Scribe saw head assembly for cutting loins

A scribe saw head assembly is provided for a loin puller and has substantially reduced wear and increased life of the assembly components. A pinion assembly includes a pinion shaft and a thrust bearing. The shaft has a flange to support the thrust bearing, which is retained by a pair of retainers. The flange and thrust bearing provides constant contact between the pinion shaft and the standard of the scribe saw assembly, prevents side to side movement of the pinion shaft, and prevents longitudinal floating of the pinion shaft.

FIELD OF THE INVENTION

This invention relates to the meat processing industry, and particularly to a scribe saw head assembly for cutting the loin from the carcass middle.

BACKGROUND OF THE INVENTION

Pork carcasses are typically cut into six initial portions, including the left and right front and hind quarters, and the left and right middles. The loin is part of the middle portion, adjacent the backbone in between the ribs and outer layer of back fat.

The conventional loin puller machine, which separates the loin from the carcass middle, has been substantially unchanged for approximately twenty years. One example of a prior art loin puller is from Acraloc, in Tennesee, as described in their U.S. Pat. No. 5,882,252.

The pork processing industry has had several long-standing problems with conventional loin pullers. In a conventional loin puller, a rotary scribe saw is provided to cut the meat. The scribe saw blade on a conventional loin puller is subject to wear and failure due to loads on the drive shaft. Since the blade operates at approximately 2,000 RPM, wear damage can occur quickly, leading to breakage of the blade. Such excessive wear can be the result of a side load on the drive gear shaft, which deflects the shaft and thereby deflects the blade, which then rubs on the standard. Breakage of the blade is a significant safety hazard.

A typical loin puller can process1,300pork middles per hour. Cutting accuracy is critical. For example, if the scribe saw cuts into the rib bone then the primary meat cutting blade cuts through the bone more than one-quarter inch into the belly underneath. That part or the belly, which later becomes bacon, then falls off causing yield loss. If the scribe saw cut is too shallow, when the meat cutting blade tries to pass through the scribe saw blade path, without the bone being cut all the way through. This partial bone cut results in major bone damage, with chips of broken bone distributed throughout the meat.

Another problem with the conventional loin puller is wear and damage to the various shafts. The pinion, which is mounted on the drive motor shaft, has a tendency to float along the shaft, thereby promoting uneven wear on the motor shaft and associated gears. Furthermore, the pinion shaft is typically connected to a motor drive shaft via a single keyway, which generates pressure on only one side of the motor shaft, which can lead to complete failure of the motor shaft. Also, because the ball bearing between the pinion shaft and motor shaft has very limited contact only at the point where the ball is touching the shafts, the longevity of the bearing, motor shaft, and pinion shaft is compromised. The single bearing use in a conventional loin puller also causes the ring or bevel gear and pinion gear to misalign due to flexing, thereby leading to excessive wear and breakage of the shafts and/or the scribe saw blade.

Therefore, a primary objective of the present invention is the provision of an improved scribe saw head assembly which overcomes the problems of the prior art.

A further objective of the present invention is the provision of a scribe saw head assembly for a loin puller having an improved pinion to minimize wear and damage.

Yet another objective of the present invention is the provision of a loin puller scribe saw assembly having a pinion with a radial flange to support a bearing.

A further objective of the present invention is the provision of a scribe saw head assembly for a loin puller which minimizes risk of shaft or blade damage.

Another objective of the present invention is the provision of a scribe saw head assembly for a loin puller which increases the life expectancy of the scribe saw blade and other components.

Another objective of the present invention is the provision of a scribe saw head assembly for a loin puller which is economical to manufacture, and simple, safe and durable in use.

These and other objectives become apparent from the following description of the invention.

SUMMARY OF THE INVENTION

The scribe saw head assembly includes a pinion assembly with a pinion shaft and a pinion gear mounted on the shaft. The shaft includes an outwardly extending radial flange with a bearing mounted on the shaft adjacent the flange. The flange positions the pinion shaft accurately and consistently on the motor output shaft, and supports the bearing to preclude side to side shifting of the pinion shaft. The flange also precludes longitudinal migration of the pinion shaft on the motor shaft, thus enhancing life of the pinion assembly, as well as the scribe assembly gears.

