fluid to lift  40 . Dual hand valve  150  includes a pressure release valve  200  which may be preset at the desired level to protect system components. 
     From dual hand valve  150 , hydraulic fluid may be exchanged with sequencing control valve  152 , identified generally by the broken lines in FIG.  9 . Sequencing control valve  152  includes the following elements connected as shown diagrammatically in FIG.  9 : A pair of sequence valves  166  and  168 , a needle valve  170 , a pressure reducing valve  172 , a pair of ports  174  and  176 , four check valves  178 ,  180 ,  182 , and  184 ; and four pilot operated check valves  186 ,  188 ,  190 , and  192 . From sequencing control valve  152 , fluid is exchanged with first hydraulic cylinder  120  and second hydraulic cylinder  142 . The operation of sequencing control valve  152  will be more fully described below. 
     Dual hand valve  150  also exchanges hydraulic fluid with dual check valve  154 , which includes a pair of dual pilot operated check valves  196  and  198 . From dual check valve  154 , hydraulic fluid is exchanged with actuator  50  as shown. 
     Therefore, upon supplying a pressurized hydraulic fluid to hydraulic control system  148 , first hand valve  162  may be selectively operated to pressurize port  174 , so as to direct clamp arms  130  to rotate down from the vertical position shown in FIG. 1 to the horizontal position shown in FIG. 4 by causing first hydraulic cylinder  120  to retract. As the clamp arms  130  reach the horizontal position, sequence valve  166  senses the pressure increase and shifts to direct hydraulic fluid to second hydraulic cylinder  142 , causing clamp arms  130  to clamp by extending second hydraulic cylinder  142 . Second hand valve  164  may then be selectively operated to raise carriage  60  and its attachments, including clamp arms  130 , by powering actuator  50  to as to rotate output shaft  52 , thereby lifting torque arms  78 , which rotate with output shaft  52 . Consequently, a receptacle held between clamp arms  130  may be raised, inverted, and projected so as to dump the contents of the receptacle through movements previously described. 
     After emptying the contents of the receptacle, second hand valve  164  may then be selectively operated so as to cause output shaft  52  of actuator  50  to rotate in the opposite direction, therefore reversing the direction of travel of torque arms  78  so as to lower carriage  60  and its attachments including clamp arms  130 . In this way, a receptacle within clamp arms  130  may be returned to a relatively lowered position. Next, first hand valve  162  may be selectively operated so as to pressurize port  176  of sequencing control valve  152 . Pressurizing port  176  causes clamp arms  130  to unclamp by retracting second hydraulic cylinder  142 . As clamp arms  130  reach the fully unclamped position, sequence valve  168  senses the pressure increase and shifts to direct hydraulic fluid to first hydraulic cylinder  120 , causing clamp arms  130  to return to the vertical position of FIG. 1 by extending first hydraulic cylinder  120 . 
     During all operations of the sequencing control valves  152  just described, a pressure reducing valve  172  operates to control the clamping pressure applied by clamp arms  130 . A needle valve  172  operates to control the speed of movement of clamp arms  130 . The pilot operated check valves,  186 ,  188 ,  190 ,  192 ,  196 , and  198 , operate to prevent unwanted movement of clamp arms  130 . Dual check valve  154  also prevents lifter  40  from moving in the event of a hydraulic line failure. 
     For the embodiment depicted in FIG. 1, containers having volumes as small as 30 gallons to as large as 95 gallons may be dumped using lift  40 . Additionally, receptacles and contents weighing up to 300 pounds, preferably up to 200 pounds, may be lifted with the present invention. This is provided by way of example only. The scale of the invention may be modified to achieve other specifications within the scope of the present invention. It is also to be understood that although receptacle  34  has been used in describing an embodiment, the present invention is not limited to use with a receptacle of the same or similar shape and size as receptacle  34 . More specifically, receptacle  34  is depicted by way of example only. 
     Although preferred embodiments of the invention have been described using specific terms, devices, and methods, such description is for illustrative purposes only. The words used are words of description rather than of limitation. It is to be understood that changes and variations may be made by those of ordinary skill in the art without departing from the spirit or the scope of the present invention, which is set forth in the following claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained therein.