Machine with a tilting harp

The present invention has a harp with four arms forming a parallelogram. The four arms are pivotally connected at their respective ends. Wires are secured between the side arms of the harp with holders. The harp is securely received within a channel of the machine. As such, the harp lies in a plane that is parallel to the front of the product being sliced at all times. The harp is angularly adjustable, such that the top and bottom of the harp can selectably converge or diverge as the harp tilts. The wires remain parallel during the divergence and convergence of the top and bottom of the harp. An actuator is provided for effecting the tilting of the harp. Two vertical bars can be provided for supporting the wires and minimizing deflection of the wires along their respective lengths.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a slicing machine and in particular to an improved design for an adjustably tilting harp used to slice products into exact volumes.

2. Description of the Related Art

While the present invention is useful for slicing products of any material into pieces having exact volumes, it is of particular importance in the food industry, and in the cheese industry in particular.

In a traditional setting, cheese has been produced by relatively small manufacturers. The manufacturers would typically cut the cheese manually, and individually weigh each package. This process was improved slightly with mechanical slicers. Yet, each package would still be weighed individually in order to determine the package price. Drawbacks of this approach are plentiful. For example, the process of weighing individual packages is time consuming and labor intensive. Even when mechanical weighers are used, there still is a capital requirement for purchase and maintenance of the weighing machines.

For this or other reasons, tilting harps have been developed. One example is shown in U.S. Pat. No. 6,655,248 to Johnson titled Cheese Cutting. This patent shows a cutter for cutting food into consumer-size chunks. A cutting harp is shown. Blocks of cheese are moved towards and through the harp.

The harp in this patent and in other cutters can be tilted relative the plane of the front of the cheese. This is accomplished by having an actuator adjust the angle of the harp relative the front of the cheese.

One drawback of this configuration is that it is very difficult to use a single ram to cut all the way through the cheese, especially when the harp is used in a relatively large angularly adjusted position. Instead, the ram would contact the wires near the bottom prior to pushing the top of the cheese through the harp. This is disadvantageous as additional processes are required to complete the process of cutting of the cheese. This problem is exacerbated as the angle of the tilting harp increases.

An additional drawback of this arrangement is that the angle of the harp cannot be adjusted during the middle of a cutting cycle. This is demonstrated in the Johnson patent, as weight to volume ratios are calculated after a cut, and the harp is adjusted for the next cycle. A drawback of this and other approaches is that excess product can be added to each package where until the dimensions of each cut are correct. While this may be preferable to consumers, such a result adversely affects the manufacturers.

A further drawback of this arrangement is that the force of the cheese passing through the harp places a force against harp actuator that controls the angle of the harp. Over time, the forces can shorten the lifespan of the actuator resulting in premature failure of the machine.

Thus there exists a need for a cutting machine that solves these and other problems.

SUMMARY OF THE INVENTION

The present invention relates to a slicer and in particular to an improved design for an adjustably tilting harp used to slice products into exact volumes. In a preferred embodiment, the present invention has a harp comprised of four arms forming a parallelogram. The four arms are pivotally connected at their respective ends. Wires are secured between the side arms of the harp. The harp is securely received within a channel of the machine. As such, the harp lies in a plane that is parallel to the front of the cheese at all times. The harp is angularly adjustable, such that the top and bottom of the harp can selectably converge or diverge as the harp tilts within the plane parallel to the front surface of the cheese. The wires remain parallel during the divergence and convergence of the top and bottom of the harp. An actuator is provided for effecting the tilting of the harp. The actuator acts within the plane generally parallel to the front surface of the cheese. Two vertical bars can be provided for supporting the wires and minimizing deflection of the wires along their respective lengths.

According to one advantage of the present invention, a single and simple plate can push the cheese all the way through the harp regardless of the angle of the harp. This is advantageously accomplished by having the harp tilt in a plane that is generally parallel to the front surface of the cheese.

According to another advantage of the present invention, the harp can be adjusted mid-cycle before the slicing or cutting begins. This is accomplished by determining the density (by measuring weight and volume) of the cheese and adjusting the angle of the harp to achieve a calculated piece height and accordingly piece weight.

According to a further advantage of the present invention, the tilting actuator is free of parasitic stress. This is accomplished by having the harp remain secured within a channel and operating within a plane parallel to the front surface of the cheese. The actuator is not subject to the forces developed as the cheese passes through the harp.

According to a still further advantage of the present invention, the stroke of the main ram is constant. This advantageously allows the engineers to optimize the operation of the actuator. Since stroke length is constant, optimization of speed and minimization of required actuator requirements can be achieved. This potentially can result in less capital investment and operational costs.

According to a still further advantage yet of the present invention, two vertical support bars are provided. These support bars perform several advantageous functions. First, the vertical bars are contained within slots in the top arm of the invention. The bottom arm of the invention can be stationary, and can have the vertical bars stationarily received within respective holes. The vertical bars then limit the travel of the top arm of the invention relative the bottom arm, as movement of the top arm is limited by the location of the vertical bars within the slots.