DETAILED DESCRIPTION OF THE INVENTION

The scribe saw assembly of the present invention is generally designated in the drawings by the reference numeral10. The assembly10is part of a loin puller machine. The scribe saw head assembly10has a standard or head14. The standard14is mounted to a motor housing16with a motor therein having an output or drive shaft. Preferably, the standard14is machined so as to produce a smooth finish, as compared to prior art cast standards. The smooth finish makes cleaning easier and minimizes bacteria traps. The back wall15of the standard14has been increased in thickness by approximately one-half inch, from 0.20″ to 0.70″. More particularly, the standard14has a circular flange18with a plurality of mounting holes20for receiving bolts22which extend through the flange18and into threaded holes in the motor housing16. The flange18also includes a pair of holes24through which pins26extend into the motor housing16. The pins26prevent operational side loads from transferring to the bolts22, thereby preventing the bolts from loosening and becoming lost during operation of the loin puller.

A pinion assembly30and a bevel gear assembly50is disclosed in Applicant's co-pending application Ser. No. 14/950,142, filed Nov. 24, 2015, entitled Loin Puller Scribe Saw Assembly, and which is incorporated herein by reference.

The pinion assembly30is adapted to receive the motor drive shaft. The pinion shaft32also has a threaded output shaft36upon which a pinion gear38is mounted.

The body40of the pinion gear38has a threaded internal bore42to receive the output shaft36. Bearings44, such as needle bearings, are mounted on the pinion body30. The use of the bearings44on the pinion shaft32provides contact substantially along the full length of the shaft, as opposed to a line contact provided by prior art roller bearings. Thus, the needle bearing provides approximately one hundred times more contact for better control of the pinion assembly30, increasing the longevity of the motor shaft, pinion shaft32, and bearing44.

Pinion assembly30extends substantially into the hollow body48of the standard14. The pinion shaft32also includes a pair of external cutouts46, each of which receive a key for providing a tight fit of the pinion to the pinion shaft32. In other words, the external cutouts46form a double key slot. This double cutout and key construction allows for the receipt of multiple lock keys to substantially equal pressure on both sides of the motor shaft, thereby precluding uneven forces on the motor shaft and extending the life of the motor shaft.

A bevel gear assembly50is mounted in the standard14and generally extends perpendicular to the pinion assembly30. The bevel gear assembly50includes a bevel gear52mounted on a bushing54, and a shaft56extending through the gear52, bushing54, and the standard14. The end58of the shaft56is threaded, and extends beyond the back wall of the standard14to receive a retaining nut60. The shaft56extends to a first bearing62fit within the bushing54, and a second bearing64fit within the standard14. The shaft56is locked to the standard14by a pin66to prevent rotation of the shaft56. The pin66extends into a transverse hole68in the shaft56, with the outer end of the pin66being received in a slot or notch formed in the back wall of the standard14.

The gears62,64, which reside within the bushing54, provide substantial contact with the gear shaft56, without the use of a conventional spacer. This construction minimizes or eliminates side loads on the gear shaft56, and thereby prevents deflection of the shaft56, which would otherwise be transferred to the scribe saw blade70.

The scribe saw blade70is mounted to the bevel gear52via four pins72press fit into holes or sockets in the front face of the bevel gear52. The pins72provide constant holding power for the blade70. A grease shield74may reside between the blade70and the bevel gear52to seal the bevel assembly50against exterior contamination. A blade nut can be threadably mounted on the bevel gear ring78to retain the blade70on the bevel gear assembly50. The ring78includes internal threads for threadable coupling of a bear lock nut80.

The depth of cut of the blade70is controlled by an adjustable ski82mounted on the standard14. In a preferred embodiment, the ski82has a mounting bracket comprised of a pair of arms84each having a slot86therein. A bolt88extends through each of the slots86and into the back of the standard14. The vertical position of the ski82can be adjusted by loosening the bolts88and sliding the ski arms up or down via the slots86to a desired position. Then the bolts88are re-tightened to maintain the ski82in the selected position.

The present invention is directed toward improvements to the pinion assembly30. In particular, the pinion shaft32includes a flange33extending radially outwardly. A bearing, such as a thrust bearing, is provided on the shaft32adjacent to the flange33. A washer (preferably hardened)37and a retainer39also mount on the shaft32on the opposite side of bearing35of the flange33so as to capture the bearing35securely, but not so tightly as to block the bearing35. The flange33also contacts an interior wall of the standard14to provide constant contact and preclude side-to-side movement of the pinion shaft32relative to the standard14. The flange33also eliminates longitudinal float of the pinion shaft32along the motor shaft. Thus, the flange33and the bearing35extends the life of the head assembly30by eliminating uneven wear of the various components.