US2751680A

US2751680A - Flaying devices

Info

Publication number: US2751680A
Application number: US432161A
Authority: US
Inventors: Wezel Walter
Original assignee: Firm Schmid & Wezel
Current assignee: Firm Schmid & Wezel
Priority date: 1954-05-25
Filing date: 1954-05-25
Publication date: 1956-06-26
Anticipated expiration: 1973-06-26

Description

June 26, 1956 w, w z 2,751,680

FLAYING DEVICES Filed May 25, 1954 2 Sheets-Sheet l INVENTOR Wa/zer "4929/ ATTORNEX W. WEZEL FLAYING DEVICES June 26, 1956 Filed May '25, 1954 2 Sheets-Sheet 2 R O N E V m ATTORNEY United States Patent FLAYIN G DEVICES Walter Wezel, Maulbronn, Germany, assignor to firm Schmid & Wezel, Maulbronn, Wurttemberg, Germany, an openpartnership organized under the laws of the German Federal Republic Application May 25, 1954, Serial No. 432,161

' Claims. (Cl. 30-219) The present invention relates to mechanical flaying devices.

In flaying devices of the type in question which are found to be particularly useful in abattoirs, the manual force ordinarily required for severing the skin of a slaughteredanimal from the carcass is replaced by mechanical power. Nearly all mechanically actuated devices of this nature comprise two round, toothed cutting discs which, while oscillating past each other, by means of the keenly faceted teeth cut through the connecting tissue between skin and flesh. The cutting dis-cs are fastened to, or held by, a suitably shaped hand piece which, usually, contains the gears for actuating the cutting discs. The gears, in turn, are driven by means of a flexible shaft attached to a suitable power source, such as an electric motor.

The present invention is primarily concerned with the construction of the cutting discs. The novel features which I consider characteristic of my invention are set forth with particularity in the appended claims. The invention itself, however, and any additional objects and advantages thereof will be best understood from the following description of a preferred embodiment when read in connection with the accompanying drawings in which:

Fig. 1 is a partly sectional side elevation of the device, with the housing removed;

Fig. 2 is a sectional view on the line II--II in Fig. 1;

Fig. 3 is a side view of a cutting disc;

Fig. 4 is a sectional view on the line IV--IV in Fig. 3;

Fig. 5 is a detail view of one of the cutting teeth; and

Fig. 6 is an exaggerated illustration of the position of the teeth of the two blades with respect to each other.

Referring more specifically to the drawings, the numeral 11 indicates a hand grip, usually made from wood or plastic, 12 refers to a housing and 13 to a housing cap made from the same material as the hand grip. Held between the housing and the housing cap are two

cutting discs

14, 15 which are rotatably mounted next to each other on a spacer ring 16, positioned about the cap nut 17 held by the cap retaining screw 18.

A bearing cap 19, fastened by means of the screw 20, retains the ball bearings 31 of an eccenter shaft 32 fitted within a needle bearing case 33. The other end of the eccenter shaft is held by a similar ball bearing. Mounted on the eccenter shaft are two

driving levers

34, 35, adapted to oscillate the

cutting discs

14, 15, respectively, in opposite direction and each over an angle of about 10. The

numerals

36, 37 indicate cut-outs in the

housing elements

12, 13 to permit oscillation of the driving levers. The latter are held in position and spaced from each other by means of the end washers 38 and the spacer gasket 39.

A bevel gear wheel 40, keyed at 41 to the eccenter shaft and in engagement with the bevel gear 42 mounted at the end of a shaft 43 serves to actuate the said eccenter shaft and, therethrough, the driving levers and the cutting discs. The gear assembly is secured within the housing by means of staybolts and

nuts

44 and 45, respectively. The shaft 43, held by

ball bearings

46 and 47, is provided with a "ice fish tail jaw 48- at the free end for coupling a flexible shaft thereto. I

The cutting blades of the afore-described preferred embodiment have a diameter of about 2.5 inches and are geared to make about 4,200 oscillations per minute, to cut through connecting tissue while the teeth of the blades pass each other. It is to be noted, in this connection that, while the edges of the teeth must be sharp, the points should be dull in order to prevent cutting of the skin.

Until now, cutting discs such as the

discs

14, 15 have been employed. These discs are entirely flat so that the interior surfaces or, at least, a substantial area of the interior surfaces of the discs are in full contact with. each other. This design. has two disadvantages: in the first place, blood and other oifals entering between the discs frequently cause the surfaces of the discs to stick together, even during such. short intervals as A: to V2 hour, thereby producingv a severe strain upon the flexible shaft and the motor when the work is resumed; secondly, the teeth of the discs must be sharpened very frequently which requires skilled. labor and is extremely time consuming.