A second advantage of the vertical bars is that they provide support to the wires to limit the amount of deflection in the wires.

A third advantage of the vertical bars is that they provide longitudinal support within the mounting system.

According to a still further advantage yet of the present invention, the string tension remains constant within the harp as it is tilted to its selected orientation within a plane generally parallel to the front of the cheese. This is accomplished by having holders act in tandem. The holders can pivot about respective sides of the harp and maintain the parallel alignment of the wires as the harp and wires selectably converge or diverge.

According to a still further advantage yet of the present invention, the harp is easily removable from the machine. Cleaning and maintenance of the harp is easily accomplished. Further, multiple harps having varying wire sizes can be easily and rapidly interchanged.

Other advantages, benefits, and features of the present invention will become apparent to those skilled in the art upon reading the detailed description of the invention and studying the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Looking now toFIGS. 1-3, a preferred embodiment of the overall machine5is illustrated. The machine5has a frame10and can be movably supported by several castors. A drive actuator11is provided. The drive actuator11has a first end13and an opposed second end14. A plate15is attached to end13of a ram. The plate15pushes a block of cheese40(described below) or other product through the cutting or slicing portion of the machine5. The plate15is preferably has a planar front face that lies in a plate plane. It is appreciated that the actuator11is a linear drive actuator, and can be a pneumatic actuator. In one embodiment, the actuator can apply a force of approximately 1000 pounds. It is appreciated that the actuator can provide more or less force without departing from the broad aspects of the present invention.

A channel20is bound within the frame10. The channel20has a top21, a bottom22, sides23and24respectively, a front25and a rear26. The front25preferably lies in a plane that is generally parallel to the plate plane of plate15. A harp50(as described below) is removably received within the channel20.

A harp actuator30is further provided. The harp actuator30has ends31and32. A connector33is provided for removably connecting end32to the harp50. The actuator30can selectably vary the angle of the harp50as described below. Harp actuator30is preferably a linear drive actuator, and can provide approximately sixty pounds of force.

As mentioned, a cheese block40is provided for being cut or sliced by the present invention. It is well understood that other food objects or non-food objects could be cut or sliced without departing from the broad aspects of the present invention. The block40has a top and a bottom, a first side and a second side, and a front45and a rear46. The front45of the block is preferably planar and lies in a block plane that is generally parallel to the plate plane of plate15. Several vertical cuts47can be formed through the block40prior to the block passing through the harp50. The cuts47are made both laterally across the block between the sides and longitudinally between the front45and the rear46.

It is understood that the block40is weighed prior to passing through the harp50. The proper size of each consumer-size piece of product can then be determined in advance of being passed through the harp50. The harp50is adjustable (as described below) so that the product will have the desired size equal to the intended weight. InFIGS. 1-3, the block is shown in a position where it can be weighed and volumetrically measured. After the density is determined, the block can be moved up to the slicing position adjacent ram plate15and the harp50can be adjusted for a desired distance between the wires.

Turning now toFIGS. 4-11, a preferred embodiment of the harp is illustrated. The harp50has a top51, a bottom52, a side53, a side54, a front55and a rear56. The front55preferably lies in a harp plane that is parallel to the plate plane of plate15. The harp50preferably comprises four arms that are pivotally linked at their respective ends. The harp50has a generally parallelogram shape, such that the top51and bottom52remain parallel, and the sides53and54, respectively, remain parallel during the tilting of the harp.

The four arms are a top arm60, a bottom arm80, a first side arm100and a second side arm120. Each of these arms is described below.

Top arm60has a top61and a bottom62, a front63and a rear64, and an end67and an end69. A slot65is through the top arm60from the top61to the bottom62. Slot65is bound by two ends. Slot65is near end67of the top arm60. A second slot66is also provided. The second slot66bound by two ends. Slot65is near the end69of the top arm60. It is appreciated that the ends of the slots, respectively, can act as motion limiters and can define the tilting range of the harp50. A first hole68is through the top arm adjacent the first end67, and a second hole70is through the top arm adjacent end69.

Bottom arm80has a top81and a bottom82, a front83and a rear84, and an end85and an end87. A first hole86is through the bottom arm80adjacent end85, and a second hole88is through the bottom arm adjacent end87. Two vertical holes89and90, respectively, are through the bottom arm80between the ends85and87.

Side arm100has a top101with a hole adjacent thereto. Side arm100also has a bottom103with a hole adjacent thereto. A front105, a rear106and sides107and108are further provided. A series of holes109are illustrated. The holes109preferably extend from the front105and are equally spaced from each other. The holes are spaced apart a selected amount. It is appreciated that the vertical component of the distance between the centers of the holes, respectively, decreases, and the harp approaches maximum convergence, and the vertical component of the distance between the holes is at their maximum at the point of harp maximum divergence.

Side arm120has a top121with a hole adjacent thereto. Side arm120also has a bottom123with a hole adjacent thereto. A front125, a rear126, and sides127and128are further provided. A series of holes129are illustrated. Holes preferably extend from the front125of the arm120and are equally spaced from each other. The holes are spaced apart a selected amount. It is appreciated that the vertical component of the distance between the centers of the holes, respectively, decreases, and the harp approaches maximum convergence, and the vertical component of the distance between the holes is at their maximum at the point of harp maximum divergence.

A connecting arm131is on the side128of the arm120. The connecting arm can project forward of the side arm120and can have an axis that is generally perpendicular to the plane of the harp50

The four arms60,80,100and120are pivotally connected to each other. This is accomplished through the use of pins that extend through the respective holes adjacent the ends of the arms. End67of arm60is pivotally connected to the top101of arm100. The bottom103of arm100is pivotally connected to end85or arm80. End87of arm80is pivotally connected to the bottom123of arm120. The top121of arm120is pivotally connected to the end69or arm60. The parallelogram arrangement of the arms results in an adjustably tiltable harp50. The front55of the harp remains planar within a plane parallel to the plate plane of plate15regardless of the angular orientation of the harp50.

The harp actuator30is pivotally connected to side arm120, and in particular by being pivotally connected with the connecting arm131. The harp actuator30selectably tilts the angle of sidewall120, which in turn causes the top and bottom arms to selectably converge or diverge. Tilting of the harp50adjusts the distance between the wires (described below).

Looking now toFIG. 11, a first holder110is shown. Holder110has an arm111with a first end112and a second end115. A detent113with a wire screw114is at the first end112of the holder. A lip116with a hole117there though is at the second end115of the holder110. A pivot118is further provided. The arm111has a longitudinal axis. The pivot118is generally perpendicular to the longitudinal axis of the arm. The hole117has an axis that is aligned with the longitudinal axis of the arm. The pivot preferably intersects the longitudinal axis of the arm, such that hole117is aligned with the center of the pivot. A holder110A is also illustrated.

Looking now toFIG. 12, a first holder140is shown. Holder140has an arm141with a first end142and a second end145. A detent143with a wire screw144is at the first end142of the holder. A lip146with a hole147there though is at the second end145of the holder140. A pivot148is further provided. The arm141has a longitudinal axis. The pivot148is generally perpendicular to the longitudinal axis of the arm. The hole147has an axis that is aligned with the longitudinal axis of the arm, such that hole147is aligned with the center of the pivot. A holder140A is also illustrated.

It is appreciated that holders110and140may be identical in structure.

It is seen in many FIGS. that a wire150is provided. The wire150has a first end151wound onto screw114and a second end152wound onto screw144. A second wire150A is also illustrated. It is appreciated that wire150and wire150A are parallel, and both have a predetermined wire tension. Wires150and150A remain parallel during the full range of divergence and convergence of the wires. The wires move closer together as the harp converges, and move further apart as the harp diverges. The wires stay parallel due to the fact the holders110and140(and110A and140A) are able to pivot around their respective pivots. In this regard, it is seen that the holders act in tandem.

It is appreciated that there may be more or fewer wires without departing from the broad aspects of the present invention. Further, the holders may be selectively positioned in any hole109and/or129depending on the desired cutting characteristics without departing from the broad aspects of the present invention.

A vertical bar160is provided having a top161and a bottom162. A vertical bar170is also provided having a top171and a bottom172. The bottom162of vertical bar160is received within hole89through the bottom arm80, and the bottom172of vertical bar170is received within hole90through the bottom arm80. The top161of vertical bar160passes through the slot65in the top arm60. In this regard, the top arm60is limited in movement where the ends of the slot contact or engage the bar160. The top171of vertical bar170passes through the slot66in the top arm60. In this regard, the top arm60is limited in movement where the ends of the slot66contact or engage the bar170.

In operation, the machine5can take height, width and length measurements, and a weight measurement, of the block40prior to passing through the harp50. In this regard, the height of the end product pieces can be determined and the harp50can be adjusted accordingly.

Turning now toFIGS. 4-8, the harp50is illustrated to be in a position wherein the wires are in a state of maximum convergence and minimum convergence. In this regard, distance between the wires150and150A is minimized when the harp50is in this illustrated position. The vertical bars160and170are all the way to a first end, respectively, of slots65and66.

Turning now toFIGS. 9 and 10, the harp50is illustrated to be in a position wherein the wires are in a state of maximum divergence and minimum convergence. In this regard, the distance between the wires150and150A is maximized when the harp50is in this illustrated position. The vertical bars160and170are all the way to a second end, respectively, of slots65and66.

It is appreciated that the bars160and170of the present invention contact the wires. The location of this contact is adjacent the path of where the block40will pass. Accordingly, deflection of the wires are eliminated or minimized.

The harp50is easily inserted into and removed from channel20. The channel provides longitudinal support to the harp50.

It is appreciated that specific aspects of the present invention can be applied in series. For example, multiple (two or three) harps may be utilized to make precision sized pieces of material. In this regard, there would be multiple stages wherein a tilting harp of the present invention may be stationed in an alignment to slice in one of the length, width and/or height dimensions.

Thus it is apparent that there has been provided, in accordance with the invention, a machine with a tilting harp that fully satisfies the objects, aims and advantages as set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.