In accordance with this invention, the cutting discs are provided with inner surfaces that are. hollow-ground. Moreover, by suitable means the two discs are pressed against each other. As a result, the facets of the teeth of the discs pass each other in the same manner as the cutting edges of a pair of paper shears. The advantage gained from this novel design is (a), a self-sharpening effect and (b), a protection against the entry of blood and other oflals between the discs.

Thus, according to the present invention, the interior surfaces or substantial portions of the interior surfaces of the discs are no longer in contact with each other over an area, but only along an undulate line at the cutting edge and the teeth of the two discs act against each other like a multiplicity of shears or scissors the elements of which are continuously exchanged in position. As with shears or scissors which have blades of a certain elasticity that, instead of being perfectly plain and parallel to each other, are bowed so that the cutting contact moves from the hilt to the point, the cutting contacts of the present device move from the respective bases of two adjacent teeth to the tip of the facets of these teeth and down again to the other bases.

Discs of this novel type are the discs 14a and 15a illustrated in Figs. 3 and 4. In order to keep the discs pressing against each other, circularly arranged series of recesses, such as the recess 50, are provided at the interior surface of at least one of the

housing elements

12, 13, but preferably at both of them. Mounted within these recesses are spring-loaded ball bearings, such as the ball bearing 51. By means of pressure exerted by the springs, the balls, being in rolling contact with the cutting discs or at least with one of the cutting discs, cause these cutting discs to remain in close peripheral proximity to each other.

Until now, cutting discs of a body thickness of about 1.5 mm., diminishing to a thickness of 0.75 mm. at the peripheral section and at the teeth have been considered to be most practical. I have now found that the efiiciency and the output can be materially increased at less effort on the part of the operator, if the cross-section of the teeth portion is further reduced, say along the line 7 shown in Figs. 5 and 6, resulting in elastic teeth having a thickness of only about 0.5 mm.

Fig. 6 depicts in an exaggerated manner the interception of the facets 54 and 55 of the discs 14a and 15a in order to attain the desired self-sharpening of the edges.

Having described my invention, I claim:

1. In a flaying device comprising a hand grip, a housing consisting of two shells, two toothed cutting discs mounted rotatably within, and extending peripherally from, the said housing, an eccentric mounted on an eccentric shaft within the said hand grip, fastened to the said eccentric two driving levers, each adapted to oscillate one of the said cutting discs over an arc of about l0" against the other, a first bevel gear keyed to the eccentric shaft, and in operative alignment with the said first bevel gear a second bevel gear mounted at one end of a drive shaft positioned concentrically within the said hand grip, the improvement consisting of two hollow ground cutting discs the teeth of which are adapted to intercept each other with a self-sharpening effect upon oscillation of the said discs in close proximity with each other and mounting the said discs in close proximity with each other.

2. In a fiaying device according to claim 1, the improvement comprising means of pressing the said hollow ground cutting discs against each other.

3. In a fiaying device according to claim 1, the improvement consisting of circularly spaced recesses provided at the interior surface of at least one of the said housing shells, and, mounted within the said recesses, springloaded ball bearings adapted to exert pressure against the adjacent hollow ground cutting disc to keep the said cutting discs in close peripheral contact with each other.

4. In a fiaying device comprising a hand grip, a housing consisting of two shells, two toothed cutting discs mounted rotatably next to each other within, and extending peripherally from, the said housing, an eccentric mounted on an eccentric shaft within the said hand grip, fastened to the said eccentric two driving levers, each adapted to oscillate one of the said cutting discs over an arc of about 10 against the other, a first bevel gear keyed to the eccentric shaft, and in operative alignment with the said first bevel gear a second bevel gear mounted at one end of a drive shaft positioned concentrically within the said hand grip, the improvement comprising elastic, hollow ground cutting discs provided with faceted teeth in linear cutting contact with each other whereby, as the cutting discs oscillate against each other, the linear cutting contact commences at the respective bases of two adjacent discs, ascends to the tips of their facets and descends to the opposite bases, and means pressing at least an operative portion of said cutting discs against each other.

5. In a cutting device according to claim 4, the improvement consisting in providing opposite cutting discs sufiiciently thin to cause bending of the peripheral area of the cutting discs toward each other.

References Cited in the file of this patent UNITED STATES PATENTS 1,945,247 Wezel Jan. 30, 1934 2,317,177 Carissimi Apr. 20, 1943 FOREIGN PATENTS 678,605 Great Britain Sept. 3, 1952